If that does not work I’d suggest trying the following (which mimics essentially what PBS is doing to make the connection in the interactive job):
Submit an interactive job that we know will not run (give it a really high ncpus request so that it will remain queued).
While that job is queued, look at it in qstat -f and note the full value of PBS_O_HOST in the Variable_List attribute.
On the same host that qsub -I is waiting for the job to start, run netstat -anp | grep qsub | grep LISTEN, note the port number (after the “0.0.0.0:”).
Now log into node0115 as root and issue the command “telnet X Y”, where X is the PBS_O_HOST value from qstat -f and Y is the port number from netstat.
Do you get “Escape character is ‘^]’.”, or something else?