2950 to 2950?

Please let me know if this has been answered before, but how do you connect 2 2950 switches back to back? I've tried a straight through and a cross over cable and don't get link lights for either. Is there some configuration on the switch I'm missing?

Thank you!

Find more posts tagged with

SAVE $250 on Your CISCO Boot Camp — Use Code "EXAM26"

Exclusively for TechExams members for Infosec Boot Camps starting before April 30, 2026

View CISCO Boot Camps

Comments

yanks4everontop

Jaguar0616 wrote: »

Please let me know if this has been answered before, but how do you connect 2 2950 switches back to back? I've tried a straight through and a cross over cable and don't get link lights for either. Is there some configuration on the switch I'm missing?

Thank you!

You need a crossover cable as I created a thread asking the same thing a few days ago. Are you sure the interfaces and vlan1 (assuming it's the default vlan) are active?

waymorr

You need a crossover cable and you also need to configure a port on each switch to trunk mode this will then allow your 2 switches to communicate.

Stotic

switchport trunk encapsulation dot1q
switchport mode trunk

phantasm

All of the above should get you there. The 2950's do not have Auto MDI as far as I know. Therefore you will need a croxx-over cable and you will need to configure the port as a trunk port with the dot1q trunking.

networker050184

You don't need to configure your ports as a trunk for the switches to communicate. Get the physical connection up first, then worry about trunking.

kalebksp

FYI, 2950s don't support ISL, so the "switchport trunk encapsulation" command is not applicable.

jbaello

kalebksp wrote: »

FYI, 2950s don't support ISL, so the "switchport trunk encapsulation" command is not applicable.

I was just checking the encapsulation type, 2950 should already have 802.1q as it's default encapsulation it's the only one available, ISL is legacy and being faded out, the 3550 still has this.

Stotic

Stotic wrote: »

switchport trunk encapsulation dot1q
switchport mode trunk

I actually just came back because I remembered what others have said above. You do not need to specify encapsulation on a 2950 because ISL has been decontinued on them.

redboynono

don't need config anything if the cross cable is good

miller811

redboynono wrote: »

don't need config anything if the cross cable is good

unless the port is configured to not allow communication.

just in case

issue the default int f0/X on both sides of the connection.
In the default state the swtiches should link if the cross over cable is functional.