Debian 10 UDP LCM tunnel

[Christian Lees]

We are having a few issues getting an LCM tunnel to work using UDP on a Debian 10 system.  All our previous implementations were with earlier versions of Debian, 8. and 9.

With the tunnel started on a Debian 8 system

debian8> bot-lcm-tunnel

Then if we try to connect with a Debian 10 system

debian10> bot-lcm-tunnel -u debian8

We get the following errors on the server system, debian8

errno 111, send_status -1 :error sending UDP Data: : Connection refused

Connection may be back up after 0.006700sec send_status=116 numSuccessful=4

perror: : Success

errno 111, send_status -1 :error sending UDP Data: : Connection refused

Connection may be back up after 0.007352sec send_status=116 numSuccessful=4

perror: : Success

errno 111, send_status -1 :error sending UDP Data: : Connection refused

Connection may be back up after 0.001800sec send_status=116 numSuccessful=4

perror: : Success

If we try to establish the tunnel using TCP it all just works as expected.  We can't seem to work out what has changed in 10.  I have played around with the rp_filter flags with no success.  The systems aren't running any firewalls.

Any help will be appreciated.

Christan