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Cisco and MRV equipment

I have a LAN/WAN connection using Cisco and MRV equipment. Our ISP uses MRV on the WAN side and we have Cisco across the board on the LAN side. For example:


Our Cisco equipment consists of a core 6500 and the remote sites have 3500s. All interfaces on the Cisco equipment are GBICs.

The issue we are experiencing is that periodically a connection to a remote switch will go down. Rebooting the remote switch will not fix this. It is necessary to unplug the fiber from the remote switch GBIC and reconnect it. MRV told me that it might be "autonegotiation." I have turned this off and it didn't help.

Any thoughts or experience with this?

Community Member

Re: Cisco and MRV equipment

Port on error disable?

I've had that problem. Seemed that in my case the port on the 6500 had a duplex/speed mismatch with the sun server (connected by fiber and gbic in one case, connected to a Nortel Core switch in an other case).

After having recieved a certain amount of corrupt packets the port is put in error disable mode by the 6500.

So the quick "workarround" was a "shutdown" of that interface (on the 6500) and a "no shutdown" which reinitiated the port and all was working again until... there number of corrupt packets was getting to high, resulting in a port disable.

So check if the port is in error-disable mode when the connection drops.

If this is the case then configure BOTH sides to use the same (static) speed and duplex.

It worked in my case.

HTH and rate if it does


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