GBIC WS-G5486 Connectivity issue

[mastechnology]

Dear All,

We have a problem with the GBIC WS-G5486 regarding its connectivity with the

fiber cables as explained below:

The problem simply is that the link distance is less than 1 Km, and the

Fiber Optic cable is single-mode, i'm installing the GBIC both ends in

7206-VXR with NPE-G1 router, the status of the interface in one side is

up/up and the other end is down/down...!!! when i disconnect the cable from

the down/down side, the other end becomes down/down, which means that there

is some kind of signaling reaches that end.

Any Idea can help us to resolve this problem??

Thanks in advance...

Best regards,,

Magdy Hossein

[michelvanriet]

Dear,

We have similar problem between 2 switches.

A 2950 switch with a WS-G5486 module and on the other side a 2970 switch with a mini gbic module WS-G5486.

At a given moment de fiber link goes down.If I ping from the 2950 switch to the 2970 switch there is no reply,2970 is not accessible. If I to a "show intf gi0/2 "(link to the 2970) the interface is up. After a while the link is back up. If I check the logs on the 2970 the interface to the 2950 was down.but for the 2950 the interface was up.

What can cause this problem ?

the 2950 WS-G5486 module has a serialnr.AGS09110372

The 2970 WS-G5486 module has a serialnr.FNS0921D13N

So AGS and FNS is this a different manufacturer and can that create problems.

Best regards

Michel van Riet

[Georg Pauwen]

Hello,

in addition to Michel´s post, you might want to try and shut/no shut the interfaces. I had a very similar issue a while ago. Eventually I got it working by removing the GBICs, entering the interface configuration, configuring the interface for ´speed nonegotiate´ and plugging the GBIC back in.

Also, there is a hidden IOS command that might solve the problem when 3rd party GBICs are used, not sure if this is supported on the 7206:

7206#conf t

Enter configuration commands, one per line. End with CNTL/Z.

7206(config)#service unsupported-transceiver

Warning: When Cisco determines that a fault or defect can be traced to

the use of third-party transceivers installed by a customer or reseller,

then, at Cisco's discretion, Cisco may withhold support under warranty or

a Cisco support program. In the course of providing support for a Cisco

networking product Cisco may require that the end user install Cisco

transceivers if Cisco determines that removing third-party parts will

assist Cisco in diagnosing the cause of a support issue.

HTH,

GP

[michelvanriet]

Hello,

Thanks for the info.

We did a shut and no shut but the problem returns

Perhaps we have to try the "speed nonegotiate"

We are using Cisco Gbic's (cisco reseller).

But I think that we have a mixed of manufacturer on the GBIC's (see serialnr in previous mail)

Michel

[mheusinger]

Hello Magdy,

You seem to have an unidirectional link condition. I know of two reasons for that:

1) one of the fibers of the pair is broken

2) one GBIC transmitter and/or receiver is broken

Regarding option 1):

Can you swap the fibers and see whether the interface down/down swaps sides? Replace the fiber in this case.

Regarding option 2):

In case the test above reveals no change in up/up and down/down, then you might have a GBIC problem. Either the receiver on the down/down side or the transmitter on the up/up side is broken. So replace a GBIC at a time until you get the link working.

Hope this helps! Please rate all posts.

Regards, Martin