Wrong IPv4 source address selected

This is 2.6.17-rc6 running on a 32-bit ppc (the same ARC=ppc PReP machine that had the x_tables problem, so it has the x_tables alignment first fix too).

The problem: IPv4 source addresses are sometimes selected wrong (packets are sent to the internal 172.30 network with external 193.40 source address). I have seen this with ARP requests for 172.30.0.x addresses and UDP multicast traffic (avahi query from 193.40.37.61:5353 to 224.0.0.251:5353 on eth1).

I have 2 physical network interfaces (+ loopback + unconfiured sit0)

2: eth0: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 08:00:3e:28:c4:a2 brd ff:ff:ff:ff:ff:ff
    inet 193.40.37.61/23 brd 193.40.37.255 scope global eth0
    inet6 2001:bb8:2002:2400:a00:3eff:fe28:c4a2/64 scope global dynamic
       valid_lft 2591964sec preferred_lft 604764sec
    inet6 fe80::a00:3eff:fe28:c4a2/64 scope link
       valid_lft forever preferred_lft forever
3: eth1: <BROADCAST,MULTICAST,UP,10000> mtu 1500 qdisc pfifo_fast qlen 1000
    link/ether 00:00:94:7a:31:8c brd ff:ff:ff:ff:ff:ff
    inet 172.30.0.1/24 brd 172.30.0.255 scope global eth1
    inet6 fe80::200:94ff:fe7a:318c/64 scope link
       valid_lft forever preferred_lft forever

ip route ls:
172.30.0.0/24 dev eth1  proto kernel  scope link  src 172.30.0.1 193.40.36.0/23 dev eth0  proto kernel  scope link  src 193.40.37.61 default via 193.40.36.1 dev eth0

-- 
Meelis Roos (mroos@linux.ee)