> Is there a NANOG FAQ we can add this to? > > > 1- Use Public Ipv6 with /122 and do not advertise to Internet > > 2- Use Public Ipv6 with /127 and do not advertise to Internet > > The all zeros address is the all routers anycast address so on most non-Cisco > routers you can't use it, ruling out /127. The top 128 addresses in any > subnet are also reserved anycast addresses although they don't do much in > practice. So the longest prefix length you should use is /120 and only use > addresses 1 - 127.
A /127 mask is still the best way to handle real point-to-point links like SDH/SONET today, to avoid the ping-pong problem. Works fine with Cisco and Juniper, not tried with other vendors. Steinar Haug, Nethelp consulting, sth...@nethelp.no