Using IPv6 with prefixes shorter than a /64 on a LAN

George Bonser gbonser at
Tue Jan 25 22:47:36 CST 2011

> From: Adrian Chadd 
> Sent: Tuesday, January 25, 2011 8:37 PM
> To: Owen DeLong
> Cc: nanog at
> Subject: Re: Using IPv6 with prefixes shorter than a /64 on a LAN
> (Top-posting because the whole message is context. Oh, and I'm lazy.)
> I do indeed love it when people break out IPv6 addressing as
> "there's so many addresses, we'll never ever go through them!"
> Sure, if they're only used as end-point identifiers.

Yeah, at some point v6 IP addresses might be used for something
completely different.  For example, rather than using a cookie to
balance through a load balancer to get back to a server in a "sticky
session", maybe you are redirected directly to an IP address on the
server that represents your session.  The IP address could be
provisioned dynamically on the server as required, the user hits the
main URL and is "redirected" to the unique IP address representing their

If you have a 64-bit address, each active session can easily be given
its own unique IP.  I can see requirements at some point for servers to
be able to handle thousands of IP addresses per interface.

More information about the NANOG mailing list