Cisco – Why this topology’s links are red

cisco

I made this topology and some of the links are red, I enabled all the interfaces though

Best Answer

Simple, you need to use "Straight Cable"

Straight Cable:

Usually use straight cable to connect different type of devices. This type of cable will be used most of the time and can be used to:

1) Connect a computer to a switch/hub's normal port.

2) Connect a computer to a cable/DSL modem's LAN port.

3) Connect a router's WAN port to a cable/DSL modem's LAN port.

4) Connect a router's LAN port to a switch/hub's uplink port. (Normally used for expanding network)

5) Connect two switches/hubs with one of the switch/hub using an uplink port and the other one using normal port.

If you need to check how straight cable looks like, it's easy. Both sides (side A and side B) of cable have wire arrangement with same color.

Crossover Cable:

Sometimes you will use crossover cable, it's usually used to connect same type of devices. A crossover cable can be used to:

1) Connect two computers directly.

2) Connect a router's LAN port to a switch/hub's normal port. (Normally used for expanding network)

3) Connect two switches/hubs by using normal port in both switches/hubs.

Source:Check This Link

crossover cable vs straight through

Here is thing, you need to do! Packet Tracer