Posts Tagged ‘Ethernet’

Gigabit auto negotiation

May 26, 2010 Leave a comment

Update: I originally posted this (on my previous blogging site) on 31 Mar 2009 and have made some updates due to broken reference links.

I ran into a strange problem while configuring an Etherchannel on a couple Cisco switches. I would set the speed and duplex on one switch to 1000 full but as soon as I set the same speed and duplex on the other switch the connection would go down. This was the first time I’ve tried to set up an Etherchannel so I incorrectly assumed it was an Etherchannel configuration mistake. After much searching I found a single sentence that indicated 1000Base-T must be set to auto/auto but no references. Luckily my colleague was looking for the same thing and sent me a link which had references and a great explanation of what happens. That link is no longer active but I’ve found others that I’ll put at the bottom of this post. Read more…

Categories: Networking Tags: ,