Physical layer issue?

[jorgeborges]

I have a Cisco 4506 (CS-02) that connects to a Cisco 2960G (AS-05).

A few days ago, they lost connectivity to each other. We found out that the fiber link between them had been turned off (this is handled by an entirely different department/company).

It has been turned back on and "verified", but there is still no connectivity between the switches.

There is no link light on either end. I can see the light coming out of the fiber on the AS-05 side; I cannot see the light coming out of the CS-02 side.

I have replaced the GBICs/SFPs several times on both sides and have replaced the 2960 switch, but the issue doesn't go away.

Does this sound like an issue with one of the switches or with the fiber between them?

[Leo Laohoo · Accepted solution]

1.  The port(s) may have gone into an error-disable state.  Console into both ends and check. 

2.  Swap the patch leads around (one end only).  

3.  Verify the fibre is terminated correctly.  People have been known to patch the WRONG ports.

[jorgeborges]

The port on AS-05 did go into error-disable mode.

I logged in via console cable and did a "shut" followed by a "no shut" on that port, it now says "disconnected".

[Leo Laohoo]

We found out that the fiber link between them had been turned off (this is handled by an entirely different department/company).

Someone needs to "eyeball" what they've fixed.  Someone may have patched the cables to the wrong pair.

Do you have a "visible light" probe?