Auto network reconfiguring causes DNS lookup to fail

[Joel Roth <joelz@pobox.com>]

Hi,

My laptop's wlan1 interface is connected to a wireless
router, using wpa_supplicant (via wpa_gui).
 
Every few minutes, DNS lookup fails. Output of ifconfig
shows that eth1 and eth1:avahi interfaces have come up.
Output of route shows that eth1 entries have been added to
the routing table.

    Kernel IP routing table
    Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
    10.255.25.0     *               255.255.255.0   U     0      0        0 wlan1
    link-local      *               255.255.0.0     U     0      0        0 eth1
    default         10.255.25.1     0.0.0.0         UG    0      0        0 wlan1
    default         *               0.0.0.0         U     1002   0        0 eth1

I can get connectivity by issuing

    ifconfig eth1 down
    dhclient wlan1

I tried adding the following to /etc/avahi/avahi-daemon.conf
and restarting avahi-daemon, but no change. 

    allow-interfaces=wlan1
    deny-interfaces=eth1

I've used Debian for years without suffering
autoreconfiguration issues.

I see that I have package "iproute" installed, and that it
replaces arpd. Could that be to blame?  Except for wpa_gui,
I'm not using any GUI network management tools. 

Thanks

Joel

-- 
Joel Roth