Re: IPv6 Default Allocation - What size allocation for Loopback Address

[William Herrin <bill () herrin us>]

On Sat, Oct 11, 2014 at 1:41 AM, Faisal Imtiaz <faisal () snappytelecom net> wrote:
> A follow up question on this topic..
>
> For Router Loopback Address .... what is wisdom in allocating a /64 vs /128 ?
> (the BCOP document suggests this, but does not offer any explanation or merits of one over the other).

Hi Faisal,

One of the viewpoints held by some in the IETF is that an IPv6 address
is not 128 bits. Rather, it is 64 bits of network space and 64 bits of
host space. I'm told this viewpoint is responsible for the existence
of a 128 bit address instead of IPv6 using 64 bit addresses.

If you follow that reasoning, the subnet mask should always be /64, no
matter where the address is assigned.

There are, of course, excellent operational reasons not to religiously
follow that plan.

Regards,
Bill Herrin



-- 
William Herrin ................ herrin () dirtside com  bill () herrin us
Owner, Dirtside Systems ......... Web: <http://www.dirtside.com/>
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