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 nss-mdns module. 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.