[Dnsmasq-discuss] v2.82, Linux: but after restart no reverse lookup, behind-veth VMs not served

[Steffen Nurpmeso]

Hello!

This is my first post here, so please let me first say "thanks!",
i am using this software for i think 18 years? as a per-PC DNS
cache, and also as one of the remote stations when writing
a caching stub DNS resolver myself.

I am wondering about two issues i see on this laptop that i use,
and one of those is definetely new, it changed "some months ago",
the other i do not know, i see it ever since i rewrote my VM
"driver" to not use proxy_arp but instead a network namespace that
is connected to the host via veth pair.

I use a default 2.82 with default "example" configuration (the
CRUX-Linux i use since last year just patches some paths in it),
extended by appending

  addn-hosts=/x/vm/hosts.txt
  #interface=lo
  listen-address=127.0.0.1
  interface=v_n

This is a "${ip} link add v_n type veth peer name v_i", and it
does exist already when dnsmasq is started.

  #listen-address=10.0.0.1
  #log-dhcp
  #dhcp-range=10.1.1.1,10.254.254.254,255.0.0.0,24h
  #no-dhcp-interface=lo
  #no-dhcp-interface=br0
  bogus-priv
  no-poll
  selfmx
  resolv-file=/etc/resolv.conf
  cache-size=2142
  #log-queries=extra
  #conf-dir=/etc/dnsmasq.d/,*.conf

With this, at least if i suspend and resume the laptop, i can no
longer perform reverse lookups, as dnsmasq will refuse to do it,
with NXDOMAIN.  If i do "dig @OTHER-DNS-FROM-resolv.conf -x" i get
through.

Ditto, if i start VMs in the netns linked in via interface=v_n
(created in the network namespace and their .ifup.sh is
   ip link set dev $1 master v_br
   ip link set $1 up
where v_br is just a bridge operating on the other end of v_n,
inside in the netns), these VMs cannot reach the outer world, name
lookup will fail.  They can reach the host and the host can reach
them.

Both of these issues vanish if i restart dnsmasq, but whereas this
can be worked around easily upon resume i wonder why it happens,
and finally thought it would be best to subscribe for a bit, and
report it.

Ciao from Germany,

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)