All,
Having fetched the draft 6.1 version of IEEE 802.1ag and trying to understand it, I ran into some conceptual questions I cannot answer myself. Maybe there's someone out here able to help?
(1) 802.1ag is set out for end-to-end management and I would assume IEEE to make things as backwards compatible as possible, that is, allow
802.1ag-enabled clouds to be connected via 802.1ag-agnostic older equipment. I would have believed 802.1ag frames just traverse such agnostic equipment transparently. (Maybe this is wrong. Then, my problem had vanished, of course.) Now seeing they use dstMAC==01-80-C2-00-00-0x I have doubts about my guess as I happen to remember such MACs MUST NOT be forwarded at all, per 802.1D. So what about backwards compatibility and 802.1ag-agnostic equipment then?(2) Again addressing. It appears to me that the ME level shall be signified in the last three bits of the MAC address, with ME level from
0..7. That'd make 01-80-C2-00-00-00 to -00-07, which I believe to conflict with STP, PAUSE/.3x and LACP. What's wrong or missing here (don't believe IEEE to make conflicting specs ;-)?(3) Let's put 802.1ag and STP together, will that go? If we have a topology with loops (presuming this is supported), will 802.1ag care about it and resolve or will it let STP do the job? My guess is that having both active simultaneously, STP may rearrange topology underneath 802.1ag, which in turn tries to find an alternative path via AIS and LTMs at the same time that STP processes a TC, and that looks strange to me now. Any ideas?
(4) 802.1ag says that it makes use of an extended discovery mechanism that can be found in chapter 12 of 802.1Q -- fine. But given .1Q invented some discovery mechanism prior to .1ag, what did they intend it for, wo used it and what for? I must admit never having seen such .1Q discovery so far.
Any ideas will be greatly appreciated. Thanks, /Thomas.