My understanding is the AVB is hardware dependent, and will require newer ethernet hardware. Not just the interfaces on the computer, but hubs and switches as well.
(what makes the protocol so promising is this silicon-level integration.)
On 2012 mac book pro 15" (non-retina) here's what I get:
$ avbdeviced --enable-interface en0
avbdeviced version 109.1.1
attempting to enable AV mode returned YES
Then the system posts a dialogue box "avbdeviced is trying to modify the system network configuration. Type your password to allow this." (cancel) (Modify Configuration)
upon entering password / clicking Modify Configuration I get:
attempting to enable AV mode returned YES
commit changes returned YES
apply changes returned YES
Enabled AVB on interface "en0"
and then:
$ avbdeviced --list-interfaces
avbdeviced version 109.1.1
ifname enabled
------ -------
en0 yes
And then:
$ avbdeviced --disable-interface en0
avbdeviced version 109.1.1
attempting to disable AV mode returned YES
commit changes returned YES
apply changes returned YES
Disabled AVB on interface "en0"
I've heard tales of AVB devices then showing up (if connected) in Audio Midi setup. Nothing connected, nothing showing up there on my system.
-jeremiah