FBLA · National 2026–27

Networking Infrastructures

14 two-page sheets · 28 printable pages · 24 lines per page

Read a sheet, then open “Sources, practice, lab and scope notes” beneath it for questions, answers and the module lab. Plain and colored downloads contain the same notes. Use your browser's Print command for one numbered sheet per page.

Official scope: 2026–27 CONNECT guideline. The notes and companion deck have been reviewed; neither certifies your mastery or a competition result. Objective IDs are local study labels, and source-reading limits are recorded in the source ledger.

Confirm qualification, entry limits and conference-specific rules with your adviser. Studying all four events does not establish eligibility to enter all four.

Network models and LANs

Networking Basics

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Network models and LANs

Page 1 · Lines 1–24

1o Overview
2-> LAN scale and purpose
3-> SOHO, enterprise and datacenter
4o LAN scale and purpose
5-> A LAN connects devices within a limited local site.
6-> It lets endpoints share links, services and local resources.
7-> A switch forwards Ethernet frames using learned MAC locations.
8-> A router forwards IP packets between separate IP networks.
9-> Layer 2 means link-local framing; Layer 3 means IP routing.
10-> An ordinary Layer 2 switch forwards within its VLAN.
11-> A Layer 3 switch can also route between configured networks.
12-> VLANs do not encrypt traffic or prevent all access.
13-> LAN ownership and management depend on the organization.
14o SOHO, enterprise and datacenter
15-> SOHO means small office/home office, usually few users.
16-> An integrated gateway may combine router, Wi-Fi and switching.
17-> Integration saves cost but limits capacity and redundancy.
18-> Enterprise LANs use managed access across campuses.
19-> VLANs and routed boundaries organize traffic and policy.
20-> Central management spreads both settings and errors.
21-> Datacenter LANs connect dense server and storage systems.
22-> Redundant links can improve availability but add complexity.
23-> No LAN guarantees speed, security or uninterrupted service.
24-> Select scale by users, traffic, growth, support and budget.

Network models and LANs

Page 2 · Lines 25–48

25o Overview
26-> Encapsulation across a connection
27-> Switch and router forwarding
28o Encapsulation across a connection
29-> An application creates data for another host or service.
30-> Transport adds headers to form segments or datagrams.
31-> IP adds source and destination addresses in a packet.
32-> The link layer wraps that packet in a local-link frame.
33-> The physical layer transmits frame bits as signals.
34-> The receiver processes headers in reverse order.
35-> Each hop uses link delivery for the next local destination.
36-> A router removes incoming frame and forwards the IP packet.
37-> It builds a new frame appropriate to the outgoing link.
38o Switch and router forwarding
39-> A Layer 2 switch consults its MAC forwarding table.
40-> Unknown unicast may be flooded within the eligible VLAN.
41-> A router examines IP destination and selects a next hop.
42-> Routers separate broadcast domains by default.
43-> A Layer 3 switch can perform routing when configured to do so.
44-> Only ordinary Layer 2 switch operation does not route.
45-> A next hop may be another router, not the destination.
46-> Link rate is not payload throughput because of overhead.
47-> Filtering policy is separate from basic forwarding.
48-> Congestion, link failures and bad routes can cause loss.

Sources, practice, lab and scope notes

Objectives

NI-NB-01
NI-NB-05

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. Trace a browser request to a remote server and explain what a router changes.

Transport and IP headers are carried inside a local-link frame. The router removes the incoming link framing, chooses a next hop by IP routing, and sends the packet in a new outgoing-link frame; link MAC delivery changes hop by hop.

2. Does a switch always mean it cannot route between subnets?

No. An ordinary Layer 2 switch forwards frames within its VLAN, but a Layer 3 switch can route between configured networks. The device label alone does not specify enabled functions.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Expected: Results may show a location difference but cannot isolate its cause. Signal bars and a single speed test do not establish universal range or throughput. No traffic capture, credential collection or network configuration change is needed.

Limitations: OSI is a conceptual model; real Internet protocols do not map perfectly to seven discrete layers. Historical IPv4 class ranges are simplified and must not be used to infer modern CIDR prefixes. Wireless range and 5G performance depend on local environment, hardware, regulation and deployment.

OSI layers and packet forwarding

Networking Basics

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OSI layers and packet forwarding

Page 1 · Lines 1–24

1o Overview
2-> OSI: physical and data link
3-> OSI: network through application
4o OSI: physical and data link
5-> OSI is a seven-layer model, not a product blueprint.
6-> Layer 1 sends bits as electrical, optical or radio signals.
7-> It defines media, signaling and connection properties.
8-> Copper, fiber and radio differ in reach and noise limits.
9-> Layer 2 data link groups bits into frames on a local link.
10-> Ethernet and Wi-Fi link delivery use link-layer addressing.
11-> Switches learn source MAC locations and forward frames.
12-> Frames are link-local; routers reframe packets for each link.
13-> Errors, shared-media collisions or loops disrupt delivery.
14o OSI: network through application
15-> Layer 3 network moves packets between networks using IP.
16-> Routers choose next hops using destination and routing data.
17-> Layer 4 carries process traffic using ports and protocols.
18-> TCP offers ordered delivery and retransmits lost data.
19-> UDP provides datagrams without TCP's delivery guarantees.
20-> Layer 5 organizes dialogs between communicating systems.
21-> Layer 6 presentation represents, encodes or transforms data.
22-> Layer 7 protocols support tasks such as web requests.
23-> Internet protocols do not always fit one OSI layer exactly.
24-> OSI aids troubleshooting; it is not a wire-level recipe.

OSI layers and packet forwarding

Page 2 · Lines 25–48

25o Overview
26-> Network troubleshooting model
27-> LAN design in context
28o Network troubleshooting model
29-> OSI layers provide a shared vocabulary for fault isolation.
30-> No link signal suggests checking power, cable or interface.
31-> A local link can work while IP addressing or routing is wrong.
32-> Transport failure may affect a particular service or port.
33-> Application failure may persist despite working lower layers.
34-> Layer symptoms are clues, not proof of a single cause.
35-> Modern protocol stacks combine functions differently from OSI.
36-> Check end-to-end behavior after repairing a local symptom.
37-> Do not infer security from a device's OSI layer alone.
38o LAN design in context
39-> A small shop may use a compact gateway and switched LAN.
40-> A campus commonly uses managed access and routed boundaries.
41-> Datacenter design focuses on server and storage traffic paths.
42-> Capacity planning considers concurrent users and traffic.
43-> Redundant equipment may share power or cable risks.
44-> Segmentation constrains traffic only with correct policy.
45-> More bandwidth cannot fix a wrong route or weak Wi-Fi.
46-> Skills and maintenance matter alongside equipment cost.
47-> Choose components for the site's actual availability needs.
48-> Document dependencies so outages can be diagnosed efficiently.

Sources, practice, lab and scope notes

Objectives

NI-NB-02
NI-NB-03
NI-NB-04
NI-NB-01
NI-NB-05

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. How does encapsulation change at a router?

A router removes incoming link framing, forwards the IP packet by destination, and creates new framing for the outgoing link.

2. Can any switch route between subnets?

No. Ordinary Layer 2 switches forward frames within a VLAN; Layer 3 switches can route when configured.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Internet access and addressing

Networking Basics

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Internet access and addressing

Page 1 · Lines 1–24

1o Overview
2-> From device to ISP
3-> ISP chain and local limits
4o From device to ISP
5-> A network adapter connects a device to a wired or radio link.
6-> A switch or access point joins devices to the local LAN.
7-> A router joins IP networks and selects a route toward the ISP.
8-> A modem adapts signaling for a provider medium such as coax.
9-> An optical network terminal adapts a fiber access connection.
10-> A gateway may combine modem, routing, switching and Wi-Fi.
11-> The ISP aggregates access and routes to other networks.
12-> Operators interconnect through peering or paid transit.
13-> Available access media depend on the local provider.
14o ISP chain and local limits
15-> A home link does not directly cable to every Internet host.
16-> Traffic crosses local gear, then provider networks.
17-> Fiber, coax, DSL and cellular differ in signaling and reach.
18-> The provider medium and plan constrain the access link rate.
19-> A live physical link does not prove DNS or routing is working.
20-> A reachable router does not prove remote service works.
21-> Power or ISP faults can interrupt a correctly addressed LAN.
22-> Speed tests include remote path and server limitations.
23-> Check link, route, DNS and remote service separately.
24-> One device may combine modem and router functions.

Internet access and addressing

Page 2 · Lines 25–48

25o Overview
26-> IPv4 and IPv6 formats
27-> Subnet calculation example
28o IPv4 and IPv6 formats
29-> IPv4 addresses are 32 bits, commonly shown as four octets.
30-> Each dotted-decimal octet ranges from 0 through 255.
31-> IPv6 addresses are 128 bits, written as hexadecimal groups.
32-> IPv6 uses colons; :: can compress one run of zero groups.
33-> IPv6 greatly expands available address space over IPv4.
34-> IPv6 has a different header and uses Neighbor Discovery.
35-> IPv4 commonly uses ARP on Ethernet links for local resolution.
36-> Dual stack runs IPv4 and IPv6 together during transition.
37-> IPv6 still needs suitable access policy and configuration.
38o Subnet calculation example
39-> For 192.0.2.70/26, six bits remain for host positions.
40-> A /26 block has 64 total addresses.
41-> The aligned block containing .70 starts at 192.0.2.64.
42-> The dotted mask is 255.255.255.192.
43-> Under ordinary LAN convention, .64 is the network address.
44-> The corresponding broadcast address is 192.0.2.127.
45-> Ordinary assignable range is 192.0.2.65 through .126.
46-> State the address-use convention when describing host range.
47-> A /32 denotes one IPv4 address route, not a LAN subnet.
48-> A /31 is a point-to-point exception to ordinary host rules.

Sources, practice, lab and scope notes

Objectives

NI-NB-06
NI-NB-08
NI-NB-07

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. Calculate the network and ordinary LAN usable range for 192.0.2.70/26.

The block has 64 addresses and begins at .64. Mask is 255.255.255.192; ordinary LAN convention treats .64 as network and .127 as broadcast, leaving .65-.126. A /31 point-to-point link is a defined exception.

2. Why are Class A/B/C masks not used to determine a modern prefix?

CIDR uses an explicitly configured prefix length and classless allocation. Historical classes are useful as history, but the address's first octet does not determine its current subnet mask.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

IP formats, CIDR and subnet calculation

Networking Basics

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IP formats, CIDR and subnet calculation

Page 1 · Lines 1–24

1o Overview
2-> IP and MAC addressing
3-> Subnet purpose and CIDR
4o IP and MAC addressing
5-> IP addresses identify interfaces for logical packet delivery.
6-> Routers compare destination IP with network prefixes to route.
7-> MAC addresses identify link-layer interfaces on a local link.
8-> Switches learn source MAC locations to forward local frames.
9-> A router uses a new link frame at each routed hop.
10-> MAC is not the end-to-end Internet destination address.
11-> Address resolution finds a local link address for a next hop.
12-> IP and MAC values alone do not prove identity or permission.
13-> Addresses may be assigned manually or by network services.
14o Subnet purpose and CIDR
15-> A subnet groups addresses sharing a common network prefix.
16-> Subnetting divides blocks for routing and administration.
17-> CIDR writes a prefix length, such as IPv4 /24.
18-> A /24 means 24 leading bits identify the IPv4 prefix.
19-> Its dotted mask is 255.255.255.0; mask bits are contiguous.
20-> IPv4 block size is 2^(32 minus prefix length) addresses.
21-> Network boundaries align to the block size.
22-> CIDR uses explicit prefixes, not inferred address classes.
23-> Subnet design balances growth, address use and broadcasts.
24-> A /31 can assign both addresses on a point-to-point link.

IP formats, CIDR and subnet calculation

Page 2 · Lines 25–48

25o Overview
26-> Historical IPv4 address classes
27-> Addressing and planning limits
28o Historical IPv4 address classes
29-> Class A historically had first octet 1 through 126.
30-> Class B historically had first octet 128 through 191.
31-> Class C historically had first octet 192 through 223.
32-> Class D: first octet 224-239; multicast addresses.
33-> Class E: first octet 240-255; historically experimental.
34-> Special-use values limit these simplified historical ranges.
35-> Classful networks once implied default network masks.
36-> Classless CIDR replaced class-based routing and allocation.
37-> Modern configuration specifies a prefix or mask explicitly.
38o Addressing and planning limits
39-> Size subnets for planned growth without needless waste.
40-> Separate prefixes can simplify routing and management.
41-> Subnetting alone does not block all inter-host traffic.
42-> Routing policy determines which networks can exchange packets.
43-> Plan IPv4 and IPv6 addresses and firewall rules separately.
44-> Special-use ranges are not ordinary public host allocations.
45-> Allocation and reachability depend on provider and setup.
46-> Do not infer a modern prefix from historical class labels.
47-> Verify mask, boundary and host rules for the specific link.
48-> Legacy subnet tutorials may use simplified classful examples.

Sources, practice, lab and scope notes

Objectives

NI-NB-07
NI-NB-09
NI-NB-08

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. Calculate 192.0.2.70/26 network and usable LAN range.

The aligned block is .64-.127 with mask 255.255.255.192; ordinary LAN hosts are .65-.126. /31 point-to-point is an exception.

2. What replaced classful prefix inference?

CIDR uses an explicit prefix length; class labels do not determine modern masks.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Network scope and topologies

Network Topologies and Architecture

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Network scope and topologies

Page 1 · Lines 1–24

1o Overview
2-> Peer-to-peer and client-server
3-> Choose a service architecture
4o Peer-to-peer and client-server
5-> Peer-to-peer devices share resources directly with peers.
6-> Two home computers sharing files are a simple P2P example.
7-> Each peer manages its own resources and access decisions.
8-> P2P avoids a dedicated server but peer availability varies.
9-> Client-server assigns a service role to a server system.
10-> Clients request service, such as files, from that server.
11-> A file server can centralize permissions, storage and backup.
12-> Central services need adequate capacity and recovery plans.
13-> Both models need appropriate access and security controls.
14o Choose a service architecture
15-> Small trusted groups may value P2P simplicity and low cost.
16-> Growing organizations may need centrally managed services.
17-> Server failure can affect many clients at once.
18-> Replicated services may reduce but not eliminate dependencies.
19-> P2P users can make inconsistent copies and permissions.
20-> Server administration needs staffing, patching and monitoring.
21-> Client-server describes service roles, not physical layout.
22-> A server may be virtual or hosted outside the local LAN.
23-> Select based on scale, access control, continuity and budget.
24-> A central server still needs backup and restore testing.

Network scope and topologies

Page 2 · Lines 25–48

25o Overview
26-> Star and bus topologies
27-> Ring and mesh topologies
28o Star and bus topologies
29-> Star connects endpoints to a central switch or access point.
30-> Adding a star endpoint is usually straightforward.
31-> A central switch or uplink fault can disconnect many users.
32-> Bus topology shares a common backbone among connected devices.
33-> Legacy coax Ethernet used bus-like shared media.
34-> A backbone break can interrupt service for many bus devices.
35-> Shared medium can create contention as traffic grows.
36-> Modern switched Ethernet generally uses physical star cabling.
37-> Physical wiring layout and logical forwarding can differ.
38o Ring and mesh topologies
39-> A ring links nodes in a closed path for traffic circulation.
40-> A ring break can interrupt service without alternate paths.
41-> A mesh provides multiple paths between selected network nodes.
42-> Full mesh links every pair; partial mesh links chosen pairs.
43-> Alternative paths can support resilience after a link failure.
44-> More mesh links increase installation and routing complexity.
45-> Wireless mesh relays traffic and consumes shared airtime.
46-> Redundancy helps only when alternate paths are independent.
47-> Loops require controls to prevent repeated frame circulation.
48-> Capacity must support rerouted traffic after a failure.

Sources, practice, lab and scope notes

Objectives

NI-NTA-01
NI-NTA-03
NI-NTA-04

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. A clinic needs easy growth but less dependence on one uplink. What topology change could help?

A switched star is manageable but its central uplink is a failure point. Add an independently routed second uplink or selected mesh path if the cost and operations justify it; redundant paths sharing one conduit are not independent.

2. Contrast P2P file sharing with a client-server file service for multiple branches.

P2P is decentralized with variable availability and separate permission management. Client-server centralizes access and backup, but depends on server capacity and WAN reachability for branches.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Topology selection and wireless LANs

Network Topologies and Architecture

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Topology selection and wireless LANs

Page 1 · Lines 1–24

1o Overview
2-> LAN, MAN and WAN scope
3-> WAN implications and scale
4o LAN, MAN and WAN scope
5-> LAN means local area network across a limited site or campus.
6-> A MAN spans a metropolitan or city region.
7-> A WAN joins distant sites across larger geographic areas.
8-> WAN links often depend on telecom or Internet providers.
9-> Routers connect local networks across inter-site links.
10-> Geographic scope does not specify ownership or a fixed speed.
11-> WAN distance often increases latency and service cost.
12-> Provider outages can affect several connected locations.
13-> A VPN protects a path; it cannot prevent provider outages.
14o WAN implications and scale
15-> A company WAN may link branches, headquarters and datacenters.
16-> Applications sensitive to delay need realistic WAN testing.
17-> Bandwidth and latency are distinct performance properties.
18-> A MAN may be provider-operated or organization-managed.
19-> LAN typically supports local switching and local services.
20-> WAN agreements specify capacity and availability terms.
21-> Backup circuits help only if routes and infrastructure differ.
22-> A remote site still relies on its local LAN and gateway.
23-> Choose scope from users, geography and application needs.
24-> No topology name guarantees a particular reliability level.

Topology selection and wireless LANs

Page 2 · Lines 25–48

25o Overview
26-> Choose topology for requirements
27-> Wireless network size options
28o Choose topology for requirements
29-> A small office often uses a switched star for easy management.
30-> A critical site may add diverse uplinks for availability.
31-> A partial mesh trades extra paths against cost and complexity.
32-> Legacy bus is rarely a new Ethernet installation choice.
33-> Compare failure impact, growth, traffic and operator skills.
34-> A central star switch is a possible single point of failure.
35-> Separate power and physical routes improve path independence.
36-> No topology is best for every business requirement.
37-> Physical cabling choices also constrain speed and distance.
38o Wireless network size options
39-> A small LAN may use an integrated Wi-Fi router or one AP.
40-> An access point bridges wireless clients to a wired LAN.
41-> Large campuses deploy multiple managed access points.
42-> AP placement should account for coverage and client density.
43-> Wired backhaul avoids radio retransmission at every hop.
44-> Managed systems coordinate settings and may support roaming.
45-> Cloud management adds provider and Internet dependencies.
46-> Survey results vary with walls, interference and location.
47-> More APs do not automatically create better coverage.
48-> All network sizes need secure settings and monitoring.

Sources, practice, lab and scope notes

Objectives

NI-NTA-02
NI-NTA-03
NI-NTA-04
NI-NTA-05

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. How can a clinic reduce a star uplink failure risk?

Add an independent uplink or partial mesh if cost and operations justify it; shared pathways are not independent.

2. Why might campuses deploy managed access points?

Multiple managed APs provide planned coverage and capacity, but need backhaul, configuration and ongoing management.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Cloud models and trade-offs

Network Topologies and Architecture

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Cloud models and trade-offs

Page 1 · Lines 1–24

1o Overview
2-> Cloud definition and service models
3-> Service model use and responsibility
4o Cloud definition and service models
5-> Cloud offers on-demand access to shared computing resources.
6-> Resources include networks, servers, storage and applications.
7-> Cloud resources can be rapidly provisioned and released.
8-> IaaS provides configurable compute, storage and networking.
9-> IaaS customers usually manage guest systems and applications.
10-> PaaS supplies a platform for customers to deploy applications.
11-> PaaS provider manages more underlying runtime infrastructure.
12-> SaaS delivers a provider-operated application to its users.
13-> Service models distinguish provider and customer control.
14o Service model use and responsibility
15-> IaaS suits teams needing control of virtual machines.
16-> PaaS runs customer code on a provider-managed platform.
17-> SaaS suits organizations using a finished hosted application.
18-> Provider duties differ by service and contract.
19-> Customers still manage identities, access and data use.
20-> Shared responsibility does not remove customer duties.
21-> A hosted service depends on its provider and network path.
22-> Clarify backup, retention and recovery terms before adoption.
23-> Cloud describes a delivery model, not one physical location.
24-> Service boundaries vary, so verify the actual offer terms.

Cloud models and trade-offs

Page 2 · Lines 25–48

25o Overview
26-> Radio frequency and attenuation
27-> Wireless speed and reliability
28o Radio frequency and attenuation
29-> Radio frequency (RF) carries wireless signals through space.
30-> Distance generally weakens received signal strength.
31-> Walls and building materials absorb or reflect radio energy.
32-> Metal and reinforced concrete can obstruct or reflect signals.
33-> Interference and noise can corrupt reception or cut capacity.
34-> A client and access point both need adequate signal quality.
35-> A strong signal does not guarantee a fast Internet connection.
36-> Range depends on frequency, antenna, power and environment.
37-> No single indoor Wi-Fi range applies to every building.
38o Wireless speed and reliability
39-> Wi-Fi PHY rate is a signaling maximum, not app throughput.
40-> Overhead and retransmissions reduce usable throughput.
41-> Congestion shares airtime among nearby clients.
42-> Channel width and modulation affect capacity and reach.
43-> Client capability can limit an AP's advertised link rate.
44-> Backhaul capacity can bottleneck otherwise strong Wi-Fi.
45-> Roaming, power and configuration affect reliability.
46-> Survey at actual user locations and test representative load.
47-> Higher AP power may not strengthen a client's return signal.
48-> Band, regulation and hardware determine available channels.

Sources, practice, lab and scope notes

Objectives

NI-NTA-06
NI-NTA-08

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. A company selects hosted email. Identify the cloud model and two retained concerns.

Hosted email is SaaS because the provider delivers the application. The customer still manages user access and data decisions, and should confirm recovery and retention responsibilities; service terms define the boundary.

2. Why might a 5G user near a window have different service than indoors?

Radio band, distance, building attenuation, spectrum and local cell deployment affect reception. 5G service categories describe system goals, not guaranteed end-to-end performance at every location.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Wireless performance and 5G

Network Topologies and Architecture

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Wireless performance and 5G

Page 1 · Lines 1–24

1o Overview
2-> Cloud benefits and operating costs
3-> Cloud risks and planning
4o Cloud benefits and operating costs
5-> On-demand provisioning can shorten deployment time.
6-> Elastic resources can scale with changing workload demand.
7-> Measured service ties some costs to consumption.
8-> Less local hardware can reduce some maintenance work.
9-> Usage charges, licenses and support create ongoing costs.
10-> Data transfer and storage can add to monthly bills.
11-> Migration and staff learning require time and resources.
12-> Variable demand can make costs difficult to forecast.
13-> Cloud is not automatically cheaper than local infrastructure.
14o Cloud risks and planning
15-> Provider outages can make hosted services unavailable.
16-> Misconfigured permissions can expose data or resources.
17-> Provider dependence can make migration or exit difficult.
18-> Location and retention of data affect compliance obligations.
19-> Plan access controls and recovery responsibilities in advance.
20-> Assess portability and export options before committing.
21-> Use budgets and alerts to monitor measured consumption.
22-> Provider safeguards do not replace correct customer setup.
23-> Availability depends on app, network and provider systems.
24-> Compare risks and costs with the business continuity need.

Wireless performance and 5G

Page 2 · Lines 25–48

25o Overview
26-> Wireless LAN and cellular options
27-> 5G system and service families
28o Wireless LAN and cellular options
29-> IEEE 802.11 defines WLAN medium access and physical layers.
30-> Wi-Fi commonly links local devices through access points.
31-> Cellular networks provide operator-managed wide-area mobility.
32-> Wi-Fi generally uses local access points and backhaul.
33-> Unlicensed Wi-Fi bands can be crowded by neighboring networks.
34-> Cellular coverage depends on operator deployment and spectrum.
35-> Large campus Wi-Fi requires placement and capacity planning.
36-> Small networks may use a single integrated wireless gateway.
37-> Neither Wi-Fi nor cellular has one universal speed or range.
38o 5G system and service families
39-> 5G is a 3GPP mobile system, not a single radio frequency.
40-> A 5G system includes user equipment, radio access and core.
41-> 5G New Radio (NR) is the radio interface family.
42-> Enhanced mobile broadband targets high data-rate services.
43-> Massive IoT targets communication for many connected devices.
44-> Critical communications target reliability and low latency.
45-> Network slicing can tailor logical network capabilities.
46-> Service goals depend on deployment and end-to-end path.
47-> Low latency is not guaranteed for every 5G application.
48-> Spectrum, obstacles and distance affect coverage and capacity.

Sources, practice, lab and scope notes

Objectives

NI-NTA-07
NI-NTA-05
NI-NTA-08
NI-NTA-09

Sources

The OSI Model — fetched; Read overview and layer descriptions: seven-layer conceptual troubleshooting model, including functions of application through physical layers; modern Internet does not strictly map to OSI.
RFC 791: Internet Protocol — fetched; Read abstract and introductory IP operation material on connectionless datagrams, addressing, routing and gateways.
RFC 8200: IPv6 Specification — fetched; Read specification overview and IPv6 addressing/header material; grounds IPv6 protocol facts.
RFC 4632: Classless Inter-domain Routing — fetched; Read abstract and prefix notation sections: explicit prefix lengths and classless address assignment/aggregation.
Configure IP Addresses and Unique Subnets — fetched; Read IP/subnet definitions, dotted decimal explanation and subnet examples; older tutorial, classful assumptions are historical only.
NIST Definition of Cloud Computing — fetched; Read NIST SP 800-145 abstract and definition: on-demand shared configurable resources, rapid provisioning/release, measured service and IaaS/PaaS/SaaS models.
5G System Overview — fetched; Read 3GPP introduction, system architecture and service descriptions: UE, radio access network and core; eMBB, massive IoT and critical/URLLC goals. Goals are not universal service guarantees.
IEEE 802.11 Working Group — fetched; Read working-group scope describing WLAN MAC and PHY standardization; this does not support universal range or throughput figures.

Practice (answers below)

1. Why can Wi-Fi signal be strong but throughput poor?

Congestion, protocol overhead, client limits or backhaul bottlenecks can reduce throughput despite signal strength.

2. What are 5G service families intended to support?

eMBB targets data rates, massive IoT many devices, and critical/URLLC services reliability and latency goals; these are not guarantees.

Safe local Wi-Fi observation

Predict which of two authorized indoor locations has weaker Wi-Fi and explain why.
Using only a network you are authorized to use, record the signal indicator and one ordinary download result at each location.
Repeat at a different time and discuss walls, congestion, device limits and Internet path as possible causes.

Network Security Controls

Network Security

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Network Security Controls

Page 1 · Lines 1–24

1o Overview
2-> Risk and Security Goals
3-> Controls and Malware Defense
4o Risk and Security Goals
5-> Asset value and exposure shape security risk.
6-> Threat is a possible harmful actor or event.
7-> Vulnerability is a weakness that can be exploited.
8-> Exploit is a method or code using that weakness.
9-> Risk combines likelihood and impact in context.
10-> Unpatched public software raises exposure, not certainty.
11-> Insiders, mistakes, suppliers, and outsiders create risk.
12-> Zero-day is unknown to responsible defenders or vendors.
13-> Confidentiality limits disclosure to authorized parties.
14o Controls and Malware Defense
15-> Integrity means preserving data accuracy and completeness.
16-> Availability means timely access to authorized users.
17-> Account lifecycle removes stale users and excess access.
18-> Authentication verifies a claimed identity or authenticator.
19-> Authorization decides allowed actions; permissions enforce it.
20-> Encryption obscures content without the required key.
21-> Antivirus detects known or suspicious patterns; misses occur.
22-> Mail and web filters reduce risky links and attachments.
23-> Patching removes known flaws after suitable testing.
24-> Disable unused services; verify needed network flows first.

Network Security Controls

Page 2 · Lines 25–48

25o Overview
26-> Availability and Attack Paths
27-> Integrity, Identity, and Recovery
28o Availability and Attack Paths
29-> DoS denies service by exhausting a constrained resource.
30-> Floods may saturate links or consume server request capacity.
31-> Protocol attacks can exhaust connection or state tables.
32-> Application floods consume workers, memory, or CPU.
33-> DDoS distributes traffic across many compromised devices.
34-> Botnets coordinate infected devices for distributed attacks.
35-> Distributed sources complicate filtering and attribution.
36-> Phishing impersonates trusted senders to prompt unsafe action.
37-> Spoofing forges apparent sender, address, or device identity.
38o Integrity, Identity, and Recovery
39-> Poisoning corrupts trusted lookup data, such as DNS cache.
40-> Hash maps data to a fixed-size digest; it is not encryption.
41-> A trusted digest comparison can reveal changed file contents.
42-> An unauthenticated hash does not prove who supplied the file.
43-> Digital signature uses private key; public key verifies it.
44-> Signatures prove integrity/key origin, not secrecy.
45-> Certificate binds identity and public key under issuer policy.
46-> Validate certificate chain, name, validity, and trust.
47-> MFA uses distinct factors; RADIUS supports remote access.
48-> SSO reuses login; TACACS+ separates device AAA functions.

Sources, practice, lab and scope notes

Objectives

NI-NS-01
NI-NS-02
NI-NS-07
NI-NS-03
NI-NS-04
NI-NS-08
NI-NS-05
NI-NS-06
NI-NS-09
NI-NS-10

Sources

CommScope Category 6A Cables — fetched; Read the manufacturer explanation that Cat 6A structured cabling supports 10 Gigabit Ethernet channels up to 100 m. This is conditional channel capability, not a guarantee for every device, optic, or installation.
CISA phishing and DoS guidance — fetched; DoS flooding, overload, botnet/distributed effects; phishing page also fetched for warning signs.
NIST SP 800-63-4 Digital Identity Guidelines — fetched; Publication scope describes proofing, authentication, authenticators, federation and assertions; technical detail here limited to those concepts.
NIST FIPS 180-4 Secure Hash Standard — fetched; Digests detect changed messages; hash standard publication overview.
RFC 4271 BGP-4 — fetched; Abstract and status: inter-AS reachability, AS paths, policy, CIDR; Standards Track.
RFC 2328 OSPFv2 — fetched; Abstract: link-state, intra-AS topology database, shortest-path tree, areas and equal-cost paths.
RFC 7868 EIGRP — fetched; Abstract/status: distance-vector basis, DUAL, informational not Standards Track.
RFC 959 FTP — fetched; FTP purpose and control/data transfer model.
RFC 4217 Securing FTP with TLS — fetched; FTP TLS extension and security/authentication mechanisms; distinguishes FTPS from SFTP.
RFC 5321 SMTP — fetched; SMTP electronic mail transport and submission role.
RFC 1035 DNS — fetched; DNS query/response and record formats.
RFC 2131 DHCP — fetched; DHCP address allocation and host configuration framework.
RFC 9293 TCP — fetched; TCP transport protocol specification.
RFC 768 UDP — fetched; Datagram service; delivery and duplicate protection not guaranteed.
RFC 3022 Traditional NAT — fetched; Address translation and NAPT address/port mapping; informational RFC.
RFC 8446 TLS 1.3 — fetched; TLS channel design goal against eavesdropping, tampering and message forgery.
RFC 2865 RADIUS — fetched; Read abstract and operation: NAS exchanges authentication, authorization and configuration with shared server; assigned UDP port 1812; limitations noted.
RFC 8907 TACACS+ — fetched; Read introduction: centralized device administration; authentication, authorization and accounting are separate; TCP port 49; informational status and deployment cautions.
IANA Service Name and Port Number Registry — fetched; Read the CSV rows for TCP 21 FTP control, 22 SSH, 25 SMTP, TCP/UDP 53 domain, UDP 67 bootps and 68 bootpc, TCP 80 HTTP, UDP 123 NTP, TCP 443 HTTPS, TCP 465 submissions, and TCP 587 submission. Registry reservations do not imply every service uses all registered transports or that a port guarantees security.
Cisco Ethernet Auto-Negotiation Guide — fetched; Operational 10/100/1000 Ethernet negotiation and NIC/switch compatibility; not a normative distance table.
Cisco Wireless RF Reference Guide — fetched; Read Wi-Fi generations table, band discussions, RF fundamentals; table maximum link rates are conditional and not throughput promises.
Cisco Ethernet Auto-Negotiation Guide — fetched; Read operational Ethernet speed/duplex negotiation and compatibility tables; this source does not establish PHY distances.
Cisco Catalyst 9800 WPA3 Configuration Guide — fetched; WPA3 SAE exchange, online/offline guessing resistance, AP/client compatibility and supported configurations.
Cisco Ethernet 10BaseT and 100BaseTX Cable Specs — fetched; Read tables showing Ethernet PHY media, 10BaseT 100m and 100BaseTX 100m segment; legacy guide, use only for named variants.
Cisco Nexus 7000 Transceiver Specifications — fetched; Read transceiver tables; optical reach varies with model, fiber grade, wavelength and loss budget.

Practice (answers below)

1. Explain the four terms in a risk example involving an unpatched server.

The threat is a possible attacker/event, the flaw is the vulnerability, exploit is the method used, and risk reflects likelihood and impact for that exposed asset.

2. Why is a hash neither encryption nor proof of author?

It produces a digest for change detection, not reversible secrecy; absent a trusted signature or channel an attacker can replace both content and digest.

Paper network protocol trace

Diagram a client obtaining DHCP settings and resolving a DNS name.
Trace a TCP or UDP service to a gateway and describe NAT separately from firewall policy.
Compare OSPF internal routes with BGP inter-AS advertisements and EIGRP RFC status.
Estimate wireless deployment only after recording band, obstacles, client capabilities, and load.
Select a named Ethernet PHY and check its copper or fiber medium assumptions.
Compare WPA2/WPA3 configuration and note device compatibility; use no live attack traffic.

Expected: DHCP, DNS, IP, and gateway roles are distinguished. Port defaults are not treated as exclusive or protective. Routing protocol scope and standards status are correct. RF range and throughput are expressed conditionally. Ethernet reach is tied to PHY and medium.

Limitations: Cisco RF guide (2024) includes generation/link-rate table, but table cites secondary material and its maxima are not guarantees. Cisco Ethernet cable guide is older and supports only listed PHY/cable cases; validate other media/reaches against exact transceiver datasheets. WPA3 notes use Cisco 17.15 configuration guide and apply only to supported combinations.

Network Threats and Mitigation

Network Security

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Network Threats and Mitigation

Page 1 · Lines 1–24

1o Overview
2-> Malware and Social Engineering
3-> Resilient Defensive Layers
4o Malware and Social Engineering
5-> Virus attaches to host content and runs when executed.
6-> Worm self-propagates; it need not attach to a host file.
7-> Trojan disguises harmful code as useful software.
8-> Logic bomb triggers when a time or condition is met.
9-> Ransomware blocks or encrypts data for extortion.
10-> Phishing arrives through email, text, call, or fake site.
11-> Urgency and unexpected credential requests are warning signs.
12-> Spoofing falsifies identity; verify sender independently.
13-> Poisoning alters trusted data so later lookups mislead users.
14o Resilient Defensive Layers
15-> Filter risky links/files; scanners cannot catch every sample.
16-> Verify payment or password requests through known channels.
17-> Patch exposed systems and retire unsupported software.
18-> Least privilege limits damage from stolen accounts or malware.
19-> Segmentation restricts paths to critical systems.
20-> Backups aid recovery; isolate copies from normal admin access.
21-> Test restores because untested copies may be incomplete.
22-> Close unused ports only after checking service dependencies.
23-> Firewall rules filter traffic; they cannot stop all attacks.
24-> Monitor logs and alerts; sensors require review and response.

Network Threats and Mitigation

Page 2 · Lines 25–48

25o Overview
26-> DoS Mechanics
27-> Mitigation and Residual Risk
28o DoS Mechanics
29-> A volumetric flood consumes available link bandwidth.
30-> A protocol flood consumes connection or device state.
31-> An application flood forces costly valid-looking work.
32-> Reflection sends third-party replies to a victim.
33-> Amplification makes replies larger than triggering requests.
34-> Forged source addresses can obscure origins in some floods.
35-> Botnet DDoS adds traffic from many compromised endpoints.
36-> A firewall cannot restore a saturated upstream link.
37-> Outages deny service to legitimate users.
38o Mitigation and Residual Risk
39-> Upstream filtering or scrubbing can remove attack traffic.
40-> Rate limits reduce abusive request rates but need tuning.
41-> Redundancy and capacity help only within design limits.
42-> Broad filters may block legitimate clients too.
43-> Coordinate with providers when circuit capacity is exceeded.
44-> Report phishing; do not click, reply, or share approval codes.
45-> Antivirus and filters complement user verification.
46-> Preserve logs and follow incident response procedures.
47-> No single control guarantees service or prevents compromise.
48-> Review residual risk as systems and attacker methods change.

Sources, practice, lab and scope notes

Objectives

NI-NS-02
NI-NS-04
NI-NS-06
NI-NS-03
NI-NS-08
NI-NS-05

Sources

CommScope Category 6A Cables — fetched; Read the manufacturer explanation that Cat 6A structured cabling supports 10 Gigabit Ethernet channels up to 100 m. This is conditional channel capability, not a guarantee for every device, optic, or installation.
CISA phishing and DoS guidance — fetched; DoS flooding, overload, botnet/distributed effects; phishing page also fetched for warning signs.
NIST SP 800-63-4 Digital Identity Guidelines — fetched; Publication scope describes proofing, authentication, authenticators, federation and assertions; technical detail here limited to those concepts.
NIST FIPS 180-4 Secure Hash Standard — fetched; Digests detect changed messages; hash standard publication overview.
RFC 4271 BGP-4 — fetched; Abstract and status: inter-AS reachability, AS paths, policy, CIDR; Standards Track.
RFC 2328 OSPFv2 — fetched; Abstract: link-state, intra-AS topology database, shortest-path tree, areas and equal-cost paths.
RFC 7868 EIGRP — fetched; Abstract/status: distance-vector basis, DUAL, informational not Standards Track.
RFC 959 FTP — fetched; FTP purpose and control/data transfer model.
RFC 4217 Securing FTP with TLS — fetched; FTP TLS extension and security/authentication mechanisms; distinguishes FTPS from SFTP.
RFC 5321 SMTP — fetched; SMTP electronic mail transport and submission role.
RFC 1035 DNS — fetched; DNS query/response and record formats.
RFC 2131 DHCP — fetched; DHCP address allocation and host configuration framework.
RFC 9293 TCP — fetched; TCP transport protocol specification.
RFC 768 UDP — fetched; Datagram service; delivery and duplicate protection not guaranteed.
RFC 3022 Traditional NAT — fetched; Address translation and NAPT address/port mapping; informational RFC.
RFC 8446 TLS 1.3 — fetched; TLS channel design goal against eavesdropping, tampering and message forgery.
RFC 2865 RADIUS — fetched; Read abstract and operation: NAS exchanges authentication, authorization and configuration with shared server; assigned UDP port 1812; limitations noted.
RFC 8907 TACACS+ — fetched; Read introduction: centralized device administration; authentication, authorization and accounting are separate; TCP port 49; informational status and deployment cautions.
IANA Service Name and Port Number Registry — fetched; Read the CSV rows for TCP 21 FTP control, 22 SSH, 25 SMTP, TCP/UDP 53 domain, UDP 67 bootps and 68 bootpc, TCP 80 HTTP, UDP 123 NTP, TCP 443 HTTPS, TCP 465 submissions, and TCP 587 submission. Registry reservations do not imply every service uses all registered transports or that a port guarantees security.
Cisco Ethernet Auto-Negotiation Guide — fetched; Operational 10/100/1000 Ethernet negotiation and NIC/switch compatibility; not a normative distance table.
Cisco Wireless RF Reference Guide — fetched; Read Wi-Fi generations table, band discussions, RF fundamentals; table maximum link rates are conditional and not throughput promises.
Cisco Ethernet Auto-Negotiation Guide — fetched; Read operational Ethernet speed/duplex negotiation and compatibility tables; this source does not establish PHY distances.
Cisco Catalyst 9800 WPA3 Configuration Guide — fetched; WPA3 SAE exchange, online/offline guessing resistance, AP/client compatibility and supported configurations.
Cisco Ethernet 10BaseT and 100BaseTX Cable Specs — fetched; Read tables showing Ethernet PHY media, 10BaseT 100m and 100BaseTX 100m segment; legacy guide, use only for named variants.
Cisco Nexus 7000 Transceiver Specifications — fetched; Read transceiver tables; optical reach varies with model, fiber grade, wavelength and loss budget.

Practice (answers below)

1. A service loses access during a large distributed flood. What is the mechanism and a likely response?

DDoS sends traffic from many compromised systems, possibly exhausting link, state, or app capacity. Upstream scrubbing may be needed if the circuit is saturated; rate limits help only for suitable traffic.

2. A caller urgently requests an MFA code to prevent account closure. How should staff respond?

Treat as possible phishing/impersonation, never disclose the code, verify using a known contact route, and report it. Encryption does not stop a user giving a secret to an impostor.

Paper network protocol trace

Diagram a client obtaining DHCP settings and resolving a DNS name.
Trace a TCP or UDP service to a gateway and describe NAT separately from firewall policy.
Compare OSPF internal routes with BGP inter-AS advertisements and EIGRP RFC status.
Estimate wireless deployment only after recording band, obstacles, client capabilities, and load.
Select a named Ethernet PHY and check its copper or fiber medium assumptions.
Compare WPA2/WPA3 configuration and note device compatibility; use no live attack traffic.

Network Protocols and Services

Network Protocols and Standards

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Network Protocols and Services

Page 1 · Lines 1–24

1o Overview
2-> File and Mail Protocols
3-> DNS, DHCP, and IP
4o File and Mail Protocols
5-> FTP transfers files through control and data connections.
6-> FTP control commonly listens on TCP port 21 by default.
7-> FTP active/passive modes change data connection ports.
8-> Plain FTP does not protect credentials or contents in transit.
9-> FTPS adds TLS to FTP; SFTP is file transfer over SSH.
10-> SFTP commonly uses TCP port 22, the SSH default.
11-> SMTP transfers mail between systems and supports submission.
12-> SMTP relay commonly uses TCP 25; submission often uses 587.
13-> TCP 465 often means implicit-TLS submission; configs vary.
14o DNS, DHCP, and IP
15-> DNS answers name queries with records such as IP addresses.
16-> DNS commonly uses UDP 53; TCP 53 is also required.
17-> DHCP supplies leases and network settings to hosts.
18-> DHCPv4 commonly uses UDP 67 server and 68 client.
19-> A lease may include address, mask, router, and DNS server.
20-> DHCP relay can carry client requests across routed subnets.
21-> DHCP address is host configuration, not permanent identity.
22-> DNS name resolution does not itself route packets to a host.
23-> Gateway forwards traffic beyond the local IP subnet.
24-> Stale or poisoned DNS data can direct clients incorrectly.

Network Protocols and Services

Page 2 · Lines 25–48

25o Overview
26-> Transport and Port Defaults
27-> NAT and Secure Service Use
28o Transport and Port Defaults
29-> TCP provides an ordered byte stream with retransmission.
30-> TCP setup and recovery add overhead; delivery is not instant.
31-> UDP sends datagrams without TCP delivery/order guarantees.
32-> Applications may add reliability above UDP when needed.
33-> IP carries packets; TCP/UDP ports identify endpoints.
34-> HTTP commonly uses TCP 80; HTTPS commonly TCP 443.
35-> SSH commonly uses TCP 22; service ports can be changed.
36-> DNS uses UDP or TCP 53; blocking TCP can break functions.
37-> NTP commonly uses UDP 123; defaults are not exclusive rules.
38o NAT and Secure Service Use
39-> NAT maps IP addresses between address realms.
40-> NAPT also maps transport ports for multiple inside hosts.
41-> Home gateways commonly share one public IPv4 address.
42-> Translation conserves addresses; it does not encrypt packets.
43-> NAT is not a firewall policy or authentication mechanism.
44-> A stateful firewall separately permits or denies flows.
45-> Inbound reachability may need mapping and explicit policy.
46-> TLS aims to protect channels from eavesdropping and tampering.
47-> Use secure transfer; configure TLS and verify peer identity.
48-> Service configuration, not port number, determines exposure.

Sources, practice, lab and scope notes

Objectives

NI-NPS-01
NI-NPS-07
NI-NPS-02
NI-NPS-05
NI-NPS-08

Sources

CommScope Category 6A Cables — fetched; Read the manufacturer explanation that Cat 6A structured cabling supports 10 Gigabit Ethernet channels up to 100 m. This is conditional channel capability, not a guarantee for every device, optic, or installation.
CISA phishing and DoS guidance — fetched; DoS flooding, overload, botnet/distributed effects; phishing page also fetched for warning signs.
NIST SP 800-63-4 Digital Identity Guidelines — fetched; Publication scope describes proofing, authentication, authenticators, federation and assertions; technical detail here limited to those concepts.
NIST FIPS 180-4 Secure Hash Standard — fetched; Digests detect changed messages; hash standard publication overview.
RFC 4271 BGP-4 — fetched; Abstract and status: inter-AS reachability, AS paths, policy, CIDR; Standards Track.
RFC 2328 OSPFv2 — fetched; Abstract: link-state, intra-AS topology database, shortest-path tree, areas and equal-cost paths.
RFC 7868 EIGRP — fetched; Abstract/status: distance-vector basis, DUAL, informational not Standards Track.
RFC 959 FTP — fetched; FTP purpose and control/data transfer model.
RFC 4217 Securing FTP with TLS — fetched; FTP TLS extension and security/authentication mechanisms; distinguishes FTPS from SFTP.
RFC 5321 SMTP — fetched; SMTP electronic mail transport and submission role.
RFC 1035 DNS — fetched; DNS query/response and record formats.
RFC 2131 DHCP — fetched; DHCP address allocation and host configuration framework.
RFC 9293 TCP — fetched; TCP transport protocol specification.
RFC 768 UDP — fetched; Datagram service; delivery and duplicate protection not guaranteed.
RFC 3022 Traditional NAT — fetched; Address translation and NAPT address/port mapping; informational RFC.
RFC 8446 TLS 1.3 — fetched; TLS channel design goal against eavesdropping, tampering and message forgery.
RFC 2865 RADIUS — fetched; Read abstract and operation: NAS exchanges authentication, authorization and configuration with shared server; assigned UDP port 1812; limitations noted.
RFC 8907 TACACS+ — fetched; Read introduction: centralized device administration; authentication, authorization and accounting are separate; TCP port 49; informational status and deployment cautions.
IANA Service Name and Port Number Registry — fetched; Read the CSV rows for TCP 21 FTP control, 22 SSH, 25 SMTP, TCP/UDP 53 domain, UDP 67 bootps and 68 bootpc, TCP 80 HTTP, UDP 123 NTP, TCP 443 HTTPS, TCP 465 submissions, and TCP 587 submission. Registry reservations do not imply every service uses all registered transports or that a port guarantees security.
Cisco Ethernet Auto-Negotiation Guide — fetched; Operational 10/100/1000 Ethernet negotiation and NIC/switch compatibility; not a normative distance table.
Cisco Wireless RF Reference Guide — fetched; Read Wi-Fi generations table, band discussions, RF fundamentals; table maximum link rates are conditional and not throughput promises.
Cisco Ethernet Auto-Negotiation Guide — fetched; Read operational Ethernet speed/duplex negotiation and compatibility tables; this source does not establish PHY distances.
Cisco Catalyst 9800 WPA3 Configuration Guide — fetched; WPA3 SAE exchange, online/offline guessing resistance, AP/client compatibility and supported configurations.
Cisco Ethernet 10BaseT and 100BaseTX Cable Specs — fetched; Read tables showing Ethernet PHY media, 10BaseT 100m and 100BaseTX 100m segment; legacy guide, use only for named variants.
Cisco Nexus 7000 Transceiver Specifications — fetched; Read transceiver tables; optical reach varies with model, fiber grade, wavelength and loss budget.

Practice (answers below)

1. A workstation has no address and cannot look up a server name. Which roles should be checked?

Check DHCP lease and options for IP, gateway, and DNS server; DNS resolves the name, then IP routing and gateway carry traffic to the destination.

2. Does a gateway using NAT automatically make an exposed service safe?

No. NAT rewrites addresses/ports and may limit unsolicited inbound mapping, but it is not encryption or access policy; a firewall, authentication, patching, and service configuration remain necessary.

Paper network protocol trace

Diagram a client obtaining DHCP settings and resolving a DNS name.
Trace a TCP or UDP service to a gateway and describe NAT separately from firewall policy.
Compare OSPF internal routes with BGP inter-AS advertisements and EIGRP RFC status.
Estimate wireless deployment only after recording band, obstacles, client capabilities, and load.
Select a named Ethernet PHY and check its copper or fiber medium assumptions.
Compare WPA2/WPA3 configuration and note device compatibility; use no live attack traffic.

Routing, Ethernet, and Wireless

Network Protocols and Standards

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Routing, Ethernet, and Wireless

Page 1 · Lines 1–24

1o Overview
2-> Wireless Generations and Bands
3-> Wireless Range and Throughput
4o Wireless Generations and Bands
5-> 802.11b uses 2.4 GHz DSSS; max PHY rate is 11 Mb/s.
6-> 802.11a uses 5 GHz OFDM; max PHY rate is 54 Mb/s.
7-> 802.11g uses 2.4 GHz OFDM; max PHY rate is 54 Mb/s.
8-> 802.11n (Wi-Fi 4) supports 2.4/5 GHz and MIMO.
9-> 802.11ac (Wi-Fi 5) operates in 5 GHz bands.
10-> 802.11ax (Wi-Fi 6) supports 2.4 and 5 GHz operation.
11-> Wi-Fi 6E adds 6 GHz where permitted and supported.
12-> 802.11be (Wi-Fi 7) adds multi-link in capable devices.
13-> Max PHY rates require matching channel and radio capability.
14o Wireless Range and Throughput
15-> There is no single universal indoor Wi-Fi range figure.
16-> Band, walls, antennas, power, and receivers affect reach.
17-> 2.4 GHz often travels farther through walls than 5/6 GHz.
18-> 2.4 GHz is often more congested; local spectrum matters.
19-> Channel width, streams, and interference affect PHY rate.
20-> App throughput is below PHY rate due to overhead/contention.
21-> Clients share airtime; slow stations reduce capacity.
22-> Regulatory domain limits channels and transmit power.
23-> Survey user locations and load before estimating coverage.
24-> A repeater can extend reach but consumes airtime or adds hops.

Routing, Ethernet, and Wireless

Page 2 · Lines 25–48

25o Overview
26-> Ethernet PHY and Medium
27-> Routing and Wireless Protection
28o Ethernet PHY and Medium
29-> 10BASE-T is 10 Mb/s over twisted-pair copper, up to 100 m.
30-> 100BASE-TX is 100 Mb/s copper, up to 100 m channel.
31-> 1000BASE-T carries 1 Gb/s over four pairs, up to 100 m.
32-> 10GBASE-T can reach 100 m on Cat 6A compliant channel.
33-> Cat 6 10GBASE-T reach depends on channel and alien crosstalk.
34-> 1000BASE-SX uses multimode fiber; reach varies by grade.
35-> 1000BASE-LX reach depends on optics and fiber type.
36-> 10GBASE-SR uses multimode fiber; distance depends on fiber.
37-> IEEE PHY, optics, connectors, and loss set fiber reach.
38o Routing and Wireless Protection
39-> OSPF is link-state routing within an autonomous system.
40-> OSPF routers build topology databases and calculate paths.
41-> BGP exchanges inter-AS prefixes and paths for policy.
42-> BGP is an IETF Standards Track protocol.
43-> EIGRP uses DUAL, a distance-vector-based routing algorithm.
44-> RFC 7868 is Informational, not an IETF Standards Track spec.
45-> WPA2 deployments can use AES-CCMP; avoid legacy TKIP.
46-> WPA3-Personal SAE strengthens resistance to offline guessing.
47-> WPA3 connections require Protected Management Frames.
48-> Negotiated security depends on AP/client configuration.

Sources, practice, lab and scope notes

Objectives

NI-NPS-03
NI-NPS-04
NI-NPS-06
NI-NPS-09

Sources

CommScope Category 6A Cables — fetched; Read the manufacturer explanation that Cat 6A structured cabling supports 10 Gigabit Ethernet channels up to 100 m. This is conditional channel capability, not a guarantee for every device, optic, or installation.
CISA phishing and DoS guidance — fetched; DoS flooding, overload, botnet/distributed effects; phishing page also fetched for warning signs.
NIST SP 800-63-4 Digital Identity Guidelines — fetched; Publication scope describes proofing, authentication, authenticators, federation and assertions; technical detail here limited to those concepts.
NIST FIPS 180-4 Secure Hash Standard — fetched; Digests detect changed messages; hash standard publication overview.
RFC 4271 BGP-4 — fetched; Abstract and status: inter-AS reachability, AS paths, policy, CIDR; Standards Track.
RFC 2328 OSPFv2 — fetched; Abstract: link-state, intra-AS topology database, shortest-path tree, areas and equal-cost paths.
RFC 7868 EIGRP — fetched; Abstract/status: distance-vector basis, DUAL, informational not Standards Track.
RFC 959 FTP — fetched; FTP purpose and control/data transfer model.
RFC 4217 Securing FTP with TLS — fetched; FTP TLS extension and security/authentication mechanisms; distinguishes FTPS from SFTP.
RFC 5321 SMTP — fetched; SMTP electronic mail transport and submission role.
RFC 1035 DNS — fetched; DNS query/response and record formats.
RFC 2131 DHCP — fetched; DHCP address allocation and host configuration framework.
RFC 9293 TCP — fetched; TCP transport protocol specification.
RFC 768 UDP — fetched; Datagram service; delivery and duplicate protection not guaranteed.
RFC 3022 Traditional NAT — fetched; Address translation and NAPT address/port mapping; informational RFC.
RFC 8446 TLS 1.3 — fetched; TLS channel design goal against eavesdropping, tampering and message forgery.
RFC 2865 RADIUS — fetched; Read abstract and operation: NAS exchanges authentication, authorization and configuration with shared server; assigned UDP port 1812; limitations noted.
RFC 8907 TACACS+ — fetched; Read introduction: centralized device administration; authentication, authorization and accounting are separate; TCP port 49; informational status and deployment cautions.
IANA Service Name and Port Number Registry — fetched; Read the CSV rows for TCP 21 FTP control, 22 SSH, 25 SMTP, TCP/UDP 53 domain, UDP 67 bootps and 68 bootpc, TCP 80 HTTP, UDP 123 NTP, TCP 443 HTTPS, TCP 465 submissions, and TCP 587 submission. Registry reservations do not imply every service uses all registered transports or that a port guarantees security.
Cisco Ethernet Auto-Negotiation Guide — fetched; Operational 10/100/1000 Ethernet negotiation and NIC/switch compatibility; not a normative distance table.
Cisco Wireless RF Reference Guide — fetched; Read Wi-Fi generations table, band discussions, RF fundamentals; table maximum link rates are conditional and not throughput promises.
Cisco Ethernet Auto-Negotiation Guide — fetched; Read operational Ethernet speed/duplex negotiation and compatibility tables; this source does not establish PHY distances.
Cisco Catalyst 9800 WPA3 Configuration Guide — fetched; WPA3 SAE exchange, online/offline guessing resistance, AP/client compatibility and supported configurations.
Cisco Ethernet 10BaseT and 100BaseTX Cable Specs — fetched; Read tables showing Ethernet PHY media, 10BaseT 100m and 100BaseTX 100m segment; legacy guide, use only for named variants.
Cisco Nexus 7000 Transceiver Specifications — fetched; Read transceiver tables; optical reach varies with model, fiber grade, wavelength and loss budget.

Practice (answers below)

1. Why can Wi-Fi 6E not guarantee better speed or a fixed larger range?

6 GHz support and PHY maxima depend on client/AP capability, permitted channels, interference, channel width, walls, power and shared airtime. Actual coverage and throughput require local measurement.

2. Which protocol suits internal topology routing versus inter-provider reachability, and what is EIGRP's RFC status?

OSPF is an intra-AS link-state protocol; BGP exchanges inter-AS reachability under policy. EIGRP uses DUAL, and RFC 7868 is Informational rather than Standards Track.

Paper network protocol trace

Diagram a client obtaining DHCP settings and resolving a DNS name.
Trace a TCP or UDP service to a gateway and describe NAT separately from firewall policy.
Compare OSPF internal routes with BGP inter-AS advertisements and EIGRP RFC status.
Estimate wireless deployment only after recording band, obstacles, client capabilities, and load.
Select a named Ethernet PHY and check its copper or fiber medium assumptions.
Compare WPA2/WPA3 configuration and note device compatibility; use no live attack traffic.

Network Hardware Links and Media

Network Hardware and Connectivity

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Network Hardware Links and Media

Page 1 · Lines 1–24

1o Overview
2-> From provider to host
3-> Network adapters and local traffic
4o From provider to host
5-> An ISP supplies service over a provider network.
6-> A modem terminates a provider-specific signal.
7-> An ONT terminates a fiber access service handoff.
8-> Either handoff can present Ethernet to a router.
9-> Some gateways combine modem or ONT and router.
10-> A router forwards IP packets between networks.
11-> Its WAN side faces service; LAN serves local hosts.
12-> A Layer 2 switch forwards LAN frames using MACs.
13-> A switch does not replace the WAN router function.
14o Network adapters and local traffic
15-> A NIC joins a host to a wired or wireless link.
16-> It sends and receives link-layer frames.
17-> A PCIe NIC is a physical card fitted to a slot.
18-> A virtual NIC is a software interface for a VM.
19-> The host's virtual switch can connect virtual NICs.
20-> Path: provider, modem/ONT, router, LAN switch, host.
21-> One appliance may implement several path functions.
22-> The ISP service and working provider network are also needed.
23-> Without Internet, local switched communication may still work.
24-> Ethernet frames use MAC addressing on the local link.

Network Hardware Links and Media

Page 2 · Lines 25–48

25o Overview
26-> Copper media
27-> Fiber and link compatibility
28o Copper media
29-> Twisted-pair copper carries signals on paired conductors.
30-> Twisting helps reduce crosstalk between wire pairs.
31-> UTP means unshielded twisted pair; it lacks cable shielding.
32-> STP means shielded twisted pair; foil or braid screens pairs.
33-> Shield benefit depends on correct bonding and installation.
34-> Coax has a central conductor, dielectric and outer shield.
35-> Coax carries cable broadband and some legacy Ethernet.
36-> Twisted pair often uses an 8P8C modular plug.
37-> Coax commonly uses F-type or BNC connectors.
38o Fiber and link compatibility
39-> Single-mode fiber has a small core for one light mode.
40-> Multimode fiber has a larger core carrying multiple modes.
41-> LC and SC name connector form factors, not fiber modes.
42-> Corning lists LC products for both single and multimode fiber.
43-> Connector fit alone does not make transceivers compatible.
44-> Match mode, wavelength, optics, connector and Ethernet PHY.
45-> Check both endpoint datasheets and the optical loss budget.
46-> Fiber reach depends on PHY, optics, fiber grade and loss.
47-> 100 m copper channels are common, not a universal PHY limit.
48-> Never look into fiber ends; use disconnected samples only.

Sources, practice, lab and scope notes

Objectives

NI-NHC-01
NI-NHC-06
NI-NHC-02
NI-NHC-03
NI-NHC-04

Sources

Red Hat Enterprise Linux 9: Managing RAID — fetched; Read overview and section 18.3 definitions for striping, mirroring, parity, RAID 6 recovery after any two drive losses, and Linux MD RAID 10 variants. The notes qualify the conventional four-disk mirrored-pair RAID 10 layout; Linux MD can support other layouts, including three drives.
FBLA Networking Infrastructures 2026-27, pp. 5-6 — fetched; Read the current Network Hardware and Connectivity objectives; establishes assignment scope, not the technical explanations.
Cisco: What Is Ethernet? — fetched; Read Ethernet media, IEEE 802.3, Layer 1/2, MAC frames and switching, router packet forwarding between networks, Ethernet cabling and power. Cisco learning explanation; not a universal reach or product compatibility specification.
Cisco UCS 5100 Series Blade Server Chassis Data Sheet — fetched; Read chassis capacity, shared power supplies, hot-swappable fans, fabric/midplane, redundancy options and integrated management details; this is one specific blade implementation, not a universal blade design.
Corning: Heat-Cure Connector, LC — fetched; Read manufacturer product description and variants: LC connectors offered for single-mode and multimode fiber, with distinct fiber categories and UPC/APC options. Illustrates that connector family alone does not establish optics compatibility.
Microsoft Learn: Storage Spaces Direct fault tolerance — fetched; Read mirror and parity mechanisms, single/dual parity tradeoffs and failure tolerance tables. Storage Spaces Direct is a software-defined clustered implementation; used only to explain mirror/parity concepts, not as a claim that its server counts equal disk counts for RAID.

Practice (answers below)

1. Trace a PC's link to the ISP and state what routes off the LAN.

The NIC links to the switch, which forwards local frames. The router forwards packets between LAN and ISP handoff; modem or ONT terminates the provider medium. Integrated devices may combine roles.

2. Why does an LC plug not prove an optical link will work?

LC identifies connector form, but fiber mode, wavelength, transceiver and Ethernet PHY must also match; validate endpoint specifications and loss budget.

Offline hardware and storage tabletop

Draw provider, handoff, router, switch and host; label each role.
On paper, compare NAS files with SAN block volumes and RAID layouts.
Use disconnected cable samples or photographs; do not inspect live fiber.
Check a sample switch datasheet for total and per-port PoE limits.

Expected: Learner distinguishes WAN routing from local frame switching. Learner identifies fiber mode and optic compatibility checks. Learner distinguishes file access, block access and backup copies. Learner states both PoE constraints must meet device demand.

Limitations: Cisco UCS 5108 details describe one blade platform, not every chassis. Exact STP, UTP and coax performance varies by cable construction and PHY; no universal reach is asserted. RAID level tolerance describes conventional layouts; controller, implementation and failure scenario matter. Microsoft Storage Spaces Direct is related parity/mirroring evidence, not an identical RAID implementation. Cisco Networking Academy course page was not readable when fetched and is not claimed as read.

Server and Storage Infrastructure

Network Hardware and Connectivity

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Server and Storage Infrastructure

Page 1 · Lines 1–24

1o Overview
2-> Rack and blade server forms
3-> Chassis power and connectivity
4o Rack and blade server forms
5-> A rack server is an individual server mounted in a rack.
6-> It generally has its own power and cooling components.
7-> Racks allow mixed systems and incremental installation.
8-> They require rack space, cabling and room-level cooling.
9-> A blade is a server module fitted into a shared chassis.
10-> The chassis can provide power, fans, fabric and management.
11-> Shared infrastructure can reduce cabling and increase density.
12-> Chassis cost and blade compatibility constrain choice.
13-> Shared power, cooling or midplane can form failure domains.
14o Chassis power and connectivity
15-> Cisco UCS 5108 holds up to eight half-width blade servers.
16-> Its chassis has hot-swappable power supplies and fans.
17-> Its fabric connects blades to network interfaces and uplinks.
18-> That design reduces separate chassis switches and cabling.
19-> Redundant supplies or fans reduce, but do not erase, risk.
20-> Power redundancy mode determines tolerated supply loss.
21-> PoE supplies data and power over supported Ethernet links.
22-> Check the switch's total PoE budget and each port limit.
23-> Also verify device demand and the exact equipment datasheet.
24-> Internet needs ISP, handoff hardware, router and host link.

Server and Storage Infrastructure

Page 2 · Lines 25–48

25o Overview
26-> File and block storage
27-> RAID and fault tolerance
28o File and block storage
29-> NAS means network-attached storage, typically shared files.
30-> Clients request named files and folders over LAN protocols.
31-> SAN commonly presents block volumes to connected hosts.
32-> A host formats and manages a block volume as a disk.
33-> NAS suits shared files; SAN can serve host-managed blocks.
34-> Choice depends on workload, protocol, administration and cost.
35-> Neither guarantees a particular speed or availability.
36-> A storage network does not itself provide backup copies.
37-> Protect data separately against deletion and site loss.
38o RAID and fault tolerance
39-> RAID combines disks for speed, redundancy, or both.
40-> RAID 0 stripes data; 2+ disks, no disk-failure tolerance.
41-> Two-disk RAID 1 mirrors data; survives one member failure.
42-> RAID 5 uses single parity; 3+ disks, tolerates one disk loss.
43-> RAID 6 uses dual parity; 4+ disks, tolerates two disk losses.
44-> Conventional RAID 10 stripes mirrored pairs; minimum 4 disks.
45-> RAID 10 tolerates one loss per pair, not both in one pair.
46-> RAID limits assume supported layouts and healthy members.
47-> Rebuilds take time; extra failures can exceed level limits.
48-> RAID is not backup; keep separate copies and test restores.

Sources, practice, lab and scope notes

Objectives

NI-NHC-05
NI-NHC-06
NI-NHC-07

Sources

Red Hat Enterprise Linux 9: Managing RAID — fetched; Read overview and section 18.3 definitions for striping, mirroring, parity, RAID 6 recovery after any two drive losses, and Linux MD RAID 10 variants. The notes qualify the conventional four-disk mirrored-pair RAID 10 layout; Linux MD can support other layouts, including three drives.
FBLA Networking Infrastructures 2026-27, pp. 5-6 — fetched; Read the current Network Hardware and Connectivity objectives; establishes assignment scope, not the technical explanations.
Cisco: What Is Ethernet? — fetched; Read Ethernet media, IEEE 802.3, Layer 1/2, MAC frames and switching, router packet forwarding between networks, Ethernet cabling and power. Cisco learning explanation; not a universal reach or product compatibility specification.
Cisco UCS 5100 Series Blade Server Chassis Data Sheet — fetched; Read chassis capacity, shared power supplies, hot-swappable fans, fabric/midplane, redundancy options and integrated management details; this is one specific blade implementation, not a universal blade design.
Corning: Heat-Cure Connector, LC — fetched; Read manufacturer product description and variants: LC connectors offered for single-mode and multimode fiber, with distinct fiber categories and UPC/APC options. Illustrates that connector family alone does not establish optics compatibility.
Microsoft Learn: Storage Spaces Direct fault tolerance — fetched; Read mirror and parity mechanisms, single/dual parity tradeoffs and failure tolerance tables. Storage Spaces Direct is a software-defined clustered implementation; used only to explain mirror/parity concepts, not as a claim that its server counts equal disk counts for RAID.

Practice (answers below)

1. Compare a blade chassis with individual rack servers for a growing site.

Blades can raise density and centralize power, cooling and fabric, but depend on chassis capacity, compatibility and shared components. Rack servers are more individually replaceable and flexible but use rack space and separate cabling. Compare site power/cooling, service model and failure domains.

2. Which level has dual parity, and why can it not replace a backup?

RAID 6 uses dual parity, needs at least four disks in the standard level, and tolerates up to two disk losses under its assumptions. RAID cannot recover independent copies after deletion, malware or site loss; keep tested separate backups.

Offline hardware and storage tabletop

Draw provider, handoff, router, switch and host; label each role.
On paper, compare NAS files with SAN block volumes and RAID layouts.
Use disconnected cable samples or photographs; do not inspect live fiber.
Check a sample switch datasheet for total and per-port PoE limits.