[c-nsp] What happens during the "shutdown" and "no shutdown" to a 1000BASE-LX10 port

[Martin T]

I have a following connection:

WS-C2960G-24TC-L[Gi0/24] <-> [1/8]Brocade_switch


..and today after few flaps between the two switches because of the
cabling works, the ports in both switches came up:

Gi0/24    -> Brocade  connected    trunk      a-full a-1000 1000BaseLX SFP

..and according to "show interfaces Gi0/24 switchport", the I Gi0/24
seemed to be working fine. However, I could not see any MAC addresses
on VLAN's allowed to this trunk port. Finally I did "shutdown" and "no
shutdown" to the Gi0/24 port and all of the sudden, I saw MAC
addresses on VLAN's. There were no differences in "show int status" or
"show int Gi0/24" before and after the "shutdown" and "no shutdown". I
don't manage the Brocade switch. SFP in Gi0/24 is made by Finisar.
There is nothing interesting in the log of the Cisco switch.

I'm just curious, what might happened and how did the "shutdown"/"no
shutdown" improve the situation? Or is it impossible to analyse such
problems(afterwards)?


regards,
martin