Problems with speed negotiation

Unanswered Question
Jun 20th, 2007


I'm connecting a 3560 switch to a CPE (from Alvarion). When the CPE is set to autonegotiate all the posible transmisions modes and speed, the port of the switch starts blinking green-ambar. If I force the CPE to 10 Mbps and Half, the port stops blinking and I have conectivivity.

I have other 10 siwtch with the same configuration and only two of them present the same problem.

If I perform the comand: show controllers ethernet-controller phy detail, I obtain this (see attachment)

In the section Port Status Register we can see: Error 1.

Could this be problem of the cable? What are the posible reasons why this "Error 1"?

Any help, will be appreciate.


I have this problem too.
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cisconoobie Fri, 06/22/2007 - 06:03

Run this on the port connecting to the cpe.

#test cable-diagnostics tdr interface (port)

Then run:

#show cable-diagnostics tdr interface (port)

Make sure that it says normal under pair status. I think if it runs fine under 10 half that means you may have issue with cable as its not running in full duplex.

Heres a example of one of my ports.

TDR test last run on: June 22 10:57:30

Interface Speed Local pair Pair length Remote pair Pair status

--------- ----- ---------- ------------------ ----------- --------------------

Gi1/0/1 1000M Pair A 28 +/- 4 meters Pair A Normal

Pair B 27 +/- 4 meters Pair B Normal

Pair C 28 +/- 4 meters Pair C Normal

Pair D 28 +/- 4 meters Pair D Normal

Then I would suggest making sure that the port on the cpe is mdix (auto sensing).


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