On 29 dec 2007, at 21:11, Brian E Carpenter wrote:
For instance, if an IPv6 router sits on top of two layers of layer 2 aggregation devices, the IPv6 router sends out router advertisements with prefix 2001:db8:31::/64.
Why do you say /64? The model is supposed to be that SOHO subscribers get at least a /56.
This is when the user's machine(s) directly get RAs from the ISP. In that case it has to be /64 or stateless autoconfig won't work. If they want more than a /64 they'll need an IPv6 router and, presumably, DHCPv6 PD to request a prefix.