Channel Group Problems

[rlpspaden]

Hello,

Here's the issue that I could use some ideas on.  I've created a four physical port channel group using LACP and ethernet gbics from a switch I'm adding to our core 3560.  I've verified that the ports and channel groups on both ends are not shutdown and the info matches.  The switch I'm adding does in fact work (configured and tested in my office) and is properly configured for our environment... but this is my first attempt at a channel group.  The distance of the lines is 25 to 30 feet and I used straight through cables, I plan on trying crossover cables when I have some time to re-terminate the ends, but other than that I'm out of ideas.

Can anyone offer any suggestions?

Thanks

[Amit Singh]

Hi Sean,

You should be fine using straight through cable as most of the switches today support Auto-MDIX. Please check the port configuration guide for the IOS that you are running on the switches.

Please take a proper down time before you configure this in a live environment. Shut down all the ports on both the switches that you want to be as a part of the port-channel. Configure all the ports, speed/duplex, STP, trunk configuration. Use  "interface range" command if the ports are contiguous. Shut down the port-channel interface as well. Bring all the physical interface up on both the sides, after that bring the port-channel interface up on both the sides. This should bring all the interfaces fine and negotiate all the parameters of port-channel configuration.

HTH,

-amit singh

[rlpspaden]

Thanks for the response, I was thinking about it, and correct me if I'm wrong, but the auto-MDIX is only on uplink ports correct?  On one of the switches the four lines are going to normal ports... which would explain why there's no recognition/light activity of any kind.  Everything else is configured, duplex, speed, trunk, etc. the same on both ends.

[glen.grant · Accepted solution]

  That is incorrect all 3560 copper ports support mdix .  If you have no light and you are using a straight thru cable then you have probably hardcoded the speed and duplex,  auto mdix will not work unless all the ports are set as auto for speed and duplex for the connections otherwise you must use a crossover. Change all ports to auto for speed and duplex on both ends .  Between cisco devices there is little need to hardcode speeds anymore.

[rlpspaden]

That explains it, thanks. I ended up just re-terminating one set of ends to make them crossover cables.