|
On Tue, 6 Aug 2002, Joe Lewis wrote: > > Remote Remote Local > Address Port Port Idle Time State > 66.xxx.yyy.zzz 21 6340 000:00:03 Established > 192.168.254.121 1234 6341 000:00:01 SYN-sent > > For some reason, the AS/400 is trying to access address 192.168.254.121, > which happens to be the Win2K private address on their side of thier > Firewall/NAT. Of course, the connection never completes and times out. > > Why is their private address come up and how can I get the PASV to > complete? The FTP protocol will negotiate an address & port to use for a file transfer. It does this by sending a "PORT" or "PASV" command. (depending on whether you are using standard or passive mode) For example, if the client sends PASV, the server will reply with: 227 Entering Passive Mode (192,168,254,121,4,210) That response tells the client that it needs to make a connection to the IP address 192.168.254.121 and on port 1234 (4 x 256 + 210 = 1234) The problem is that the server thinks it's addr is 192.168.254.121, but your system thinks it's addr is 66.xxx.yyy.zzz. This is because NAT is changing the IP addresses in the packet header, but is not checking for the FTP-specific PORT or PASV commands. Actually, I'm assuming it's NAT because you said "NAT" in your message. It's either a NAT that doesn't understand the FTP protocol, or it's a proxy that's proxying port 21, but doesn't understand the FTP protocol. In either case, you'd have the same error. If I'm correct in my diagnosis, then this isn't an AS/400 specific error. It should happen with any FTP client that connects to that IP address, likewise it won't only fail on PUT/GET but will also fail on LS or DIR commands. The specific fix will depend on their environment. Either the NAT/proxy is misconfigured, or it will need to be upgraded or something like that :) They'll need to contact whomever set up the NAT/Proxy for details. Good Luck!
As an Amazon Associate we earn from qualifying purchases.
This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].
Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.