Fluctuating Throughput

scbbni · ‎12-07-2005

I’m having intermittent latency problems with one of my Catalyst 4506 (Sup IV engine) multilayer switches. The device is configured as a router. I’m using a bandwidth tester to measure bandwidth from my laptop to a remote device positioned on the network. I'm seeing large fluctuations in throughput when directly connected to it. On every point in my network I’ve got consistent 90Mbps throughput except on this switch. When physically connected to the switch it fluctuates between 100Kbps and 30Mbps (less than half of average bandwidth everywhere else on the network).

I’ve physically connected the test equipment to three different 10/100/1000 blades on the switch and have placed my laptop in all three of the VLANs assigned to it but do not see any change.

When I connect my laptop to any switch directly connected to the Catalyst 4506 and test through the 4506 to the remote end-device I get consistent 90Mbps.

I’ve rebooted the switch but still have the same problem. CPU utilization is only 12% and has a lot of free memory for processing tasks.

Has anyone else seen this problem or know what it might be?

Thanks.

glen.grant · ‎12-07-2005

The only thing I can think of is maybe your nic is not negotiating with 4506 cards correctly. Make sure your nic setting matches whatever the 4506 port settings are , if the 4506 setting is auto your nic must be auto, if port is hardcoded then hardcode your nic to match the port setting. You can not have one end as auto and the other hardcoded .

scbbni · ‎12-08-2005

Both the tester and switchport were hardcoded for 100/full. Ports are not taking errors.

I rebooted the switch last night but still have the same problem.