On executing a custom command (ex: a "uname -u") on a disconnected node located on an external LAN separated by a firewall, the command freezes and Webmin waits undefinitely and any Timeout never come.
By analyzing the traffic with Wireshark, I have observed only some TCP-SYN packets are sent to the remote Webmin but never any ACK.
The "custom command" module seems to be the unique module which freezes. Other "cluster" Webmin modules detect a Timeout.
Any idea ?