prefixlen of IPv6 over PPP

[Nagae Hidetake <nagae%eagan.jp@localhost>]

Hello, NetBSD users.
I have a question about prefixlen of IPv6 over PPP.

My ISP provides IPv6 tunneling service over PPTP
(Point to Point Tunneling Protocol). 
Supported platform of clients is Windows Vista.
IPv6 address is assigned with Router Advertisement.

I'm trying to use this service with NetBSD/i386 5.0.1.
PPTP tunnel is successfully opened with pkgsrc/net/pptp as below.
(ppp1 is a PPTP tunnel)

ppp0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
        inet aaa.aaa.aaa.aaa -> bbb.bbb.bbb.bbb netmask 0xffffff00
        inet6 fe80::xxxxx:xxxx:xxxx:xxxx%ppp0 ->  prefixlen 64 scopeid 0x5
ppp1: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1500
        inet6 fe80::yyyy:yyyy:yyyy:yyyy%ppp1 -> fe80::zzzz:zzzz:zzzz:zzzz 
prefixlen 128 scopeid 0x6

Next, I call rtsol command and the router returns rtadv.
But my NetBSD box ignores it.
It seems going into the path 'in6_ifadd: wrong prefixlen for %s'
of src/sys/netinet6/nd6_rtr.c.

I guess that the problem is prefixlen of ppp1.
All 128 bits of link-local address are prefix.
On the other hand, prefixlen of IPv6 over PPP looks like set always
128 in 'sif6addr' of src/usr.sbin/pppd/pppd/sys-bsd.c.

Is the prefixlen of ppp1 (128 bit) right?


-- 
Nagae Hidetake          nagae%eagan.jp@localhost
                        http://www.eagan.jp/nagae/