Re: Comments on draft-ietf-multi6-multihoming-requirements-00

[Greg Maxwell <gmaxwell@martin.fl.us>]

On Wed, 4 Apr 2001, Joe Abley wrote:

> I think the compromise that Brian suggested earlier (that the multi-
> homing strategy *allows* changes above the IP layer to facilitate
> enhanced behaviour over re-homing events, but doesn't *require* them)
> is sensible.

Right. This makes sence. Multihoming should be work at least 'work' for
legacy apps. 
 
> If the enhanced behaviours are compelling, they should obtain
> widespread support as easily as might be expected for transport-layer
> changes.

There should be little to no hardware costs to support the transport
enhancements on most hosts needing the full benifits of multihoming.

I wish the same could be said about IPv6 and routers. :(

> In the case of session stability, I think the enahanced behaviours
> are extremely desirable and will need to be designed and deployed
> quickly in response to user-demand; otherwise we risk economic
> pressure from the user population pushing for a return to hole-
> punching and deaggregation.
> 
> This is evidently a contentious issue, however, and absent of any
> hard data about the prevalence of long-held TCP sessions and their
> behaviours in reaction to re-homing events I don't think we should
> delay the layer-3 recommendations unnecessarily.
> 
> Whatever we end up doing overall, the rational approach at the IP
> layer is to eliminate the current fashion for long prefix
> advertisements.

Right. This is IPv6 we're talking about. It costs less to replace the
transport then the network, and the majority of people installing IPv6 are
not going to be earliey adopters, but the time a majority are moving onto
IPv6 it is quite reasonable to expect that the transport enhancements will
already be accepted and a standard part of the IPv6 upgrade process.