Siguza6d ago
So one sixteenth of the entire IPv4 space, 240.0.0.0/4, is reserved for "future use". When exactly is this future gonna be? 🤨
Show threadJason Stangroome
@siguza I wondered the same thing a little while ago and discovered this:
https://blog.benjojo.co.uk/post/class-e-addresses-in-the-real-world
Reclaiming IPv4 Class E's 240.0.0.0/4

Mar 28 at 8:15amWeb
Show threadSiguza6d ago
@jstangroome oh great, half the routers don't support it? Fucking hell, network gear is absolute shit...
Show threadNicolás Alvarez5d ago
@siguza @jstangroome I think the specs never said what "reserved" means. Until the "future use" is actually defined, are you supposed to drop packets, or accept them and forward them as if they were regular addresses? In hindsight, the former makes it impossible to introduce a new use for it, but... specs didn't say.
Show threadJason Stangroome5d ago

@nicolas17 @siguza given the official definition of the IP space, I appreciate it is a reasonable default for routers to drop packets using those IPs to mitigate abuse.

Unfortunately whether it's a router firmware update, or a trivial configuration toggle, there are going to be router operators unwilling to make those changes.

And then there's the end-of-support router hardware that would need replacing.

*Sigh*.