topic Re: SSH Port redirection in Operating System - HP-UX

SSH Port redirection

Gary Price — Sat, 17 May 2003 11:55:38 GMT

I'm currently using ssh to forward http over a secure channel. However, ssh seems to listen on all interfaces when using the command below.

ssh -b Local_IP -N -L 80:remote_server:80 -f -g

The problem is I run several interfaces on the server and only wish for SSH to listen on a single interface. I've also tried remote forwarding but could only get ssh to listen on the local loopback.

HP-UX Secure Shell 3.1
HP-UX 11.11

Thanks,
Gary

Re: SSH Port redirection

Paula J Frazer-Campbell — Sat, 17 May 2003 12:03:32 GMT

Gary

This might help:-

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x44a03a1c04ffd61190050090279cd0f9,00.html

Paula

Re: SSH Port redirection

Bill Douglass — Sun, 18 May 2003 04:59:47 GMT

Just to clarify Paula's answer, the ssh_config manpage states:

GatewayPorts

Specifies whether remote hosts are allowed to connect to local forwarded ports. By default, ssh binds local port forwardings to the loopback address. This prevents other remote hosts from connecting to forwarded ports. GatewayPorts can be used to
specify that ssh should bind local port forwardings to the
wildcard address, thus lowing remote hosts to connect to forwarded ports. The argument must be ``yes'' or ``no''. The default is ``no''.

It seems that the current version os openssh, at least, does not allow you to specify the interface that remote hosts can connect to for port forwarding.

The -b option only tells openssh what interface to use when connecting to remotehost.

Using a tool like ipfilter, you can control what interface or ip address is allowed to receive inbound traffic on port 80, which ssh will then forward to your remote host.