[clug] Why is my SSH port forwarding failing all of a sudden?
Tony Lewis <tony@...
2016-02-01 10:46:13 GMT
I SSH to my server, and use local port forwarding to reach in to other
servers. It was working a treat until today.
Nothing changed on the server or client configs, though the clients
(Cygwin) did upgrade from
OpenSSH_7.1p1, OpenSSL 1.0.2d (XX) Aug 2015
OpenSSH_7.1p2, OpenSSL 1.0.2f 28 Jan 2016
I tried downgrading but can't go back to earlier than OpenSSH 1.0.2e. I
am having the same problem on my Linux desktop also.
The problem is at the tunnel server. In /var/log/auth.log I see:
Received request to connect to host blah.domain port 22, but the
request was denied.
Googlage indicates proposed solutions that involve enabling port
forwarding. But I have no AllowTcpForwarding directive, and the default
is "yes". There are no PermitOpen directives (though I tried them) and
the result is the same with or without the PermitTunnel directive.
The authorized_keys file contains only keys, no restrictions (e.g. no
I know the problem is with the server, because it makes no attempt on
the network to establish a connection to my destination server.
Something in the server is administratively blocking my port forwarding.