IPv6 network policies

[michael.dillon at bt.com]

> For IPv6 it seems to me we have two camps with different philosophies:
> 
> - The ping pong problem *should* be solved in IPv6, and it 
> can be solved if the vendors do <X>.
> 
> - The ping pong problem doesn't need to be solved in IPv6 
> since using a /127 works just fine. So let's bless the /127.

What about the pragmatic camp? Reserve a /64 for every PTP
link and actually configure a /127 (or /126). This has the
advantage of shorter and more memorable prefixes, i.e.
2001:DB8:1:77::/64 would be reserved and 2001:DB8:1:77::/127
would be configured. 

> Given that 
> 
>    http://tools.ietf.org/html/draft-ietf-ipngwg-p2p-pingpong-00
> 
> is from 2001, and nine years later there are still 
> large/important vendors that have this problem - is it likely 
> that it *will* be solved in the manner suggested by this draft?

It's still early days for IPv6. As more people deploy it and
feedback their needs to vendors, more things will get fixed
and adjusted. There has been a sad tendency for people to stumble
upon a problem with v6 and to use that as an excuse for not
deploying, without escalating the stumbling block to where it
can be resolved. Now that people are being forced to deploy due
to IPv4 runout, they are more likely to get the message to vendors
that something needs to be fixed.

If and when ping-ponging is fixed, anyone who has reserved a /64
for each PTP connection can switch to configuring the whole
/64 if it simplifies Operational Support Systems.

Configure it how you want, just don't back yourself into a corner
trying to achieve some mythical efficiency that just doesn't exist
in IPv6, and is unlikely to cause problems until your
great-grandchildren
are running the network.

--Michael Dillon