Hi 16again,
Thanks for your answer. There isn't any port protection mechanism, it is by default (learn mode continous). Switch Logs are almost the same the day wich I had the problem (dates are bad):
I 10/05/12 17:27:22 ports: port 13 is now off-line
I 10/05/12 17:27:33 ports: port 13 is Blocked by STP
W 10/05/12 17:27:33 ports: port 13 PD Invalid Signature indication.
I 10/05/12 17:27:35 ports: port 13 is now on-line
W 10/05/12 17:27:46 FFI: port 13-Excessive late collisions.
W 10/05/12 17:27:46 FFI: port 13-Excessive Broadcasts. See help.
W 10/05/12 17:29:31 FFI: port 13-High collision or drop rate. See help.
I 10/05/12 17:36:41 ports: port 13 is now off-line
I 10/05/12 17:36:47 ports: port 13 is Blocked by STP
I 10/05/12 17:36:50 ports: port 13 is now on-line
W 10/05/12 17:37:02 FFI: port 13 Duplex Mismatch. Reconfig port to Full Duplex.
W 10/05/12 17:37:02 FFI: port 13-Excessive late collisions.
W 10/05/12 17:37:02 FFI: port 13-Excessive Broadcasts. See help.
I 10/05/12 17:37:48 ports: port 13 is now off-line
I 10/05/12 17:38:06 ports: port 13 is Blocked by STP
W 10/05/12 17:38:06 ports: port 13 PD Invalid Signature indication.
I 10/05/12 17:38:09 ports: port 13 is now on-line
W 10/05/12 17:38:26 FFI: port 13-Excessive late collisions.
W 10/05/12 17:38:26 FFI: port 13-Excessive Broadcasts. See help.
W 10/05/12 17:40:43 FFI: port 13-High collision or drop rate. See help
as the day I did test:
I 10/12/12 19:15:01 ports: port 3 is now off-line
I 10/12/12 19:18:35 ports: port 13 is now off-line
I 10/12/12 19:19:13 ports: port 13 is Blocked by STP
I 10/12/12 19:19:16 ports: port 13 is now on-line
W 10/12/12 19:19:24 FFI: port 13 Duplex Mismatch. Reconfig port to Full Duplex.
W 10/12/12 19:19:24 FFI: port 13-Excessive late collisions.
W 10/12/12 19:19:24 FFI: port 13-Excessive Broadcasts. See help.
I 10/12/12 19:23:23 ports: port 13 is now off-line
W 10/12/12 19:23:34 ports: port 13 PD Invalid Signature indication.
I 10/12/12 19:23:35 ports: port 13 is Blocked by STP
I 10/12/12 19:23:37 ports: port 13 is now on-line
But results are different because switch didin't learn mac addresses.
Is there any bug software that can lead to this effect or it could be cables? For me it doesn't have sense, one day switch learn mac address and another it doesn't.
Best Regards.