[Lxc-users] Multiple lxc containers with sameIP/ethernet address

[Jäkel, Guido]

>>> I have a set up where there are multiple short lived containers (sharing the
>>> same IP address) in a host.
>
>>Why? Don't do that.
>
>I agree...what is your goal?

As others said, this is very "free-spirited" and typically only used in a high availability cluster setup or other failover scenarios.

You might use the "arping" package to explicitly broadcast the changing of the MAC for the IP by sending out additional "unsolicited ARP announcements" right after taking up the interface in the container

	/sbin/arping -c 1 -b -U  $IP

While taking up an interface with an IP address, such a package is already sent out. But it might be swallow by a switch because it's configured or even just by a bad firmware.

Because I'm working with this HA things I know that some switches will remember just *one* IP per MAC and will be confused by any alias IP assignments.