Linux

Recently i found this for give to docker a "personal" ip

Code:

    ip addr del 10.1.1.133/24 dev eth0
    ip link add link eth0 dev eth0m type macvlan mode bridge
    ip link set eth0m up
    ip addr add 10.1.1.133/24 dev eth0m
    route add default gw 10.1.1.1

On container i did

Code:

    CID=$(docker run -d ...)
    pipework eth0 $CID 10.1.1.133/24@10.1.1.1

This works fine if host and docker containers all are on same subnet(10.1.1.0/24 in this case)
But if i want to use a different subnet for dockers?
For example 10.2.2.0/24?

I have tried a iptables masquerade,but nothing works,the docker container cannot ping or reach external network(internet).

Code:

    iptables -t nat -A POSTROUTING -m iprange --src-range 10.2.2.2-10.2.2.255 -o eth0 -j MASQUERADE

Of course ip forwarding is enabled

---------- Post updated 29-06-15 at 05:40 PM ---------- Previous update was 28-06-15 at 10:02 PM ----------

Solution found.
The host must setup as router,enable iptables NAT and enable route to new ip class,in this case eth0m is the bridged network

Code:

    iptables -A FORWARD -i eth0m -o eth0m -j ACCEPT
    iptables -A FORWARD -i eth0m -o eth0m  -m state --state NEW,RELATED,ESTABLISHED -j ACCEPT
    iptables -t nat  -A POSTROUTING -o eth0m -j MASQUERADE

pipework must use the new router,in this case is 192.168.0.254

Code:

    pipework eth0 $DOCKID 10.8.3.1/24@192.168.0.254

and finally route must be added,in this case 10.8.3.0 is the other ip class

Code:

    route add -net 10.8.3.0 netmask 255.255.255.0  dev eth0m