#805401 ping6 does not resolve Avahi .local addresses by default

Package:
libnss-mdns
Source:
nss-mdns
Description:
NSS module for Multicast DNS name resolution
Submitter:
David Godfrey
Date:
2019-12-11 10:21:07 UTC
Severity:
wishlist
#805401#5
Date:
2015-11-17 19:52:37 UTC
From:
To:
Dear Maintainer,

   * What led up to the situation?
   * What exactly did you do (or not do) that was effective (or
     ineffective)?
   * What was the outcome of this action?
   * What outcome did you expect instead?

*** End of the template - remove these template lines ***
Lets say we have a host called foo on the local network that is correctly
configured to work with avahi and ipv6
        ip addr show eth0
        2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast
state UP group default qlen 1000
            link/ether ****************
            inet 192.168.1.5/24 brd 192.168.1.255 scope global eth0
               valid_lft forever preferred_lft forever
            inet6 fe80::216:3eff:fe80:c25b/64 scope link
               valid_lft forever preferred_lft forever

running
        ping foo.local
works just fine and shows the IP address pinged as 192.168.1.5

running
        ping6 -I eth0 fe80::216:3eff:fe80:c25b
works just fine and shows the IP address pinged as fe80::216:3eff:fe80:c25b

running
        avahi-resolve-host-name foo.local
returns
        foo.local       fe80::216:3eff:fe80:c25b

However
        ping6 -I eth0 foo.local
Fails with error
        unknown host
It should have pinged fe80::216:3eff:fe80:c25b

It appears that for an avahi .local address ping6 only resolves the ipv4
address, the same as ping does.
#805401#10
Date:
2018-10-06 14:53:00 UTC
From:
To:
Dear Maintainer,

just a moment after writing I found an article, saying to modify
nsswitch.conf as follows

hosts:          files mdns_minimal [NOTFOUND=return] dns mdns
#hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4

Maybe this could be a setting for everyone?

https://debian-administration.org/article/655/Running_IPv6_in_practice


thanks

Ben
#805401#15
Date:
2018-10-06 14:44:10 UTC
From:
To:
Dear Maintainer,

cool that I found someone already described the problem.

It still exists in 2018.
#805401#20
Date:
2019-07-05 17:30:42 UTC
From:
To:
Control: reassign -1 libnss-mdns

This isn't an issue specific to ping/ping6. If the reference to mdns in
nsswitch.conf needs to be modified in some way, or the documentation
needs to be changed, this should be handled within the mdns related
packages.

noah
#805401#29
Date:
2019-12-11 10:19:34 UTC
From:
To:
Control: retitle -1 ping6 does not resolve Avahi .local addresses by default
Control: severity -1 wishlist
Control: forwarded -1 https://github.com/lathiat/nss-mdns/issues/62
Control: merge 466014 -1
Control: affects 466014 iputils-ping

The reason why this is not the default is that it significantly slows
down name resolution in some programs. More details are available in
upstream bug <https://github.com/lathiat/nss-mdns/issues/62>.

The next upload of nss-mdns will mention this in README.Debian. I don't
intend to change the default in Debian unless the upstream developer of
nss-mdns changes their recommendation, but you are welcome to make this
configuration change locally.

    smcv