On Sun, Apr 3, 2022 at 4:25 AM Alexander Puchmayr <alexander.puchm...@linznet.at> wrote: > > wasn't systemd per se, it was an update of /etc/nsswitch.conf. The old version > had > > Hosts: mymachines files myhostname dns > > while the new version contains > > Hosts: mymachines resolve [!UNAVAIL=return] files myhostname dns > > The extra "resolve [!UNAVAIL=return]" makes the difference. It loads the > glibc's plugin nss-resolve [1], which then calls systemd-resolved [2], which > interprets '.local' as mDNS address. The mDNS is not activated on purpose, it > seems to be some default setting of the router which does not appear in the > configuration pages (or I didn't find it).
So, the nsswitch file does direct glibc to use the systemd resolve library, but it is resolved that is using mDNS. Did you check your resolved.conf? Does it have MulticastDNS=no set? If it isn't explicitly set you'd probably need to check the build-time options for what the defaults are these days. I don't see how your router would impact this. You don't even need DHCP/DNS at all to use mDNS, as long as the hosts implement mDNS and link-local autoconfig. (Those are addresses in the range 169.254.0.0/16 and fe80::/10. Many OSes support this at this point by default.) In any case, disabling resolved would certainly solve the issue, but if you want to still use it you can fine-tune the mDNS settings on it. -- Rich