This avoids having to worry about other applications using the tunnel port numbers.
Only works with more recent ssh clients than the version on the 2017 BBBK sg release,
so has to wait until the new release for that platform.
Use
create tunnel on SG: ssh -f -N -R/tmp/SG-XXXXYYYYZZZZ:localhost:22 ...
tunnel in from server: ssh -o ProxyCommand="nc -U /tmp/SG-XXXXYYYYZZZZ" ... bone@localhost (because ssh's -p option doesn't allow for a unix domain socket)
rsync on data server: rsync -e "-e 'sshpass -p bone ssh -o ProxyCommand=\"nc -U /tmp/SG-XXXXYYYYZZZZ...\" ...' ..."
This avoids having to worry about other applications using the tunnel port numbers. Only works with more recent ssh clients than the version on the 2017 BBBK sg release, so has to wait until the new release for that platform.
Use
ssh -f -N -R/tmp/SG-XXXXYYYYZZZZ:localhost:22 ...ssh -o ProxyCommand="nc -U /tmp/SG-XXXXYYYYZZZZ" ... bone@localhost(because ssh's-poption doesn't allow for a unix domain socket)rsync -e "-e 'sshpass -p bone ssh -o ProxyCommand=\"nc -U /tmp/SG-XXXXYYYYZZZZ...\" ...' ..."