[svlug] is a DS3 to fast for stock Linux RH6.2?

[Daevid Vincent]

I have a server that was doing just fine on a wimpy 768/384k DSL line by
NWLink. We got a DS3 line finally, and when I switch the IP and cable over
to it, eth0 drops whenever someone tries to send a large amount of data into
the box from WITHIN our building after the first "chunk". This is around
100KB; I've seen as high as 500KB and as low as 80KB.

If I transfer a huge file in from OUTSIDE (i.e. another server on the
internet), it seems to work fine. At first I thought it was wu-ftpd (wild
guess), but I tried NcFTPd and same problem. I disabled all ftp services and
used a web based PHP upload form, and same thing occurs.

the box doesn't hang or anything, it just 'drops' it's connection. If I
simply type "ifdown eth0; ifup eth0", it's online again no problem, but I
have to keep doing it every time, and from within the server room, since I
can't do it remotely without a network connection.

If we switch the cable back to the NWLink DSL line and IP's, transfers work
fine like they did before. We have other non-Linux servers on the same DS3
switch/IP network that have no problems with the ftp transfers.

The box is RedHat v6.2. PIII-800, 256MB RAM, 10/100 Ethernet card, 100Mbs
switch,

Anyone have ideas on what it could be? Is there some buffers or something
that I need to tweak? I don't notice anything in the /var/log related to
ftp. Is there a specific log file I should look at? I also notice my
/var/log/xferlog is always empty.

Daevid