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[IPv6]Re: New draft: "The IPv6 Loopback Address Prefix"

Michael Siegenthaler <michael@msigi.net> Wed, 03 December 2025 04:58 UTC

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From: Michael Siegenthaler <michael@msigi.net>
Date: Tue, 02 Dec 2025 20:57:55 -0800
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Subject: [IPv6]Re: New draft: "The IPv6 Loopback Address Prefix"
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First time posting, but I'd like to chime in with a use-case that
could benefit from an expanded loopback range.

I have a software project (BGP library) that matches incoming
connections to a config by their src+dst IP addresses. In the unit
tests I run multiple instances on a single host.

With IPv4 I can bind to 127.0.0.2, 127.0.0.3, and so on, as an
unprivileged user with no special system configuration. But in IPv6
there's only ::1.

In my view we need something that's as easy to use as another TCP/UDP
port. Expanding ::1/128 to a /96 seems natural.

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