[lxc-users] venet like networking in LXC possible ?

[Fajar A. Nugraha]

On Wed, May 21, 2014 at 10:34 PM, Marc MAURICE
<marc.maurice at objectif-libre.com> wrote:
> Thanks a lot.
> I tried the config and it's *almost* working.
>
> When pinging the output from the container : packets are going out with the
> good MAC.
>
> However, nothing in return.
> From tcpdumps I figured out that my parent host is not responding to arp for
> the container IP.
>

well ... nothing outside the server should even know about the
container's MAC address. Because if the network setup is the same as
mine, then the provider's router would route all traffic for the
container thru main server's IP. In other words, the provider's router
will ask for the server's IP, not the container's IP.

Can you give real IP addresses? The easiest way to check, is that if
your server's main IP and additional IP are on DIFFERENT subnets (e.g.
111.94.248.114/24 and 65.55.58.201/32), then it's routed setup. If
it's on the SAME subnet, then you can't copy my setup, because the
network config is different.

> How do I tell my host to respond to those arp queries ?



Assuming that your setup is DIFFERENT from mine (that is, your server
AND container IP are on the same subnet), you could probably try
something like this. Note that you should make SURE you have console
access (e.g. KVM, ILO) to your server incase something goes wrong
before trying this.

Asssuming:
- the provider's router IP is 192.168.124.1/24
- your server is connected to provider's router thru eth0, with ip
address 192.168.124.179/24, MAC 00:16:3e:46:76:9e
- your server is connected to the container thru br0 bridge
- the container's IP is 192.168.124.180

On the server:
- remove IP address on the bridge: ifconfig br0 0.0.0.0 up
- add container's IP information in arp table: arp -i eth0 -s
192.168.124.180 00:16:3e:46:76:9e pub
- add route to the container via the bridge: ip route add
192.168.124.180 dev br0

On the container: pretty much the same as the previous setup. Except
now use the server's eth0 ip address as the gateway
- ifconfig eth0 192.168.124.180/32 up
- ip route add 192.168.124.179 dev eth0
- ip route add default via 192.168.124.179


If that works, then you can setup the appropriate config file (e.g
/etc/network/interfaces) so the process would start automatically.

-- 
Fajar