On 07/08/2012 16:39, Curtis Villamizar wrote: > In message <[email protected]> > Brian E Carpenter writes: > >> On 01/08/2012 15:39, Curtis Villamizar wrote: >>> In message <[email protected]> >>> Brian E Carpenter writes: >>> >>>> Excuse front posting, but... >>>> >>>>> Today there is no DHCP help in avoiding the "please reboot" messages. >>>> >>>> Don't RECONFIGURE (DHCPv6) and FORCERENEW (DHCP) cover this, in theory? >>>> They are unicast, which is a scaling issue in enterprise networks but >>>> presumably not in homenets. >>>> >>>> Regards >>>> Brian >>> >>> These only force a renew before the lease expires. For the sometimes >>> very long IPv6 leases, this is essential. For often relatively >>> shorter IPv4 leases, it is nice but not quite as essential. >>> >>> The issue is not forcing the renew to occur earlier, it is the way in >>> which a renew that changes the address is handled. Maybe its just >>> implementations taking a shortcut, but I think in practice changing >>> the IP address takes the interface down, kills all connections, >>> including listens, and then brings it back up with a new address. >> >> Really? I can't test it in my current native-IPv6-deprived state, but >> it seems to me that Windows (at least) runs happily with multiple IPv6 >> addresses on one interface, and I can't imagine that changing one of them >> will kill the others. I have to admit I haven't studied the semantics >> of RECONFIGURE closely, though. >> >> The RFC 4192 model would look a bit sick if the interfaces get reset. >> >> Brian > > Brian, > > Aliases (more than one address on the same interface)
Aliases, as you describe them, sound like a hack. I'd like to hear from Microsoft (for example) whether their support of multiple IPv6 addresses per interface is a hack or genuine. I don't care about IPv4, but the IPv6 model is very clear. You can't read the ND spec and imagine the arrival of a new address resetting sessions that use other addresses. Brian > has worked on > every OS for a decade at least. > > The issue is more what occurs when a lease is withdrawn (force to > renew and won't renew) and another lease is provided with a different > address. AFAIK most implementations take that interface down and > bring it back up. > > They do not keep the old address as an alias for some period of time > but put new connections on the new address. > > Curtis > > >> Its >>> a bit like a reboot as implemented, except the user doesn't know its >>> coming and therefore may have open TCP connections that break. >>> >>> What I've suggested is what to do on a renew that changes the address. >>> Add an alias. Until the old address has no more connections or >>> listens on the old address, keep the old address. Then remove the old >>> address. >>> >>> If someone has an open connection, ssh for example, the old address >>> could be in use indefinitely, but if the transition is weeks, then its >>> unlikely to go beyond that. For example, if someone was using ssh to >>> do a long compile on another machine, breaking the connection and >>> killing the compile would be bad. There are certain to be plenty of >>> other uses of long duration TCP connections that would have to be >>> broken in this sort of transition, unless we can also extend TCP to >>> negotiate a change to one side of the address pair. >>> >>> Curtis > _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
