Cisco Support Community

3750 duplex issue

I am at thhe early stages of looking at this, and am just interested in anyone else has seen similar that may save me a little work.

We have a 3750 connected to 2600 routers. both ends are configured 100/F but the switches keep going to 100/H after a reload - it looks rather like despite the config the interface is trying to negotiate.

I need to book a session to try to bottom if the pronblem happens when the switch is up first, router up first etc to get a better handle on it, but before I put that time in has anyone seen similar?



Cisco Employee

Re: 3750 duplex issue

You are running into the following bug

PS: Remember to rate useful posts.

Re: 3750 duplex issue

Nice my vote!

Re: 3750 duplex issue

Brilliant! That looks bang on - I had only done a bug search on the IOS ver, but that is a perfect match.

Thanks for that - you have saved me at least a couple of hours there!


Community Member

Re: 3750 duplex issue

This link is dead.  Does anyone have an updated link?

I'm having this issue & need to know if there is any workaround.



Re: 3750 duplex issue

The link works fine. You need a valid cco user account to view it

You can use 'speed auto 100' at both ends or use 'shut', 'no shut'

Re: 3750 duplex issue

Might I suggest this is a reference to a bug 4 years old. If you are running an even vaguely appropriate version of software, this particular bug should not be an issue.


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