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New Member

Trunking between CatOS and IOS

I recently inherited a 4006, which I'm attempting to trunk with our 3750 stack. I have fast ethernet ports on both ends set up to trunk according to the instructions here:

I'm unable to get the connection to come up. Neither port shows up as a trunk port, but I assume this is normal until they're able to establish a connection with another trunk port. I am able to get a connection by plugging a laptop into the interface on either switch. I have also verified that the VTP configuration is the same on both ends. Any suggestions?

  • LAN Switching and Routing
Hall of Fame Super Silver

Re: Trunking between CatOS and IOS

Hello Jeff,

I apologize it is a basic question, have you tried to use an RJ-45 cross-over cable ?

because you say the port does not come up I would point at a cabling issue

Hope to help



Re: Trunking between CatOS and IOS

Either use a crossover or set the port speed and duplex on each end to auto/auto and enable the mdix function on the 3750 and it should come active .

New Member

Re: Trunking between CatOS and IOS

Thanks for the replies, guys. It is indeed working with a crossover cable. Most of our trunk ports are fiber, so I didn't even give MDIX a thought.

New Member

Re: Trunking between CatOS and IOS

If all interfaces supported auto-MDIX life would be much easier :-)


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