Re: [v6ops] [EXTERNAL] Re: draft-ietf-6man-grand : saving lookups

["Templin (US), Fred L" <[e-mail]>]

Hi Ted – see below for response to your question:


Address resolution is a different question, though; if a node on the NBMA link wants
to resolve the address of a subnet router for a target destination it can send NS(AR)
to the solicited-node multicast address corresponding to the target. The “multicast”
will then go to exactly one node, which is the target subnet router, and the resultant
NA(AR) is unicast back to the (single) node that sent the NS. Very efficient, and
again without disturbing the massive numbers of other nodes on the link.

Do WiFi base stations implement this correctly, or do they broadcast?

In the NBMA case, we leverage unicast routing in an overlay BGP routing topology
based on the NS target address. For a WiFi base station, it could use broadcast
but that might not scale well if the number of nodes in the broadcast domain is
large. Alternatively, it could do the unicast/multicast emulation the same as
for the NBMA case if an overlay BGP routing topology is established.

Thanks - Fred