IPv6 addressing for core network
sam at spacething.org
Wed Feb 9 07:35:03 CST 2011
On 9 Feb 2011, at 09:48, sthaug at nethelp.no wrote:
>> 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.
Can you elaborate on this? What's the ping-pong problem?
Sam (who's experience is pretty much mostly ethernet)
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