Strange speed issues.

**mmaderich** · October 16th, 2007, 01:10 AM

We have seven servers (Power Edge 2950 - 4 GB DDR2 RAM, two Quad core Xeon CPUs, gigabit NIC), all running through gigabit switches, then all the work stations. Some workstations have gigabit NIC's, some have 10/100 NIC's. When transferring files off the servers to a workstation with a gigabit NIC, it's blazing fast, like a 16 MB file is done instantly (like it should be). If you transfer a file off the servers to a workstation with a 10/100 NIC, it's incredibly slow, the same 16 MB file takes 9 minutes to copy. A 16 MB file should never take 9 minutes to copy over a 10/100. I hooked a little 8 port 10/100 to my work station and a web server I have under my desk and transfered a 16 MB file over it, while still connected to the rest of the network, to my workstation, copied in about three seconds. For the life of us, we can't figure out why it takes 9 minutes to copy a 16 MB from the servers (even if no one else is on the network but myself or my coworker). Anyone have any ideas?

**NooNoo** · October 16th, 2007, 03:48 AM

Welcome to Windrivers mmaderich
Off the top of my head I would say one of the following
Bad patch cable somewhere
Nics not autosensing and defaulting to 10mb
Nics not in duplex mode
Lots of collisions (is this a fully switched network?)
Failing port(s) on a switch
Managed switch configuration not quite right.

**mmaderich** · October 16th, 2007, 07:29 AM

NooNoo -

I appreciate you getting back to me, it's much appreciated. We just replaced all the patch cables last night, as well as put in brand new gigabit switches. We'ved tried forcing NICs to do 100 Full Duplex (or Half), but have had the same issues. Also, our switches are unmanaged switches. Any other suggestions would be greatly appreciated.

**Niclo Iste** · October 16th, 2007, 10:11 AM

Hmmm intriguing we're having the same issues in our office...... PBTG wouldn't mean anything to you would it?

**mmaderich** · October 16th, 2007, 10:15 AM

Originally Posted by Niclo Iste

Hmmm intriguing we're having the same issues in our office...... PBTG wouldn't mean anything to you would it?

Phoenix Business Technologies Group, Inc? (Only guessing that due to a quick google search, but honestly, yeah, doesn't mean anything to me, but hopefully one of us gets this problem sovled.)

**mmaderich** · October 16th, 2007, 10:19 AM

Also, just tested something. I booted up the one workstation using an Ubuntu live CD, and the connection is fantastic over the 10/100, transfered 16 MB in about 1.5 - 2 seconds, yet if I reboot it back to Windows, it's slow as all get out again.

**Niclo Iste** · October 16th, 2007, 10:30 AM

Well just a notion for something for you to look at. Though I find this strangely odd that it would be the cause. Our senior techs claim our speed drops are from people listening to streaming music and watching streaming videos. I don't see how this could be slowing down a network like ours if only 40% of our staff at most uses it at once and on average 15% uses the streaming media continuously. My home network fairs better on traffic and it's just a 10/100 on DSL. However I'm not here to complain about my companies views. Just take a look at your traffic, see if the streaming media may be a culprit.

**mmaderich** · October 16th, 2007, 10:50 AM

Originally Posted by Niclo Iste

Well just a notion for something for you to look at. Though I find this strangely odd that it would be the cause. Our senior techs claim our speed drops are from people listening to streaming music and watching streaming videos. I don't see how this could be slowing down a network like ours if only 40% of our staff at most uses it at once and on average 15% uses the streaming media continuously. My home network fairs better on traffic and it's just a 10/100 on DSL. However I'm not here to complain about my companies views. Just take a look at your traffic, see if the streaming media may be a culprit.

I had actually suggested the same thing last night, then it occured to us that the only people connected to the network where he and I, and neither of us were streaming anything at all. I wish it were that simple. But thanks for the suggestion.

**NooNoo** · October 22nd, 2007, 05:53 AM

Well you have something restricting the flow to 10mb... thought about installing a network monitor ... like this one?

**Niclo Iste** · October 22nd, 2007, 09:24 AM

Do you use firefox?

**ebutler79** · October 23rd, 2007, 10:41 AM

We are having the same issue with a 2950 I put in. I have workstations that are connected to a 100 mb switch that work ok. Plug the same workstations into the Gb switch and the speed goes to 10kb throughput or so.

The only workaround I have found is putting in a new Gigabit NIC into the older pcs. Does you 2950 have the broadcom Gigabit cards in them or the intel?

**NooNoo** · October 24th, 2007, 06:24 AM

Welcome to Windrivers ebutler79

Interesting, that would imply that the switch is unable to negotiate with the card at 100mbs and just defaults to the slowest speed.

**ebutler79** · October 24th, 2007, 07:12 AM

I would have maybe thought that as well but transferrs to other servers on the core switch the 2950 is on are very good. Its only to the PowerEdge 2950 that I am having problems with. That was the reason I am curious as to what NIC the OP is using in his server.

I have been at networking several years and this is a strangest issue I can remember in a good while.

Thanks
Erik

**NooNoo** · October 24th, 2007, 07:22 AM

Have you sniffed the packets... packet errors, size etc?

**PBase001** · October 24th, 2007, 07:50 AM

Just curious what brand of switches are you using?

How many NIC's on the server and if there are two which is typical for current servers are they both connected to your network?