Re: Stateless Prefix Delegation I-D updated (draft-savolainen-stateless-pd)

[Ole Troan <otroan@employees.org>]

Teemu,

> Yes, number of messages is not the issue. However, with DHCPv6 PD the DHCPv6 server has to identify the RR, while in stateless the same ISP prefix could be communicated to all requesters. Nevertheless, your proposal is very interesting and we need to think about it. In a way there could be very lightweight DR at the gateway, right? 

indeed. only difference is that you compute the prefix on the DR instead of at the RR.

> Have you seen also http://tools.ietf.org/html/draft-krishnan-intarea-pd-epc-00 ? With DHCPv6 PD there's the issue of not being able to use one /64 on the WAN from the delegated space. On the other hand, not having a global /64 prefix on the WAN at all (unnumbred model) probably would be too big change for the 3GPP. Any thoughts about this issue? 

I think this violates the contract the RR has with the DR. you cannot delegate / aka give something to someone and then take back a bit of it. even though many managers delegate this way. ;-)

you could perhaps resolve this by making a modified PD option which carry a representation of the address block which allows for this.

or you could just split the block in two. e.g the route on the DR is a /55, you delegate the bottom /56 and you use the top one for the linknet /64.

> Binding to L2 would indeed mean that, unless somehow kept the same during cellular network reconnection e.g. after unexpected network disconnect (NEMO is then for true network mobility..). I'll note this. 

cheers,
Ole