An option to disable masquerading

[orivej]

There is a host that has a set of unused globally routable IPv6 addresses to assign to eth1 or its slaves, and the setup that works is to bring eth1 up without any IP address, let ipvlan-docker-plugin create ipvlan slaves for Docker containers and assign them addresses from the available set of addresses.

In the output of ipvlan-docker-plugin --gateway fe80::1 --ipvlan-subnet …::e2a0/124 -d there is a warning:

INFO[0000] IPVlan network driver initialized successfully
DEBU[0041] Handshake completed
DEBU[0041] /sbin/iptables, [--wait -C POSTROUTING -t nat -s …::e2a0/124 -j MASQUERADE]
DEBU[0041] /sbin/iptables, [--wait -I POSTROUTING -t nat -s …::e2a0/124 -j MASQUERADE]
WARN[0041] error setting up outboud nat: iptables failed: iptables --wait -I POSTROUTING -t nat -s …::e2a0/124 -j MASQUERADE: iptables v1.4.21: invalid mask `124' specified
Try `iptables -h' or 'iptables --help' for more information.
 (exit status 2) 

which indicates that containers would not be routable from the outside if ipvlan-docker-plugin succeded in enabling masquerading.