A friend recently pointed this method out to me, and it's too handy not to pass on.<br>
<br>
I've got two networks (work and home) that severly limit inbound
connections (nat at home, restrictive firewall/IDS/etc at work). On
both ends, there are "bastion" hosts that allow inbound ssh. From that
host, I can connect on to anywhere on the network. Works fine, but can
be a PITA when I want to say rsync a copy of the x-org debs from the
mirror at work to the fileserver at home. I used to have a nasty ad-hoc
port-forwarding mess. Nasty. That and ssh listening on odd ports on my
nat box to reach inside hosts... hard to maintain, didn't always work
nice with scp/rsync/X/etc. Enter the OpenSSH ProxyCommand option.... I
put the stanzas below into ~/.ssh and life is good. It assumes you've
got netcat installed on your bastion host, and I think the -q option to
nc might be a debian-ism, but oh so nice.<br>
<br>
<br>
Host *.work.gov<br>
ProxyCommand ssh -a -x ip.of.bastion.host nc -q 1 %h %p<br>
Protocol 2<br>
Cipher blowfish-cbc<br>
Compression yes<br>
Ciphers aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc<br>
EscapeChar ~<br>
Host *.home.org<br>
ProxyCommand ssh -a -x ip.of.home.gateway nc -q 1 %h %p<br>
Protocol 2<br>
Cipher blowfish-cbc<br>
Compression yes<br>
Ciphers aes128-cbc,3des-cbc,blowfish-cbc,cast128-cbc,arcfour,aes192-cbc,aes256-cbc<br>
EscapeChar ~<br>
<br>