01-15-2008 05:42 AM - edited 03-05-2019 08:28 PM
Hello all -
I have two 3550's and I have trunking enabled on the fast ethernet ports. I have tried to set both ends to 100/full, however they do not come up. If I go back and set them both to auto/auto they come up. Can I not set trunk ports to 100/full?
Thanks,
Matt
01-15-2008 05:50 AM
Interesting. I don't see why not. Maybe it has some strange interaction with DTP. How are you forming your trunks, desirable-desirable, desirable-auto, or what? Did the ports come up in access mode, or did they not come up at all?
You could try debug dtp all
Kevin Dorrell
Luxembourg
01-15-2008 05:56 AM
They are desirable on both ends. If I do a debug dtp all, what would I be looking for? Trunk status?
01-15-2008 06:29 AM
It sounds like you are using a straight-thru cable vs a cross-over cable. Once you configure the speed and duplex you are automatically disabling Auto-MDIX (http://www.cisco.com/en/US/tech/tk389/tk214/technologies_tech_note09186a0080094781.shtml#appc)
Change your cable to cross-over cable and then you should be able to change the speed and duplex.
HTH,
___
Edison.
01-15-2008 07:02 AM
Edison did they have auto-mdix back on the 3550's ? Not sure they did .
01-16-2008 11:53 AM
Glen, you are right.
01-16-2008 03:41 PM
I have never seen something like this . I would make sure the trunking parameters are exactly alike on both ends . Usuaully though you should get at least a link light , are the patches ok ? When you set it as auto does it autonegotiate 100/full ?
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide