Steven, SLAAC is prohibited for using in DOCSIS networks, router advertisements that allow SLAAC must be ignored by end-devices, therefore DHCPv6 is the only way of configuring (if not talking about statical assignment). I have seen at least Windows7 handling this properly in its default configuration: it starts DHCPv6 negotiation instead of auto-configuration.
Dmitry Cherkasov 2011/11/29 Steven Bellovin <s...@cs.columbia.edu>: > > On Nov 28, 2011, at 4:51 52PM, Owen DeLong wrote: > >> >> On Nov 28, 2011, at 7:29 AM, Ray Soucy wrote: >> >>> It's a good practice to reserve a 64-bit prefix for each network. >>> That's a good general rule. For point to point or link networks you >>> can use something as small as a 126-bit prefix (we do). >>> >> >> Technically, absent buggy {firm,soft}ware, you can use a /127. There's no >> actual benefit to doing anything longer than a /64 unless you have >> buggy *ware (ping pong attacks only work against buggy *ware), >> and there can be some advantages to choosing addresses other than >> ::1 and ::2 in some cases. If you're letting outside packets target your >> point-to-point links, you have bigger problems than neighbor table >> attacks. If not, then the neighbor table attack is a bit of a red-herring. >> > > The context is DOCSIS, i.e., primarily residential cable modem users, and > the cable company ISPs do not want to spend time on customer care and > hand-holding. How are most v6 machines configured by default? That is, > what did Microsoft do for Windows Vista and Windows 7? If they're set for > stateless autoconfig, I strongly suspect that most ISPs will want to stick > with that and hand out /64s to each network. (That's apart from the larger > question of why they should want to do anything else...) > > > --Steve Bellovin, https://www.cs.columbia.edu/~smb > > > > > >