On Oct 11, 2011, at 10:27 AM, Michael Richardson wrote: > >>>>>> "Fred" == Fred Baker <[email protected]> writes: > Fred> On Oct 11, 2011, at 12:05 AM, Jari Arkko wrote: > >>> That being said, if the home routers have to discover their IPv6 >>> prefix through a protocol and store it in flash, they could >>> probably do so also for a router ID. Unless there was some >>> chicken and egg problem that required the router ID for all this >>> discovery to work... > > Fred> (z)ospf requires the router to have a router id in order to > Fred> join the network, which it has to do before it can receive the > Fred> LSAs from other routers in the area to inspect their subnet > Fred> prefixes. So making the router id dependent on the prefix > Fred> doesn't make a lot of sense to me. > > Fred> While a MAC Address is not guaranteed to be globally unique, > Fred> it is intended to be; places where duplicates have been seen > Fred> tend to be manufacturing errors. From that perspective, > Fred> grabbing the least significant 32 bits from a MAC address as a > Fred> first guess seems reasonable. What one would then need to do > Fred> is > > What do we do in that rare case where the bottom 32 of the MAC are > duplicated?
Pick a random number. Note that we agree it is a rare case. If it's a router, it probably has more than one MAC Address... > Also consider that virtual switches (VMware, XEN, etc.) all pretty much > use the same set of MAC addresses. VMware has a 50: prefix that they > use, XEN has another, and did you know that 10:00:00 (curisously like > 10/8) is reserved for private use... Yes, and homes frequently use virtual switches. To be really honest, yes, it would be good for zospf - if we recommend that - to make some suggestions. That said, there is no reason for the suggestions to be normative. What OSPF requires is that the RID is unique in the area. It does not require that it be derived from any given datum. > So, it would be good for zospf text to say something about this. > I think that we can use 32-bits of MAC address in most cases. > > Fred> One obviously doesn't actually announce any LSAs using the > Fred> router ID until a unique router id is established. > > okay. > > -- > ] He who is tired of Weird Al is tired of life! | firewalls > [ > ] Michael Richardson, Sandelman Software Works, Ottawa, ON |net > architect[ > ] [email protected] http://www.sandelman.ottawa.on.ca/ |device > driver[ > Kyoto Plus: watch the video <http://www.youtube.com/watch?v=kzx1ycLXQSE> > then sign the petition. > _______________________________________________ > homenet mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/homenet _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
