[Users] How to configure range of auto-generated MAC addresses for VETH devices?

[Roman Haefeli]

Hi!

When adding VETH interfaces to containers with the following command:

vzct set CTID --netif_add eth0,,,,vzbr0 --save

an automatically generated MAC address of the format  00:18:51:XX:XX:XX
is configured for the container. 

This can cause problems with bridges, since bridges seem to use the MAC
address of the member with the lowest MAC address. So if I start said
container on the hostnode, and the hostnode's physical NIC has a MAC
00:30:48:XX:XX:XX, the MAC of vzbr0 switches from  00:30:48:XX:XX:XX to
00:18:51:XX:XX:XX (and vice versa when stopping said CT).

This MAC address switching causes network lags for all members of the
bridge vzbr0. 

Of course, I can manually change the configured MAC address in each CT's
ctid.conf (which I did in the past), but I wonder if there is a way to
configure the range of the auto-generated MAC addresses.

Roman