[avahi] Avahi daemon "Withdrawing address record"

[Brandon Stafford]

On Tue, Jul 5, 2011 at 5:44 PM, Lennart Poettering
<lennart at poettering.net> wrote:
>> 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.
>
Thanks for this. I'll start reading the avahi-autoipd source.

>
> 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.
>

[root at rascal14$:~]: ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 02:71:82:06:00:14 brd ff:ff:ff:ff:ff:ff
[root at rascal14$:~]: ip link
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 02:71:82:06:00:14 brd ff:ff:ff:ff:ff:ff

This is after executing /etc/init.d/networking restart, which induces
the same series of log messages I pasted earlier. This confirms that
eth0 is missing an inet address, but it doesn't give me (in my state
of ignorance) any additional insight.

By "somebody removed the IPv4LL address again," I assume you mean a
process other than avahi-daemon. Might udhcpc be a candidate? It's
also running. I don't see any other processes running that are
relevant to networking, at least as far as I can tell.

Thanks for the help.

Brandon