The problems seems to be apparmor, which is restricting permissions. Problem can be solved by changing the file /etc/apparmor.d/usr.sbin.fwknopd and add the following lines:
/run/xtables.lock rwk, network inet dgram, network inet6 dgram, -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1598506 Title: apparmor profile prevents fwknop-server from starting To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/fwknop/+bug/1598506/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
