Tengig 3750

[the-lebowski]

Quick question, I setup an iSCSI evironment using a 3750E with 2 Tengig ports.  I connected the SAN to Te1/1/1 yesterday and all worked fine.  Today Te1/1/1 was down and wouldn't come up.  So I moved the SFP to Te1/1/2 and it came up without fail.

Te1/1/1                unassigned      YES unset  down                  down   
Te1/1/2                unassigned      YES unset  up                    up

interface TenGigabitEthernet1/1/1
switchport access vlan 1099
spanning-tree portfast
!
interface TenGigabitEthernet1/1/2
switchport access vlan 1099
spanning-tree portfast

What could be the problem?

[Leo Laohoo]

Check your logs.  It should tell you why the interface went down.  Another is to enter the command "sh interface status error".

[Marvin Rhoads]

Also note that you may need to take action to move a 3750E port out of errdisable status (if that's what happened to it). Any number of conditons can trigger such a status. As Leo noted, the log should provide the triggering event.

See the following tech note for more details:

http://www.cisco.com/en/US/tech/tk389/tk621/technologies_tech_note09186a00806cd87b.shtml#topicsubsub