Lesson 4: Internet and Network Types SOHO Lab

A small-office network makes more sense when you build it from the outside in.

Start with the provider service, identify the handoff, then follow traffic toward the router, switch, access point, and endpoints.

That sequence makes the WAN/LAN boundary visible instead of hiding it inside a wireless gateway icon.

Internet access technologies change the first boundary

Different provider services have different physical characteristics and handoff devices.

Cable

Cable service commonly arrives over coax and terminates at a cable modem or gateway.

DSL

DSL uses supported telephone-line infrastructure and a DSL modem or gateway.

Fiber

Fiber service commonly reaches an ONT before customer-facing Ethernet or gateway equipment.

Cellular

Cellular internet uses radio access through supported carrier infrastructure and a cellular modem, hotspot, or router.

WISP

A wireless internet service provider may use fixed wireless equipment between the customer site and provider network.

Satellite

Satellite internet adds a long radio path and can have different latency and coverage characteristics from terrestrial wired services.

Do not rank these with one universal "fastest" answer.

Availability, latency, bandwidth, physical environment, provider design, and cost all matter.

WAN and LAN describe different scopes

A LAN is a local area network, such as devices inside a classroom, home, or small office.

A WAN connects networks across larger geographic or provider boundaries.

In a SOHO design, the provider-facing side of the router is part of the WAN relationship while the inside switch and AP network is the LAN.

A WLAN is the wireless portion of a local network.

Those labels describe scope, not specific brands of equipment.

PAN, MAN, and SAN solve different scope or purpose problems

PAN

A personal area network covers very short-range personal-device connections, such as a phone paired to a Bluetooth headset.

MAN

A metropolitan area network spans a city or metropolitan region.

SAN

A storage area network is designed around networked storage traffic and infrastructure.

These terms are easy to memorize and easy to forget because they are just labels until you connect them to what is being linked and why.

Build the SOHO topology

Use a fictional office with:

• provider connection;
• provider handoff device;
• router and firewall;
• switch;
• wired workstations;
• network printer;
• access point;
• wireless laptops and phones.

A generic topology might look like:

provider
   ↓
modem / ONT / wireless edge
   ↓
router + firewall
   ↓
managed switch
   ├── workstation
   ├── printer
   ├── server / NAS
   └── access point
          ))) wireless clients

Now the roles from Lesson 1 have somewhere to live.

Choose private addressing deliberately

For the lab, use a private or documentation-safe design.

Example:

LAN: 192.168.40.0/24
router LAN: 192.168.40.1
DHCP pool: 192.168.40.100-199
printer static or reserved: 192.168.40.20

The exact numbers matter less than the relationships.

The printer needs to be on the intended subnet. DHCP clients need a valid gateway. A statically assigned address must not collide with the dynamic pool unless the design explicitly controls that allocation.

Address planning prevents troubleshooting later.

Decide which endpoints should be static or dynamic

Typical user endpoints are often good DHCP candidates because centralized dynamic configuration is easier to manage.

Some infrastructure or service devices may need predictable addresses through static configuration, DHCP reservation, or another managed strategy.

The point is predictability for the service, not "servers always static" as a magic phrase.

Use the network's actual management method.

PoE affects AP placement

An access point mounted on a ceiling may be far from an electrical outlet.

PoE can deliver power and data over the Ethernet run if:

• the switch or injector provides the required standard and power;
• cabling supports the installation;
• the AP supports the source.

That can simplify placement while adding a power dependency to the switch or injector.

When the AP goes dark, the fault could be the Ethernet data path, the PoE source, or the endpoint itself.

Fault 1: provider reaches modem, router WAN is disconnected

Evidence:

provider / cable modem status: normal
router WAN cable: disconnected
LAN devices: can communicate locally
internet: unavailable

What does local communication prove?

The inside LAN is working well enough for local traffic.

The failure sits between the router and provider handoff.

Do not reset every workstation.

Fault 2: ONT has service, router lacks valid WAN configuration

The physical provider handoff can be healthy while the router has no usable upstream IP configuration.

Again, link and configuration are separate layers.

Fault 3: endpoint receives APIPA

The endpoint has a local link address instead of the expected DHCP configuration.

Place the failure around address acquisition before blaming DNS or the internet provider.

Fault 4: AP is linked but unpowered

If the switch port carries data but does not provide required PoE, the AP may never start.

The Wi-Fi problem begins as a power-design problem.

Fault 5: valid local address, wrong gateway

Same-subnet communication may still work while remote paths fail.

The local network is not dead.

The endpoint's route out of the subnet is wrong.

Build the design record

Document:

• provider connection type;
• provider handoff device;
• router and gateway role;
• switch type;
• PoE requirement;
• AP placement;
• IPv4 private subnet;
• static and dynamic plan;
• IPv6 expectation;
• LAN, WLAN, and WAN boundaries;
• one PAN example;
• one SAN or MAN example in context;
• two injected faults and how the topology helps isolate them.

Before you move on

A small network should now look like a chain of responsibilities:

provider medium
   ↓
provider handoff
   ↓
router / gateway / firewall
   ↓
switching
   ↓
wired or wireless access
   ↓
endpoint IP configuration

Next we troubleshoot the local side of that chain and prove exactly how far an endpoint can communicate before saying "the internet is down."