port forwarding

Florin Andrei fandrei at mail.rds.ro
Fri Apr 28 19:40:15 EST 2000

	Ok, so this is not a users-list, but i really don't know where to ask.
Maybe a future openssh-unix-users at mindrot.org will take this kind of
problems... :-)

	So, i'm trying to forward a POP3 connection over a SSH tunnel, using
openssh-1.2.3 both on server and on client. My host is atlanta.rds.ro and
the mailserver is mail.rds.ro. I did like this:

ssh -L 110:mail.rds.ro:110 mail.rds.ro

	After authenticating myself on mail.rds.ro, the 110 port appeared as open
on localhost, but it forwarded requests to mail.rds.ro - this was ok.
	The sniffer revealed that the traffic was done between my host and
mail.rds.ro:22 - this meaning that POP-over-SSH was actually working. Ok
'till now...

	After that, i tryed this:

ssh -L 110:mail.rds.ro:110 localhost

	110 was opened again on my machine, forwarding the requests to
mail.rds.ro. Ok again.
	But... after sniffing the interface, i saw that, this time, the packets
were sent to mail.rds.ro:110, not to mail.rds.ro:22 so this wasn't actually
POP3 over SSH! The only difference was that, this time, i wasn't
authenticated on the mail server itself, but on localhost.

	The problem is that i want to forward POP3 over SSH, but not authenticate
myself into a shell account on the mailserver. I don't wanna this, because
we have here very strict shell policy, and we don't wanna leave accounts
with shell access enabled.

	How can i obtain a true pop-over-ssh connection without using shell access
on the server?

	Sorry if i was too off-topic.

Florin Andrei
mailto:florin at linuxstart.com	http://members.linuxstart.com/~florin/
tel: +40-93-261162

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