Subject: source IP messed up on multihomed guest with 2.6.38.6-vs2.3.0.37-rc15
From: Thomas Weber <l_vserver@mail2news.4t2.com>
Date: Fri, 20 May 2011 02:03:40 +0200


My config:
debian 6.0.1 64bit

util-vserver: 0.30.216-pre2938

Host with 2 interfaces:
eth0
        address         192.168.105.1
        netmask         255.255.255.0
        broadcast       192.168.105.255
        network         192.168.105.0
        gateway         192.168.105.254

eth1
        address         192.168.1.54
        netmask         255.255.255.0
        network         192.168.1.0
        broadcast       192.168.1.255
        gateway         192.168.1.254

a guest with interfaces in both Networks (bcast,dev,ip,prefix)

# cat interfaces/00/*
192.168.105.255
eth0
192.168.105.21
24

# cat interfaces/99/*
192.168.1.255
eth1
192.168.1.64
24


Kernels are plain kernel.org + vserver patch

with 2.6.37.3-vs2.3.0.37-rc3.2
I can connect hosts on 192.168.1.0/24 just fine (from inside the guest)

with 2.6.38.6-vs2.3.0.37-rc15
this doesn't work anymore.

for ping tcpdump on the host shows me:
01:50:26.971098 IP 192.168.105.21 > 192.168.1.8: ICMP echo request, id 3185, seq 1,
length 64
01:50:27.976957 IP 192.168.105.21 > 192.168.1.8: ICMP echo request, id 3185, seq 2,
length 64

so it obiously takes the wrong source address (same with tcp or udp).

explicitly specifying 192.168.1.64 as source for ping/nc works.


do i miss something or is this a bug?

  Tom