General discussion


NIC changes speed

By FlatFive ·
I have an IBM e series model 240 with a built-in IBM fault tolerance 10/100 NIC. I'm running 2k server, SP4, all the updates installed. Generally, it runs great. In fact, I have two, one running 2k server as a domain controller, backup server (Veritas , file server. The other is a terminal server, same version and updates.
My problem is this:
On my DC server, the NIC likes to drop from 100mbps to 10mbps. It does this regularly, usually overnight. I suspect it is happening during backup. It runs a full local backup and uses the agent for a full backup of the TS and another machine, running 2k pro and a Spam filter product.
I have changed switches, from a cheap D-Link to a Cisco Catalyst 3550. I thought that auto-negotiate might be the problem. I have tried auto and forced settings with the Cisco switch and in either case, it starts off at 100 and drops to 10 within one to two days. This problem never occurs on the Terminal server with identical hardware.

Has anyone exerienced a similar problem? If so, have you had any success in solving it? This has vexed me for months and I feel like I am running out of things to try. While not a huge problem, it is a real nuisance and does impact perfomance for clients.


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by p.j.hutchison In reply to NIC changes speed

We have solved this problem by setting 100/Full Duplex on the on card and on the Switch as well and NOT allow them to auto-negotiate.

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by FlatFive In reply to

As I said, I tried forced settings (card and switch) and same result. This might be the weirdest part of the situation, because the NIC setup will say it's set to 100/full, but it shows as running at 10! Remember, this is after a day or two. It starts out showing that it's running at 100.

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by BFilmFan In reply to NIC changes speed

I would recommend a call to IBM and CISCO to see if this might be a known issue. I have seen NICs that would refuse to stay at 100/Full even when they are set. A couple of times I had to do a BIOS upgrade to resolve the issue.

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by sgt_shultz In reply to NIC changes speed

i would be talking to ibm or trying another nic also. otherwise all i can offer is that all other things equal how are the collisions looking that time of day. cable is fine, yes?

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