Re: [IPv6] communicating multiple link (status) to hosts

On 21-Mar-24 15:58, Michael Richardson wrote:
> 
> {trying to start a new thread}
> 
> Lorenzo Colitti <lorenzo=40google.com@dmarc.ietf.org> wrote:
>      > And that's bad. The network does not have the capability to leverage
>      > multiple paths by using multipath protocols. Only the hosts do.
> 
>      > Hiding multihoming from the hosts using NPTv6 will prevent hosts from
>      > leveraging these protocols to improve bandwidth and resilience.
> 
>      > While MPTCP is difficult to deploy due to middleboxes, MP-QUIC does not
>      > have this problem, and interest in MP-QUIC is building. Even without
>      > MP-QUIC, even today QUIC already supports client-initiated session
>      > migration. That can be leveraged to maintain existing connections alive
>      > when one of the uplinks fails - the client can just migrate the
>      > connection to a new source address which will use a new uplink. If we
>      > hide the uplinks from the client using NPTv6, we cannot do that.
> 
> For networks which are more complex than a home network with a single LAN
> segment (no SNACk ) and two routers... how do hosts find out which egress
> routers are up/down/congested/etc.

I think the only universal answer to this is probing. Actually we learned
that from SHIM6.

      Brian

> 
> I think that this was one of the things which HOMENET failed to do.
> Yes, we could get some of this through routing protocols, but we were trying
> to keep hosts from having to speak those.
> 
> It seems like it's new work.... or never quite completed old work.
> 
> I don't think it's enough that prefixes can get withdrawn via an absense of
> the RA, and an absense of DHCPv6-PD renewal.  And many enterprises would
> probably like to do some numbering of networks via more static allocation
> rather than DHCPv6-PD. (Even I would prefer to do that at my home office)
> 
> --
> Michael Richardson <mcr+IETF@sandelman.ca>, Sandelman Software Works
>   -= IPv6 IoT consulting =-                      *I*LIKE*TRAINS*
> 
> 
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