If your EL box has /var/lock mounted tmpfs, and the /var/lock/vtund is being killed at each reboot, you'll see log messages like:
Oct 20 13:29:03 ghostyghost vtund[s]: authentication[5986]: Can't create temp lock file /var/lock/vtund/me2you
Further investigation shows the directory's not there, even if your package did install it:
[root@ghostyghost ~]# ls -l /var/lock/vtund/
[root@ghostyghost ~]# rpm -V !$
rpm -V vtun
S.5....T. c /etc/vtund.conf
missing /var/lock/vtund
And that's when you notice it's mounted in a volatile format:
[root@ghostyghost ~]# df /var/lock
Filesystem 1K-blocks Used Available Use% Mounted on
tmpfs 3941272 8592 3932680 1% /run
The fix is simple:
(Fix it for reboots)
# cat <<eof> /etc/tmpfiles.d/vtund.conf
d /run/lock/vtund 0755 root root -
EOF</eof>
(Fix it for now, too)
# systemd-tmpfiles --create
And get your distro to package it better.
This bug: