iperf question

Don't know. You didn't post the test results.

Yep. It's the speed from the client to the server. However, you can control the direction with various options. Try Iperf -h for a list.

These might be useful: -d, --dualtest Do a bidirectional test simultaneously -r, --tradeoff Do a bidirectional test individually -P, --parallel # number of parallel client threads to run

Caught me, I was trying to decide whatever result it presented referred to what direction relative to one of the hosts to help me decide what to look at.

I am troubleshooting a general speed issue and isolated it to the wired LAN speed from the server which is highly asymmetrical. iperf reported

300 kbit in one direction and 70 Mbit in the other direction just working on the wired 100 Mbit LAN using my notebook and also another server for testing. Updating NIC drivers and turning off scalable networking brought the low speed up to 5 Mbit which is still lame. The server has a GigE card and there is a 100Mbit unmanaged switch . Forcing link speed on the server to various auto/full/half didn't make much difference. I suggested they replace the switch with a GigE switch which makes sense because there are two servers with GigE capability. I think the server NIC just doesn't like talking to the switch. The server had a second onboard NIC and I switched to it and also tried various switch ports and it didn't make a difference.

I have tried switches like -d but it simply gives both results leaving you to wonder which is what.

Good question, but an obvious answer, which you already supplied.

Hint: If you have a problem that needs solving, then please supply:

1. What problem are you trying to solve?
2. What hardware and software do you have to work with?
3. What have you done so far and what happened?

I've seen this literally dozens of times. Lots of causes ranging from bad NIC's, NWAY negotiation failure, CAT5 cable wiring problems, connector failure, media converter failure, hung ethernet switch, full/half duplex problems at the NIC, overly busy server, etc. I'm going to be my usual obnoxious self and not offer any more until you disclose what hardware you're working with and how you're doing the iperf testing (specific command line incantations). That's because UDP and TCP testing often yield very different results.

Wrong on both numbers. I consistently get 90-95Mbits/sec from a

10/100baseT ethernet switch. Obviously, the 300Kbit/sec is also wrong. You might try removing the intermediate switch, grab some known good CAT5 cables, and go directly from the "other" server and your notebook. Also, check the settings on the ethernet port on both machines. You can sorta create the problem by having one set to full duplex, and the other to half duplex.

Replace the cables, test server, and/or switch, one at a time, until the problem evaporates. It's called troubleshooting by substitution.

It shouldn't make any difference. Since updating the driver has such a derastic effect, you might consider the possibility that the unspecificed device with the NIC card is having a bad day. It could be busy from some errant process. It could have a bad NIC.

Any particular model number GigE card?

Maker and model? Yeah, I know I'm demand a lot by asking you to supply such details. However, there are some boxes out there that are little better than defective.

Forcing it where? At the server? At the laptop? With a mechanical switch on your unspecified unmanaged switch?

Yeah, that makes sense if the intermediate wiring is 1000baseT qualified? What manner of cable and how long?

I also don't like talking to people and devices that I know nothing about.

Try a 2nd laptop in place of the server. See if the unspecified model GigE switch is the problem.

If you have both directions, does it really matter which is which as long as they're the same? Methinks you're avoiding the problem.

Your question has absolutely nothing to do with wireless or wireless internet. You might consider asking the same question (with the missing details supplied) in one of the networking newsgroups.

just vanilla TCP using iperf -c

Agree, it is a remote location and I simply ran out of time because of an ice storm that was closing in. I replaced the cables and have a GigE switch on order as a replacement.

Its a Dell Poweredge 1950 with dual onboard Broadcom Net Extreme II NICs. I configured the other NIC and switched over to it but there was no difference.

It is a D-link something (can't read my notes)

At the server.

The switch is right above the servers so only short patch cables are needed.

Yes, thank you much for your interest and suggestions. I didn't go into big details initially because I just wanted to understand what iperf was telling me.