[avahi] Avahi daemon "Withdrawing address record"

[Lennart Poettering]

On Tue, 05.07.11 17:41, Brandon Stafford (brandon at rascalmicro.com) wrote:

> Hi,
> 
> I'm working on debugging an embedded Linux board that uses avahi
> 0.6.25 for mDNS. When DHCP succeeds, local name resolution works as
> expected. When DHCP fails, as it does when my board is connected
> directly to my laptop, it appears that avahi successfully claims a
> link-local address, but then immediately throws it away.

Note that avahi-autoipd implements IPv4LL and avahi-daemon does not know
much about it, it just watches netlink.

> Here's what I see in /var/log/messages:
> 
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: Joining mDNS
> multicast group on interface eth0.IPv4 with address 169.254.124.120.
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: New relevant
> interface eth0.IPv4 for mDNS.
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: Registering
> new address record for 169.254.124.120 on eth0.IPv4.
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: Withdrawing
> address record for 169.254.124.120 on eth0.
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: Leaving mDNS
> multicast group on interface eth0.IPv4 with address 169.254.124.120.
> Jul  1 04:57:06 rascal14 daemon.info avahi-daemon[602]: Interface
> eth0.IPv4 no longer relevant for mDNS.
> 
> These log messages are getting created by avahi-core/iface.c, but I'm
> not sure why avahi daemon would claim and then release an address.
> >From what I can tell, the actual link-local address negotiation is
> handled by /usr/sbin/zeroconf, which is actually zeroconf 0.9 from
> http://www.progsoc.org/~wildfire/zeroconf/, but it's not clear to me
> how or if that's communicating with avahi-daemon.

Something happened so that Avahi didn't consider the interface relevant
anymore. This could be because somebody removed the IPv4LL address
again. To find out it would be useful if you pasted the output of "ip
addr" and "ip link" after this happened.

Lennart

-- 
Lennart Poettering - Red Hat, Inc.