My VPN client sometimes can't bind to the UDP port (500) it uses. It seems to leave behind a "bind" to port 500 on a previous run, even though it has quit.
The port is reported as "already in use" (Mac os X), but doesn't have an associated process:
$ sudo netstat -na | grep "udp.*\.500\>" udp4 0 0 192.168.50.181.500 *.* udp4 0 0 192.168.29.166.500 *.*
sudo lsof doesn't show a process on port 500 (ie
sudo lsof -i:500 -P reports nothing).
I can successfully use the VPN client after rebooting the machine, but am hoping for a less disruptive way to clear the state.