> On 16.8.2015, at 14.40, Juliusz Chroboczek <[email protected]> > wrote: > When an HNCP router is restarted, the prefixes it allocated to a link are > "adopted" by neighbouring routers; if the router then restarts, it will > agree to the prefixes advertised by its neighbours, which avoids > renumbering. > > Unfortunately, this only applies to link with multiple HNCP routers: on > a stub link, a random prefix will be chosen every time we are restarted, > since there are no neighbours that can maintain the state for us. I can > see the following solutions: > > 1. store the chosen prefix in stable storage (but stable storage sucks); > > 2. make an initial choice that is a hash of the interfaces MAC address > (I believe that this is what hnetd does);
hnetd does 1+2 (although not sure if OpenWrt version stores 1 to ramdisk currently or not at all by default, cough). > 3. snoop ND/ARP traffic and intuit a suitable prefix. This may be tricky, at least in case of pure v6, as the ND target will be probably link-local address? I guess given multiple nodes on the link, ND would be enough, but I suspect for this to be generic in case of v6 you would have to snoop ‘everything’ and assume first assigned prefix source address that is not published by anyone else within HNCP is one that actually was on the link. With v4, ARP snooping is probably enough to determine the old prefix. Cheers, -Markus _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
