Re: openssh start another ssh session on machine b

[salva]

You can use the ProxyCommand feature of OpenSSH (requires tunnels enabled on host b and a relatively recent version of OpenSSH on the local host):

my $ssh_b = Net::OpenSSH->new($host_b, ...);
$ssh_b->error and die;
my $tunnel_cmd = $ssh_b->make_remote_command({tunnel => 1}, $host_c, 2
+2);
my $ssh_c = Net::OpenSSH->new($host_c, master_opts => [-o => "ProxyCom
+mand=$tunnel_cmd"], ...);
$ssh_c->error and die;
$ssh_c->system('ls');

Another option is to install Net::OpenSSH::Gateway available from GitHub.

my $ssh_c = Net::OpenSSH->new($host_c, gateway => { proxy => "ssh://$h
+ost_b"}, ...);

That module implements a set of strategies to forward SSH connections over different kinds of proxies including SSH gateways. It is not on CPAN because I was not happy with its internal architecture and planed to revamp it completely but unfortunately, I never got the time (or the guts) to actually do it and it has languished there. In any case I would fix any bug reported.

[jhuijsing]

Can't install anything on machine "B" easily. Have to get vendor approval. What I need to do is ssh to "B" and then ssh to a different port on the "B" to start a CLI session.

[salva]

Neither of the two methods exposed on my previous post require installing anything on host B. Everything is done in host A.