[ntp:questions] zeroconf for ntpd?

Wolfgang S. Rupprecht wolfgang.rupprecht+gnus200705 at gmail.com
Tue May 22 16:46:37 UTC 2007


I just watched a Google Talk series video about Bonjour, their
zero-configuration hack.  Basically they use link-level multicasts to
figure out who is out on the local net and who can do what.  They even
go so far as assigning IP addresses and hostnames via this cloud of
participating hosts.  Getting away from having users edit config files
(after reading a half dozen man pages) seems like a good thing.

It looks like quite a bit of work went into making ntpd do some of the
same things. Now that multicast no longer binds to only the first
interface it finds, it looks like it may almost be possible to deliver
an ntp config file that "just works" yet doesn't beat up the pool
servers too much.

Can folks help me flesh this out?  Will this work?

/etc/ntp.conf:

    restrict default nomodify notrap nopeer
    restrict 127.0.0.1 
    restrict -6 ::1
    broadcast ff02::101             # ipv6 link-local multicast
    broadcast ff05::101             # ipv6 site-local multicast
    broadcast 224.0.1.1     ttl 1   # ipv4 multicast
    orphan 5
    multicastclient ff02::101       # ipv6 link-local multicast
    driftfile /var/lib/ntp/drift

plus on the first 2 hosts only:

    server 0.fedora.pool.ntp.org dynamic
    server 1.fedora.pool.ntp.org dynamic
    server 2.fedora.pool.ntp.org dynamic

Any bright ideas of figuring out quickly if the cloud needs to grow a
few external connections?  The big hammer seems to be to parse the
'ntpq -pn' output with a shell script and then add the pools servers
at runtime if nobody in the cloud has any external pool links yet.

Ideas? Comments?

-wolfgang
-- 
Wolfgang S. Rupprecht                http://www.wsrcc.com/wolfgang/
Hints for IPv6 on FC6 http://www.wsrcc.com/wolfgang/fedora/ipv6-tunnel.html




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