[75629] in North American Network Operators' Group
Re: Stupid Ipv6 question...
daemon@ATHENA.MIT.EDU (Stephen Sprunk)
Fri Nov 19 10:55:56 2004
From: "Stephen Sprunk" <stephen@sprunk.org>
To: "Dan Mahoney, System Admin" <danm@prime.gushi.org>
Cc: "North American Noise and Off-topic Gripes" <nanog@merit.edu>
Date: Fri, 19 Nov 2004 09:36:11 -0600
Errors-To: owner-nanog-outgoing@merit.edu
Thus spake "Dan Mahoney, System Admin" <danm@prime.gushi.org>
> I'm having trouble wrapping my head around ipv6 style suffixes -- does
> anyone have a chart handy? How big is a /64, specifically?
Subnet sizes work a bit differently in IPv6 due to autoconfiguration; nearly
all subnets are expected to be /64, which can hold up to
18,446,744,073,709,551,616 hosts. A /48, the minimum assignment to end
sites (unless proven to need only a single /64), comprises 65,536 subnets.
A /32, the minimum allocation to ISPs, comprises 65,536 /48s. Of course,
the minimum allocation sizes may be changed (up or down) in the future by
RIR policy actions, and ISPs or end-sites can get shorter prefixes with
proper justification.
/127 prefixes are assumed for point-to-point links, and presumably an
organization will divide up a single /64 for all ptp links -- unless they
have more than 9,223,372,036,854,775,808 of them.
S
Stephen Sprunk "God does not play dice." --Albert Einstein
CCIE #3723 "God is an inveterate gambler, and He throws the
K5SSS dice at every possible opportunity." --Stephen Hawking
