Static MAC addresses - How does FreeNAS comes up with 02:xx:xx:xx:xx:0b ?

[Ravefiend]

I'm thinking of putting in fixed MAC addresses for my jails but I'm a little curious to know how FreeNAS makes up these virtual MAC addresses. In my observation, it appears to be something like 02:xx:xx:xx:xx:0b given the list of MAC addresses I'm currently seeing among the jails I have running.

02:25:70:00:13:0b
02:c3:1c:00:0e:0b
02:e9:64:00:0f:0b
02:db:3d:00:11:0b
02:51:bd:00:0f:0b
02:73:98:00:12:0b
02:c4:f6:00:13:0b
02:5b:11:00:14:0b
02:fc:6d:00:15:0b
02:84:ee:00:10:0b
02:c9:22:00:0d:0b
02:b1:42:00:17:0b

The 02 at the beginning is clear to me (private range), as per references like What range of MAC addresses can I safely use for my virtual machines?, but what about the ending 0b? Does that serve any specific purpose on FreeNAS of BSD in general?

 

[dlavigne]

Were you able to find the answer to this?

 

[Ravefiend]

No I haven't been able to track this down yet, despite my efforts trying to find some references in the FreeNAS source as well.

 

[dlavigne]

Yeah, I don't think it's written down anywhere and is instead somewhere in the src code or either ifconfig or jail.