On 25/10/2012 17:03, Alexandru Petrescu wrote: > Hello Brian, > > Thank you for the email. Please see below some comments. > > Le 23/10/2012 14:19, Brian E Carpenter a écrit : >> I realised while reading this draft that I just don't understand >> its operating model. It refers to the "requesting" router supplying >> Prefix Collection and Prefix Information to the delegating router: >> >>> When requesting prefixes a requesting router MUST add for each >>> requested prefix a Prefix Information in the Prefix Delegation >>> option >>> of the RS message. >> >> However, by definition the requesting router doesn't know what prefix(es) >> it will be given. So surely all it can ask for is N unspecified prefixes >> of given lengths? > > Right, this may be wrong. > > I checked the document and it misses, I think, something important. The > first and most naïve request of a prefix by a Requesting Router should > have all bits zero and maybe the prefix length 0, or around 64. > > Would this be ok?
Wouldn't the request typically be for a /48 or a /56? If I'm renumbering an existing network, I will want a prefix that is no longer than what I already used. I wonder whether an expensive BMW will always request a shorter prefix than a Nissan Versa. >> It also says: >> >>> PC_ID: An unique identifier of the Prefix Collection. The >>> PC_ID MUST be unique among all PC_ID known by the >>> requesting router. >> >> How can the requesting router provide this in its REQ message? By >> guessing? > > I think the PC_ID is generated by the requesting router (not by the > delegating router), just as with IA_ID, no? Ah yes, I simply misread the text, sorry! Brian > >>> 11. Security Considerations >>> >>> TBD >> >> OK, but since a vehicular network is open to any one of millions of >> unmanaged devices, this will need to be *very* convincing, especially >> in preventing DOS. > > I agree. We currently try to understand these threats, and especially > how they are specific to ND, to prefix delegation and to new flags we add. > > We may add more threat descritpion in the next versions of the draft. > > Alex > >> >> Regards >> Brian Carpenter >> >> >> > > -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
