topic Re: ftp / firewall in Operating System - HP-UX

ftp / firewall

Keith Floyd — Mon, 11 Sep 2000 13:49:37 GMT

Hi

I have problerms with ftp and going throufg a firewall.

Using netstat -p tcp what pertinent info can I gleam from this, that may help me diagnose the problem

Thanks

Keith

Re: ftp / firewall

Mike McKinlay — Mon, 11 Sep 2000 15:15:27 GMT

What are you trying to do? Outbound FTP to a server on the other side of the firewall, or inbound FTP to a server on your side of the firewall?

Is FTP enabled on the firewall? What kinds of errors are you getting?

Re: ftp / firewall

Berlene Herren — Mon, 11 Sep 2000 16:25:18 GMT

You might need a program like Socks, available from
http://www.socks.nec.com

Berlene

Re: ftp / firewall

Kofi ARTHIABAH — Mon, 11 Sep 2000 17:21:09 GMT

What firewall are you using. It sounds like you are having difficulties with PASV mode transfers...

Re: ftp / firewall

Rick Garland — Mon, 11 Sep 2000 20:41:04 GMT

The firewall may be set to block the ftp traffic. Can you check to see if the ftp port is blocked? If so, you may want to look into the socks solution that Berlene mentioned.

Re: ftp / firewall

ESC Team — Mon, 11 Sep 2000 20:53:06 GMT

It is possible that the port FTP uses
(usually 21) is closed. You will need to
contact the network administrator for your
site and check that this port is open. To
check that the FTP service is functioning
correctly, try connecting to another machine
on the same subnet. If this works, then
check that the firewall port is open.

Re: ftp / firewall

Keith Floyd — Tue, 12 Sep 2000 09:04:32 GMT

thanks so far more info

ftp works - is constantly cron'd to send/rec. My issue is that quite often ftp seems to lock up.
I wonder whether it's due to TCP timeout etc, hence I wanted to interpret the netstat -p

thanks

Keith

Re: ftp / firewall

Andrew_4 — Tue, 12 Sep 2000 20:55:36 GMT

You might need to try doing a trace on the ftp protocol, between the two hosts you're ftp'ing (This is done by filter by IP address). You can do this via the nettl command.

It can be a little complex, so you're best to read the man page.

Andrew

Re: ftp / firewall

Kofi ARTHIABAH — Wed, 13 Sep 2000 00:28:26 GMT

Keith,
If your ftp files are really really large then you could run to the TCP timeout problem causing it to fail. If that is the case, you would have to fix the TCP timeout on the firewall itself. BTW what firewall are you running? is it a proxy, or packet filter, or stateful?