Red Hat Bugzilla – Bug 142411
nss-mdns provides link-local mDNS hostname lookups
Last modified: 2014-03-16 22:51:06 EDT
Fedora already ships with mDNSResponder (part of howl) which can
respond to mDNS queries. That corresponds to the server portion of a
normal DNS setup. nss-mdns is an NSS plugin that adds the
corresponding client code to glibc.
With this package installed and configured properly (all I had to do
was add 'mdns4' to the hosts: line in nsswitch.conf) machines can
refer to each other by name even in the absense of a DNS server,
either with valid DHCP-assigned IP addresses or self-assigned
(Zeroconf/IPv4LL) addresses. I've tried it with two linux boxes and a
Mac, both on a private and public network.
This feature is a part of Apple's Rendezvous technology (giving better
Mac interoperability) and would also make running home/small office
networks a lot easier (no DNS server needed! Plug in a new machine or
a laptop and instantly refer to it by its name!)
Created attachment 108226 [details]
a specfile for nss-mdns
I guessed on the Group. It doesn't modify nsswitch.conf, but I don't know how
that should be done.
authconfig is normally what modifies nsswitch.conf.
Want to maintain nss-mdns? >:)
Uli, is there planned to be any mDNS work in glibc directly that would conflict
with this, or is a new nss module the way to go?
The approach taken by the current nss-mdns is wrong. The problem is that the
broadcasted results are not used. The result is that the network is flooded
with unnecessary requests.
I talked to the author some time back and he acknoledged this. He said he is
currently writing a program similar to the nDNSresponder which then will also
listen for the broadcast traffic and be able to answer requests from the
Without this functionality the nss-mdns module is dangerous if you have more
than a couple of machines.
I'm not sure whether I trust the author to make all the changes in a timely
manner. If not, I'll add appropriate code myself. Until it is resolved one way
or another, we should not provide any half-cooked mdns support.
OK. Deferring, then.