[Lxc-users] native (non-NAT) routing?

[Ulli Horlacher]

My first Ubuntu 10.04 container is up and running on a Ubuntu 10.04 host,
but the container can only connect to the host (and vice versa), but not
to the world outside.

I saw a lot of configurations for NAT, but I want native routing for my
containers. 



My setup is:

host      zoo 129.69.1.39
container LXC 129.69.1.219
router        129.69.1.254

In LXC.conf is:

lxc.utsname = LXC
lxc.network.type = veth
lxc.network.link = br0
lxc.network.flags = up
lxc.network.name = eth0
lxc.network.mtu = 1500
lxc.network.ipv4 = 129.69.1.219/24


root at LXC:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
129.69.1.0      0.0.0.0         255.255.255.0   U     0      0        0 eth0
0.0.0.0         129.69.1.254    0.0.0.0         UG    0      0        0 eth0

root at LXC:~# ping -c 1 129.69.1.39
PING 129.69.1.39 (129.69.1.39) 56(84) bytes of data.
64 bytes from 129.69.1.39: icmp_seq=1 ttl=64 time=11.5 ms

--- 129.69.1.39 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 11.547/11.547/11.547/0.000 ms

root at LXC:~# ping -c 1 129.69.1.254
PING 129.69.1.254 (129.69.1.254) 56(84) bytes of data.
>From 129.69.1.219 icmp_seq=1 Destination Host Unreachable

--- 129.69.1.254 ping statistics ---
1 packets transmitted, 0 received, +1 errors, 100% packet loss, time 0ms



root at zoo:~# route -n
Kernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
129.69.1.0      0.0.0.0         255.255.255.0   U     0      0        0 br0
0.0.0.0         129.69.1.254    0.0.0.0         UG    100    0        0 br0

root at zoo:~# ping -c 1 129.69.1.219
PING 129.69.1.219 (129.69.1.219) 56(84) bytes of data.
64 bytes from 129.69.1.219: icmp_seq=1 ttl=64 time=0.058 ms

--- 129.69.1.219 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.058/0.058/0.058/0.000 ms

root at zoo:~# ping -c 1 129.69.1.254
PING 129.69.1.254 (129.69.1.254) 56(84) bytes of data.
64 bytes from 129.69.1.254: icmp_seq=1 ttl=255 time=0.509 ms

--- 129.69.1.254 ping statistics ---
1 packets transmitted, 1 received, 0% packet loss, time 0ms
rtt min/avg/max/mdev = 0.509/0.509/0.509/0.000 ms

root at zoo:~# iptables -n -L
Chain INPUT (policy ACCEPT)
target     prot opt source               destination

Chain FORWARD (policy ACCEPT)
target     prot opt source               destination

Chain OUTPUT (policy ACCEPT)
target     prot opt source               destination

root at zoo:~# sysctl -a | grep forward
net.ipv4.conf.all.forwarding = 1
net.ipv4.conf.all.mc_forwarding = 0
net.ipv4.conf.default.forwarding = 1
net.ipv4.conf.default.mc_forwarding = 0
net.ipv4.conf.lo.forwarding = 1
net.ipv4.conf.lo.mc_forwarding = 0
net.ipv4.conf.eth0.forwarding = 1
net.ipv4.conf.eth0.mc_forwarding = 0
net.ipv4.conf.br0.forwarding = 1
net.ipv4.conf.br0.mc_forwarding = 0
net.ipv4.conf.virbr0.forwarding = 1
net.ipv4.conf.virbr0.mc_forwarding = 0
net.ipv4.conf.vethMx2A0v.forwarding = 1
net.ipv4.conf.vethMx2A0v.mc_forwarding = 0
net.ipv4.ip_forward = 1

Any debugging hints?

-- 
Ullrich Horlacher              Server- und Arbeitsplatzsysteme
Rechenzentrum                  E-Mail: horlacher at rus.uni-stuttgart.de
Universitaet Stuttgart         Tel:    ++49-711-685-65868
Allmandring 30                 Fax:    ++49-711-682357
70550 Stuttgart (Germany)      WWW:    http://www.rus.uni-stuttgart.de/