LAN, Switching and Routing: No link between fiber converter and Catalyst 6500, works with Router 730

Greetings all

I have tried to find an answer to and issue like this before but
without success.
I've tried for some day now to get a fiber connection between an
IMCnetworks MM850 GigabitTP<->Fiber converter up and running. The fiber
is on my end connected to a SX SPF. When I connect the cable and enable
the interface I get a LinkUp light on the media converter but no link
on my Cat6500. I've tried different autodetect, negotiation and speed
settings but nothing works. I've also tried different SPFs and switched
cables.
As a final solution I plugged the fiber cable into our 7301 router,
bypassing our Cat6500. After I set the port to "no negotiate auto" the
link went up on the 7301.

How can the same cable and same SPF work on the 7301 but not on my
Cat6500? Is there some setting I'm missing here?

Regards
Fredrik Hofgren

 

Hi Frederick,

That certainly sounds like the problem, however one thing seems
obvious to me, the Device you are trying to connect appears to NOT be
doing any negotiation. This means you MUST set the Cisco device to not
even ATTEMPT to autonegotiate, the settings should match between ends
EXACTLY, so that the Cisco device does not even try to autonegotiate.


From you comments about the 7301 connection working I would also check
the Auto MDX (X-over), however I have seen this work both ways in no
negotiate scenarios so I guess it depends on the exact H/W involved.

Its not much but I hope it helps.................pk.