IPv6 PPP procedures?

[Nick Sayer]

I have begun experimenting with IPv6 PPP using Brian Somers' latest BSD 
PPP sources. I am at the point where PPP connections come up and a 
link-local address is negotiated for each end, vis:

tun0: flags=8051<UP,POINTOPOINT,RUNNING,MULTICAST> mtu 1398
        inet6 fe80::1387:a573%tun0 --> fe80::1422:8917%tun0 prefixlen 
128 scopeid 0x6

As soon as it is in this state, I can also use 'iface add' to assign 
routable addresses to both sides manually to get

        inet6 3ffe:1200:301b:3::1 --> 3ffe:1200:301b:3::2 prefixlen 128

at which point route6d on the "server" makes the endpoint reachable and 
everything is good and righteous.

The problem is that it requires more or less manual intervention to do 
all of that.

Is there a spec for what a PPP connection is supposed to do once the 
link-local addresses are established? Shouldn't the "client" at that 
point perform a router solicitation to determine the prefix on its 
endpoint or something?