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) 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 The issue is more what occurs when a lease is withdrawn (force to renew and won't renew) and another lease is provided with a different address.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
