avahi-resolve works but mdns

Question

I have an updated debian 11 (bullseye) setup and want to use avahi to connect to locally connected computers.

avahi works, for example:

avahi-resolve -n4 prag11mono.local 

gives prag11mono.local 10.0.0.105 which is correct. however, ping (or ssh) for the same host

ping prag11mono.local
PING prag11mono.local.rpz.GS.local (127.0.0.2) 56(84) bytes of data.
64 bytes from 127.0.0.2 (127.0.0.2): icmp_seq=1 ttl=64 time=0.035 ms

here I do not understand where the rpz.GS.local addition comes from. It is not added to ssh prag11mono.local, but the request goes to 127.0.0.2 as well.

In /etc/nsswitch.conf I have

hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

but getent hosts bhutan.local

returns nothing. I have no /etc/mdns.allow file.

What makes the connection between avahi-daeomon and mdns4? I can restart the avahi-daemon with systemctl; how to resart mdns?

I fear that I miss some installation. I tried to install the package nss-mdns but get unable to locate package despite I find it should be available for bullseye. I installed libnss-mdns and checked that the required files are in `/lib/libnss_mdns*

What is missing? How to debug?

Answer 1

with much confusion of what applies to the current debian 11 (bullseye) solution. I found that I had not installed bind9 (but just the related specific packages) and needed to

systemctl enable named-resolvconf

I guess the defaults for nsswitch.conf was ok. with named-resolvconf running. dig did not return any hint to rpz as before. However, I need not run

systemctl status systemd-networkd
systemctl status systemd-resolved

which return both disabled; inactive. I saw some hints these might be necessary, but likely with another configuration.

It is perhaps important to differentiate between resolvconf and systemd-resolved which do somewhat similar things, but are not compatible. My solution seems to be relying on resolvconf and bind9.