Inter switch trunking

chris.colley · ‎03-29-2007

Got 2 switches connected together as follows

port f0/26 on a cisco WS-C2950C-24 to port g0/48 on a cisco WS-C2960G-48TC-L

They are auto sensing speed and duplex and I cannot find a command to tie them down.

The problem is that WS-C2950C-24 is auto sensing the duplex as full and WS-C2960G-48TC-L is auto sensing the duplex as half

I have coppied the show ver, show int and the interface config from both switches in a notepad attachment

I hope someone can help me with this

Amit Singh · ‎03-29-2007

Chris,

Can you please let us know the GBIC module you are using on 2960G Switch. Your 2950 switch port is 100 base FX and I think you also have a GBIC on 2960G as well.

-amit singh

chris.colley · ‎04-02-2007

Hi there yes the GBIC in the 2960G is a GLC-FE-100FX

Amit Singh · ‎04-02-2007

Hello Chris,

It looks like the SFP on 2960 port doesnot support "auto-negotiation" and falling back on half-duplex. Please try configuring the duplex as full under the SFP interface configuration.

Config t

Switch(config)#Interface ge x/y

Switch(config-if)#media-type sfp

Switch(config-if)#duplex full

http://www.cisco.com/en/US/products/ps6406/products_configuration_guide_chapter09186a0080511fcc.html#wp1080632

This should take care of the problem.

HTH,Please rate if it does.

-amit singh