Re: [IPv6] RFC 6724 shouldn't prefer partial reachability over reachability

Ole Trøan <otroan@employees.org> Tue, 21 November 2023 13:01 UTC

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From: Ole Trøan <otroan@employees.org>
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To: Ted Lemon <mellon@fugue.com>
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Subject: Re: [IPv6] RFC 6724 shouldn't prefer partial reachability over reachability
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On 21 Nov 2023, at 13:45, Ted Lemon <mellon@fugue.com> wrote:


So the second tier routers would be too stupid to forward packets through the correct exit router? Even though we have a clear rule for how to do it?  That seems like a bug in need of fixing, not an impossible problem. 

Alternative explanation is that you are too stingy to pay to upgrade the forwarding engines. 
Most routers can do this with policy routing, but I am not aware of any efficient SADR lookup yet. 

Nice try, trying to deflect the problem to the network. :-)
Updating every host stack and every application seems completely infeasible. 

I have tried MPMH at home over the last decade and a half and as far as I can tell we have not gotten any closer. 

At this point MPMH seems mostly like a distraction. Let’s focus on the mechanisms that can be made to work now. 

O. 



Op di 21 nov 2023 om 06:45 schreef Ole Troan <otroan=40employees.org@dmarc.ietf.org>
> The more I think about it, the more I am thinking that it may be a deployable solution for multihoming, with all of the details in appropriate stages of hand waving.

The more I think about it, the less I think it is deployable.

MHMP:
- Rule 5.5 support in all hosts (which as Lorenzo alluded to is complicated)
- Application changes to handle failover
- No multi-homing policy available to the network
- Only works when hosts are directly connected to exit routers. _Any_ other topology requires routers to do SADR or SADR like behaviour

I don’t see any realistic way where MHMP can be made deployable.

I’d rather we focus on the multi-homing mechanisms that could work.

Cheers,
Ole



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