I ran tcpdump 'host ubuntu20 and port domain' on my router and looked at all the other NXDOMAIN at boot time besides this one.
1. PTR request on the IPv4 address of my virbr0 interface. Gone after uninstalling a couple libvirt-* packages 2. PTR request on ONE of my IPv6 addresses. It's not obvious to me which address gets picked for that PTR query. I disabled IPv6 ULA on my router and the PTR request just moved to a different address. 3. SOA local. ?? I also found that NetworkManager needs to be told "connectivity-check.ubuntu.com has no AAAA record" about 12 times during boot, that seems a bit excessive? (this is not NXDOMAIN) -- You received this bug notification because you are a member of Ubuntu Touch seeded packages, which is subscribed to systemd in Ubuntu. https://bugs.launchpad.net/bugs/1880258 Title: Add trailing dot to make connectivity-check.ubuntu.com. absolute and reduce NXDOMAIN warning noise Status in network-manager package in Ubuntu: Fix Released Status in systemd package in Ubuntu: Triaged Status in network-manager source package in Focal: Confirmed Bug description: I normally don't like this, but it's a one-character change so it's easier to start with the solution: diff -u -r1.1 /usr/lib/NetworkManager/conf.d/20-connectivity-ubuntu.conf --- /usr/lib/NetworkManager/conf.d/20-connectivity-ubuntu.conf +++ /usr/lib/NetworkManager/conf.d/20-connectivity-ubuntu.conf @@ -1,2 +1,2 @@ [connectivity] -uri=http://connectivity-check.ubuntu.com/ +uri=http://connectivity-check.ubuntu.com./ Making this name absolute instead of relative avoids spurious resolutions of "connectivity-check.ubuntu.com.your_domain." This removes a fair amount of NXDOMAIN error noise in journalctl. Observing the issue and the fix requires 3 terminals: 1. tcpdump -i any 'port domain' 2. journalctl --boot -u systemd-resolved -f 3. nmcli c down "Wired connection 1"; nmcli c up "Wired connection 1" => observe the NXDOMAIN noise over a couple few minutes Now make the hostname absolute with the trailing dot above and run: systemctl reload NetworkManager Wait 1 min for things to stabilize. Test again: nmcli c down "Wired connection 1"; nmcli c up "Wired connection 1" => observe non-zero but significantly reduced NXDOMAIN noise over a couple few minutes Originally reported at https://askubuntu.com/a/1242611/117217 Plenty of people annoyed by NXDOMAIN warnings, just Google it. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/network-manager/+bug/1880258/+subscriptions -- Mailing list: https://launchpad.net/~touch-packages Post to : touch-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~touch-packages More help : https://help.launchpad.net/ListHelp
