In message <[email protected]> Mark Townsley writes: > On Oct 12, 2011, at 6:23 PM, james woodyatt wrote: > > > On Oct 12, 2011, at 1:52 PM, Curtis Villamizar wrote: > >> > >> A router should not start handing out PD or even IPv4 NAT space until > >> it gets and address from elsewhere. > > Every IPv4 home router I have ever seen hands out RFC 1918 space > regardless of whether an ISP connection is active. This is needed, if > nothing else, to manage the router with the classic IPv4 literal in a > web browser (yes, this could be done with link-local, but that's not > something you can hard-code in documentation or a sticker on the side > of the box).
For IPv4, routes can be installed for non-local link-local addresses or ULA prefixes can be used if no address is available. The practice of using 192.168.1.1 should be changed. The change could be as simple as a DNS mapping of "local-router." to the link local addres. A DHCP host query would get an offer of a DNS server which would respond with a DNS entry for local-router. The dot is significant though if omitted the domain search list would be used with the last entry presumed blank. As long as there is no "local-router." TLD glogally defined this should be OK. A user with multiple routers on the subnet can just paste the link-local address in place. Maybe routers can look for others and offer a "local-router-N." for each other router detected. Then "http://"local-router."; or "http://"local-router-N."; can be used if the user does need to do any config. There could also be some improvement on the common practice of allowing a default password on any port except the designated uplink. In an auto-config router this would never change. Perhaps this could be enabled only 10 seconds or so after power up if the factory default password is in place, at least limiting the exposure. This could fit in the manual and maybe even on a sticker. But yes, IPv4 must hand out a PI address if it has nothing else to hand out. > > Some routers need to do this, i.e. home routers where service > > providers charge prohibitive rates for always-on Internet dial-tone > > and expect subscribers to connect on demand and disconnect after an > > appropriate idle time. > > > > For IPv4 today, these routers typically use PPPoE on the WAN and > > they often handle this by assigning RFC 1918 address to the LAN > > hosts and using DNS queries to signal PPPoE to establish the WAN > > link. > > > > For IPv6, I'm not sure what they should do, but I have some ideas. > > Basically, the router should advertise as a default router with a > > single ULA prefix and a DNS server at the router's ULA interface > > address with RFC 6106 and optionally RFC 3736. When the DNS query > > signals PPPoE to establish the WAN link, the DHCPv6 client will ask > > for a IA_PD and update the prefix advertised on the LAN > > accordingly. > > "Update" or just advertise the new global prefix alongside the ULA? > > - Mark I meant "update" in the context of refreshing the IA_PD request at the provider DHCP server that handed it out the last time the demand circuit was up. If the prefix was held while the demand circuit was unused and down, then no change is needed on the homenet side when the demand circuit comes back up. Curtis _______________________________________________ homenet mailing list [email protected] https://www.ietf.org/mailman/listinfo/homenet
