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Community Member

Cisco to UNIX problem

Hi there,

I have two Unix servers (identical) connected to a Cisco 5500 series switch on a WS-X5225R line card. Both servers are on the same VLAN so there is no routing involved. When we initiate a download from server A to server B we get around 7mb of throughput, but when we initiate it on server B to server A, we only get 3mb.

The duplex settings and speed are set to auto-negotiate on both the switch and both servers. If we try to hardcode them, we get multiple FCS errors on the switch and the server, and a throughput of only 20kb.

Any ideas would be very helpful,




Re: Cisco to UNIX problem

Might be a different setting of the port-priority. (high, low)

Community Member

Re: Cisco to UNIX problem

Both are set to high !

Re: Cisco to UNIX problem

And how about the TCP window-size on the machines. The hardware may be identical but there still remains a lot of room for differences.

A simple test might be to change over the network ports. When the same machine remains "slow" it is probably not a network-issue.

Community Member

Re: Cisco to UNIX problem

It sounds like QFE incompatibility with CatOS switches. We had the similar problem with some of our UNIX servers and old Catalyst 2948 switches and solved it by upgrading firmware to 5.5. I know that 5000 switches use the same software with 2948s. I recommend you to use BugTool for 5000 switches and QFE compatibility issues before upgrading firmware.

Hope this helps


Re: Cisco to UNIX problem

You may have a cabling issue. If you have a good cable scanner, recheck the span to see if it's still Cat5 compliant.

If you don't have a scanner, try replacing the jumpers with known good commercial cables (no hand-made). I'd start with the cable connecting Server B and work outward from there.

Good Luck


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