I am running Xubuntu 17.10 with vpnc installed (version 0.5.3r550-3)
Everytime dhclient runs my vpnc connection fails:
From /var/log/syslog
[...] dhclient[26917]: DHCPDISCOVER on eth0 to [...]
[...] dhclient[26917]: DHCPREQUEST of [...]
[...] dhclient[26917]: DHCPOFFER of [...]
[...] dhclient[26917]: DHCPACK of [...]
...
[...] vpnc[26788]: esp sendto: Message too long
After that i have to manually run, else it does not work anymore
sudo vpnc-disconnect
sudo vpnc
Can i automate that?
Edit:
what I have found out so far is that dhclient calls /sbin/dhclient-script and this updates /etc/resolv.conf based on received values -- which are different what vpnc sets.
Maybe a solution would be to set static values here and prevent dhclient to overwrite the settings in /etc/resolv.conf.
/usr/sbin/vpnc-disconnect && /usr/sbin/vpnc
-- i will so some tests