Firewall Wizards mailing list archives
FTP-Data connections?
From: fernando_montenegro () hp com
Date: Wed, 10 Nov 1999 11:17:33 -0500
Hi everyone! I've just come across a curious problem, and I wonder if you guys can help me... When connecting to a remote FTP server (I've tried ftp.microsoft.com, ftp.redhat.com and ftp.cdrom.com, among others) from a command-line FTP client (running on Linux), the standard FTP control connection works fine, but the data connection (on 20/tcp) never gets established. The weird thing is that the control connection reports "No route to host" after it fails to connect back to my client on a high port. No traffic ever reaches the local LAN or the connecting router. Passive mode doesn't work either. This is happening off one particular ISP, who assures me they have no filtering whatsover installed. When testing off a different ISP, things work out fine (data connection gets established and transfers work without a glitch). Can anyone shed any light on what might be causing this? If there was no route back, the control connection wouldn't be established, would it? I am wondering if the ISP didn't add a stateful packet filter somewhere up the route and forgot to mention it to us. Any other ideas? ObFirewalls: When this finally works, the ISP link on our end will be protected with a Firewall. Before making by job harder by adding the firewall into the equation, I'm testing the simple stuff first... Thanks! Cheers, Fernando -- Fernando da Silveira Montenegro Hewlett-Packard Brasil HP Consulting - Internet Security Al. Rio Negro, 750 - Alphaville mailto:fernando_montenegro () hp com Barueri, SP - Brazil 06454-000 voice: +55-11-7297-4351 #include <disclaimer.h>
Current thread:
- FTP-Data connections? fernando_montenegro (Nov 10)
- Re: FTP-Data connections? Mikael Olsson (Nov 14)
- Re: FTP-Data connections? Saravana Ram (Nov 14)
- <Possible follow-ups>
- Re: FTP-Data connections? Robert Graham (Nov 14)
- RE: FTP-Data connections? fernando_montenegro (Nov 14)