Re: FTP very slow send but fast get

From: Chris W (chrisw3_at_cox.net)
Date: 08/12/03 

Date: Tue, 12 Aug 2003 15:37:57 -0500

Dave Uhring wrote:

> Does the switch have indicator lights? I don't see any way to determine
> the media setting for a Linux ethernet interface from the shell prompt.
>
> What kind of NICs are you using, both Windows and Linux?

They are both 3com nic's the one in the windows machine is a 3C905B-tx the one in
the linux machine is a 3C905C. I also have an old 10 mbit generic no name NE2000
card in that machine that I'm not using. Just for the heck of it I hooked that
nic up to the switch to see what would happen. I used ftp to send and get a 100+
Mb file and the send transferred at 264.56Kbytes/sec while the get transferred at
668.82Kbytes/sec. I was also watching a network performance monitor and the send
graph is much more jagged than the receive but still not as jagged as with the 100
mbit card. I also changed the card in the windows machine to full duplex and then
half duplex with no change in the results. It also seems that the longer the
transfer goes on the send the more jagged the graph gets. One time the send was
going along at its normally slow speed when about 80 MB into the transfer it
slowed down to a ridiculous crawl, I'm talking slow modem speeds. I have no ideas
at this point. The NE2000 card has no overruns like the 3com card does at this
point with about 300 mb sent and received. As a side note the NE2000 is eth0 and
the 3com is eth1. If there is no cable in the NE2000 I have to shut down eth0
before I can get a network connection on eth1. I have no idea why that is either. 

--
Chris W
"They that can give up essential liberty
to obtain a little temporary safety
deserve neither liberty nor safety."
-- Benjamin Franklin, 1759 Historical Review of Pennsylvania

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