Connect 3 Cisco switches via ethernet ports?

Question

We have been using 2 Cisco 2960-S 48 Port switches which were connected together using a regular Cat5e cable and everything was working fine, however we have purchased a 3rd switch of the same model and need to connect it to the other switches.

What would be the best way to connect all 3 switches?

The switches will be in a ring like this:

          switch 1
         /        \
        /          \
switch 2------------switch 3

On another site on an old thread I found, someone said this would cause a loop and cause problems.

Can anyone shed any light on if this config would work or cause any problems?

Any help greatly appreciated!

Answer 1

We have been using 2 Cisco 2960-S 48 Port switches which were connected together using a regular Cat5e cable and everything was working fine, however we have purchased a 3rd switch of the same model and need to connect it to the other switches.

What would be the best way to connect all 3 switches?

Generally, you connect all three switches in a "triangle". There is no problem with this configuration as long as you have some version of spanning-tree running.

I'm not sure what state your network is in right now, so I'm assuming you might not have spanning-tree running, and you have not connected the third switch. Generic steps to introduce the new switch:

1. Make sure the third switch is disconnected. Configure spanning-tree mode rapid-pvst on all switches.
2. Configure spanning-tree vlan 1-4094 priority 4096 on the switch closest to your Internet / WAN connection
3. Configure spanning-tree vlan 1-4094 priority 8192 on the other (running) switch
4. Configure spanning-tree portfast disable on all ports connecting to the other switches.

I gave you a very basic recipe to make this work... depending on the bandwidth needs of the clients, you might want to bundle multiple links between these switches with LACP or EtherChannel.