Actually I know the cables are OK because I have used the intel drivers to validate the cables. All indications (lights on cards, and switch), along with diagnostics in the drivers, all indicate gigabit full duplex
I am not using a managed switch, so I can't get any info from it.
I have also used iPerf which shows me similar results.
-Scott
----- Original Message -----
From: "Marc Luethi" <netztier@xxxxxxxxxx>
To: "Community support list for Wireshark" <wireshark-users@xxxxxxxxxxxxx>
Cc: "Scott Chapman" <WireShark@xxxxxxxxxxxxxxxxx>
Sent: Saturday, March 7, 2009 4:14:13 AM GMT -05:00 US/Canada Eastern
Subject: Re: [Wireshark-users] Slow gigabit network
On Fri, 2009-03-06 at 21:29 -0500, Scott Chapman wrote:
> So, the problem I have is that I get about 12-14MB/sec when I copy
> files.
Might be protocol overhead, as (almost) usual. Yet, assuming that the
cabling is okay from the fact alone that both cards connect at 1Gbps is
wrong. There might still be CRC errors (and hence packet loss and TCP
retransmissions), or flow control might be stepping in:
http://www.smallnetbuilder.com/content/view/30212/54/
If the switch is a managed one, have a good look at each port counter,
or see if you can undig some of those counters from the depths of your
NIC's driver. Wireshark might even be able to show flow control pause
frames being sent or received by the system it runs on.
Get a Windows or Java version of iPerf or jPerf, and use it to shove
data from box to box. Here's how - same procedure for Linux and Windows.
http://ubuntuforums.org/showpost.php?p=6758444&postcount=7
http://ubuntuforums.org/showpost.php?p=6522634&postcount=4
If you get reasonable throughput numbers here, you can safely assume
that the IP stacks and storage I/O systems are in good shape.
Then you can start to deep into the analysis of the involved protocols
like CIFS, NetBIOS-over-IP or NFS.
regards
Marc
