[IPv6] PvD (RFC 8801) is not relevant to MHMP

[Vasilenko Eduard <[e-mail]>]

Hi all,
Some people insist that PvD (RFC 8<https://www.rfc-editor.org/rfc/rfc7084>801) is the solution for MHMP.

PvD permits to:
- split one physical router on many virtual (implicitly or explicitly).
- inform the host of relationships between DNS, PIOs (and other parameters) to show what is a consistent set of information from the particular Carrier.
That's it.
"Many routers" with PvD would still be "even more routers".

If the application would use getaddrinfo(),
Then the host would still try to choose the next-hop initially (RFC6724) in a random manner (ND section 6.3.6).
If the wrong physical or virtual router is chosen then rule 5.5 RFC 6724 would restrict PIOs applicably (the wrong PIO would be chosen too).
As a result, the packet would try to access the "walled garden" from the wrong address pace, it would be dropped.

I do not see how PvD is helping MHMP at all.
Because multiplying routers number on the link is not a solution when the host is not capable to choose which one to use.
The host would still have chances to choose the wrong one (initially as the next hop, later as a PIO).
Moreover, in the situation in the picture below (2 virtual routers out of one physical), PvD would create an MHMP problem (that was absent before PvD).
Because PvD would give the host a chance to choose the wrong virtual router with the wrong PIO.
[cid:image001.jpg@01D905C4.51E65A00]
Eduard