This bug was fixed in the package knockd - 0.7-1ubuntu1.18.04.3
--------------- knockd (0.7-1ubuntu1.18.04.3) bionic; urgency=medium
* d/knockd.service: - use Wants=network-online.target (LP: #1912826)
-- Dan Streetman <email address hidden> Mon, 25 Jan 2021 16:16:15 -0500
This bug was fixed in the package knockd - 0.7-1ubuntu1. 18.04.3
--------------- 18.04.3) bionic; urgency=medium
knockd (0.7-1ubuntu1.
* d/knockd.service: online. target (LP: #1912826)
- use Wants=network-
-- Dan Streetman <email address hidden> Mon, 25 Jan 2021 16:16:15 -0500