I can confirm that the vtun package in mantic-proposed has fixed the bug for me.
Test done: 1. Install vtun from mantic-proposed 2. Execute vtund. $ vtund vtund[2312]: Can not open /etc/vtund.conf VTun ver 3.X 02/18/2024 Usage: Server: vtund <-s|-i> [-f file] [-P port] [-L local address] Client: vtund [-f file] [-q] [-p] [-m] [-t timeout] <host profile> <server address> The help message shows "-s" has now been enabled in vtund. Test result: the errors with vtun has been fixed. Package tested: $ dpkg -l | grep vtun ii vtun 3.0.4-2ubuntu0.23.10.1 amd64 virtual tunnel over TCP/IP networks -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1881522 Title: [SRU] vtun not running on ubuntu 20.04 LTS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/vtun/+bug/1881522/+subscriptions -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs