Re: [homenet] Info about IS-IS demo from Bits N Bites Prague

[Mikael Abrahamsson <[e-mail]>]

On Fri, 18 Sep 2015, Juliusz Chroboczek wrote:

>> - Transport: both L2 & IPv6 (Link-Local)
>
> Which is suggested for Homenet?  The two don't interoperate, right?

Well, there is nothing that stops a device to form P2P neighbors over both 
ways, but since the feedback historically has been that L2 is hard in some 
devices (the protocol stack implementation is pretty much geared towards 
IPv4/IPv6), I'd suggest IPv6 LL for homenet.

>> - Point-to-Multi-Point or Broadcast over L2 or IPv6
>
> Which is suggested for Homenet?  Or do the two interoperate?

Historically you configure an interface as either LAN (default for 
ethernet) or P2P (default for point to point interfaces). My suggestion 
would be to use P2MP everywhere for simplicity, but I would really prefer 
to use LAN for wired ports, but since LAN ports can be bridged over all 
kinds of physical media, I guess P2MP is the safest way to go for 
everything to make sure we're not using multicast apart for discovery.

>> These are standard IS-IS wide metrics, although it makes use of the per
>> neighbor metrics available with draft-lamparter-isis-p2mp.
>
> Does this interoperate with standard IS-IS?

No, the draft explicitly states that P2MP is a new hello type and that 
P2MP routers must discard LAN and P2P Hello PDUs.

>> To address this, links without metric information (i.e. direct links
>> between clients) will not be considered for SPF. Since 802.11 frames
>> from clients to clients are relayed by the AP, this actually can reflect
>> the metrics better.
>
> Are you assuming that there are no dumb layer 2 APs in the network?

Yes, that is a tradeoff. If there are L2 APs then insight into the wifi 
layer is lost.

-- 
Mikael Abrahamsson    email: [e-mail]