I use reserved IP under NAT and try to connect a remote Zope FTP server. The connection can't be established. But if I am not under NAT and use a legal public IP, the ftp connection is very well. Is there any solution?
"zope" == zope <zope@suse99.cyberworksolution.com> writes:
zope> I use reserved IP under NAT and try to connect a remote Zope FTP zope> server. The connection can't be established. But if I am not under zope> NAT and use a legal public IP, the ftp connection is very well. zope> Is there any solution? Try configuring your FTP client to use passive mode (PASV). -- Bob ------------------------------------------------------------------------ Bob Finch email: bob@nas.com Network Access Services, Inc. voice: (360) 733-9279 P.O. Box 28085 fax: (360) 676-0345 Bellingham, WA 98228-0085 WWW: http://www.nas.com/
Bob Finch wrote:
Try configuring your FTP client to use passive mode (PASV).
Now is this because Zope is doing something silyl or because FTP behind NAT is like SSH, and must be passive regardless of the FTP server you're using? cheers, Chris
"Chris" == Chris Withers <chrisw@nipltd.com> writes:
Chris> Bob Finch wrote: >> >> Try configuring your FTP client to use passive mode (PASV). Chris> Now is this because Zope is doing something silyl or Chris> because FTP behind NAT is like SSH, and must be passive Chris> regardless of the FTP server you're using? This is an issue with FTP and NAT in general. PASV also helps if the client has a firewall or packet filter that denies incoming TCP connections. When transferring a file in the default (active) mode, the FTP server opens a TCP connection back to the client. Some NAT implementations aren't smart enough to be able to route this incoming connection to the correct internal host. Passive FTP avoids this problem by doing outgoing connections from the client for the data transfer. During a file transfer, the server instead waits for an incoming connection from the client. No more incoming TCP connections and NAT is happy :-) -- Bob
participants (3)
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Bob Finch -
Chris Withers -
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