Re: [homenet] Which IP addresses must be avoided?

Joe Touch <touch@isi.edu> Wed, 18 May 2016 19:00 UTC

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To: otroan@employees.org, Juliusz Chroboczek <jch@pps.univ-paris-diderot.fr>
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From: Joe Touch <touch@isi.edu>
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Date: Wed, 18 May 2016 11:49:52 -0700
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Cc: Markus Stenberg <homenet@ietf.org>, "Bless, Roland \(TM\)" <roland.bless@kit.edu>
Subject: Re: [homenet] Which IP addresses must be avoided?
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On 5/18/2016 1:02 AM, otroan@employees.org wrote:
> Juliusz,
>
>>> https://tools.ietf.org/html/rfc5453
>>> provides an answer w.r.t. IPv6.
>> Do I need to avoid these addresses when assigning a /128 or a /127?
> no. if you assign a /128, that is a single address, the length of the IID is zero.

A /128 seems like it indicates that the entire address is the IID.
There's no "network" part left if it refers to a single address.

> The case of /127 is a little trickier, since then one end will get the subnet-router anycast address.
> as long as both ends of the /127 agree, that's not a problem.

See RFC 6164. It's supposed to be standard to allow use for 2 addresses
on a point-to-point link.

Joe