Fiber problems 2900, 2650

[Lasse_e]

I have one 2900-48G (J9050A), three 2650 (J4899B) and one 2626, all switches are equipped with Gigabit-SX-LC Mini-GBIC (J4858B).

The fibers are 62.5/125, also the LC-SC patch-cables.

All the GBIC’s shows up as enabled.

The 2900 switch is the backbone and equipped with 4 GBIC’s.

All the switches are running the latest software.

And now to the problem:

One of the links comes up without problem (30 meters(100 ft.)), but the longer links don’t come up. The rest of the fibers are longer, about 50 meters (165 ft.) and 100 meters (330 ft.) and don’t come up.

The fiber is not faulty, if I put back the old equipment (3com supperstack), the links goes up. And if I have one of the old switches connected to my new 2900, the link comes up, and it is on the longest fibe I did this test.

Can some one tell me what I am doing wrong?

Best regards

[cenk sasmaztin · Accepted solution]

hi Lasse

please change fiber optik patchcord directional

fiber optik connection must be cross between two switch.

please see attach..

cenk

[cenk sasmaztin]

and you make all sx interface set full duplex with manuel

for example:

2900(eth-26)# speed-duplex 1000-full

other switch
2650(eth-26)# speed-duplex 1000-full

cenk

[Lars Emilsson]

Thanks you cenk, I modified the patch cables and the link comes up.