LÉVAI Dániel @ 2016-01-31T14:10:21 +0100: > Stuart Henderson @ 2016-01-30T23:01:54 +0100: > > On 2016-01-30, LÉVAI Dániel <[email protected]> wrote: > > > Hi! > > > > > > My ISP recently enabled ipv6 on their network, and started sending > > > router advertisements (offering a /64 prefix) on their pppoe end. So now > > > I have an autoconf'd v6 address on my pppoe0 device (yay!), and I wish > > > to set my in-home devices a v6 address each. > [...] > > You aren't supposed to have addresses within the same /64 on more than > > one interface. > > > > The normal method is that you get an address for the PPP interface using > > SLAAC autoconf (as you have now), and request one or more *additional* /64s > > using DHCPv6-PD (prefix delegation) - one per interface. The DHCPv6 client > > assigns to "downstream" (client-facing) interfaces from this assignment, > > and you would use rtadvd to advertise the prefix (and possibly other > > information) to clients. > > > > There is no software in OpenBSD base to handle prefix delegation. > > I recommend "dhcpcd" from packages and I've added a pkg-readme with a > > minimal setup to handle just this (it is also a full-featured DHCP client > > for v4, but I'm personally only using it for v6). Unlike some alternatives > > it is actively maintained upstream by a responsive developer. [...] > re1: IAID <> > pppoe0: IAID 00:00:00:01 > pppoe0: IAID 00:00:00:02 > pppoe0: no useable IA found in lease > pppoe0: dhcp6_readlease: /var/db/dhcpcd-pppoe0.lease6: No such process > pppoe0: soliciting a DHCPv6 lease > athn0: IAID <> > athn1: IAID <> > pppoe0: ADV 2a01:36d:300:<>::/64 from fe80::5dd9:bcc7:cbab:8bb8 > pppoe0: REPLY6 received from fe80::5dd9:bcc7:cbab:8bb8 > re1: adding address 2a01:36d:300:<1>::1/72 > athn0: preferring 2a01:36d:300:<1>::1/72 on re1 > athn1: preferring 2a01:36d:300:<1>::1/72 on re1 > pppoe0: renew in 302400 seconds, rebind in 483840 seconds > pppoe0: adding reject route to 2a01:36d:300:<>::/64 via ::1 > athn0: adding route to 2a01:36d:300:<1>::/72 > forked to background, child pid 346 [...] > Do I understand it correctly, that this should delegate each interface a > /72, while leaving pppoe0's autoconf[privacy]'d addresses intact?
So turns out, that if I request anything other than sla_id 0 or 1, I get another subnet, but with a /72 prefix. Also, using: ia_pd 1 re1/1 athn0/2 athn1/3 ... resulted in the same subnet/prefix sent to me, for all interfaces. For some reason I had to increment the sla_ids by 4 to get another subnet. So: ia_pd 1 re1/1 athn0/4 athn1/8 ... actually worked, and got three different subnets, but all came with a /72 prefix. And for some other reason, none of my devices (Linux, Android, Chromecast...) would accept a /72 address advertised, so although they all got a reply for their rtsol, they ignored it... I'm now just requesting one PD, with sla_id 0, assigning that to re1, bridging the athns and re1 together, and running rtadvd(8) on re1. Daniel -- LÉVAI Dániel PGP key ID = 0x83B63A8F Key fingerprint = DBEC C66B A47A DFA2 792D 650C C69B BE4C 83B6 3A8F
