I'm using gnatbox lite, and have found one ftp site that is very slow when
going through gnatbox. If I take the gnatbox out of the path, it's very
fast. I'm using version 3.0.3, but had the same problem in 3.0.1. I'm
looking for suggestions of what to try next.
Details: I've got a couple of NT4 boxes on my private network, and a cable
network on the external network. There are two ftp sites on the cable
network that are used as test download areas. They are provided by the cable
provider (roadrunner), so are known to be on directly on my "local" cable
network.
Downloading a large file from site 1 gives me about 300 KB/s transfer rates.
Downloading from site 2 gives me 20 KB/s transfer rates. The site 2
transfers are very burst-y; it will pump a bunch of bytes across, then pause
for a second or several, then pump across another burst.
If I connect one of my NT boxes directly to the cable modem (bypassing
gnatbox), I get 350 KB/s from site 1, and 450 from site 2! I've repeated
this experiment at various times of day, and it's quite repeatable; it's not
a problem with the ftp sites themselves.
The two sites are different machines and even different OS's. I know that
site 2 sends a bunch of IDENT requests to my box during the transfer, while
site 1 does not. When I first noticed this problem, I had IDENT disabled in
my filters, and could see the filter messages in my gnatbox logs. I thought
this might be the problem, and re-enabled IDENT in my filters, so they are
now being answered by the gnatbox mini-IDENT server, and I no longer see
messages in the logs. This had no effect on thruput, however.
The logs show nothing exciting, and the same for both sites. I can see the
OPEN TCP on port 21 to initiate the transfer, and then the OPEN FTP PASV TCP
on a high numbered port.
Any suggestions for what is going on, or what I can do to diagnose if
further?
TIA,
Don
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