jgg7

What's missing is the charm. In general, AI-generated visual content tends to have a very sterile look to it. The only image in said thread that looks even remotely decent to me is the one of a canyon/bridge. The rest are what I'd classify as voids.

I see you were not part of the "old internet".

Yeah, I'm familiar with the original companies that have /8 allocations per IANA. I started using the 'net in 1989.

I'm also aware many of those places have either refused to relinquish space, or have done so but have no more to give back. Quoting Doug Barton, former manager at IANA, July 2015: "... Many orgs did give back space and/or swap allocations. But that well ran dry long ago" (if you need a reference link for that quote, let me know).

A recent example of relinquishing space is 18.0.0.0/8 (previously MIT) as of April 2017, which now has many /16 and /24 segments delegated to companies such as Comcast (ex. 18.10.0.0/16), Amazon (ex. 18.145.0.0/16), and Akamai (ex. 18.255.255.0/24), while many larger portions still reside with MIT (ex. 18.128.0.0/12, 18.0.0.0/9, 18.144.0.0/16).

My point of giving examples: note all the /16s. If you need further examples, refer to IANA's Recovered Address Space document and note the subnet sizes (many are much smaller than a /16): https://www.iana.org/assignments/ipv4-recovered-address-spac...

Every little bit counts.

Your understanding is mostly correct. Whether or not traffic directed to any of the /24s involved "would have eventually reached the destination" is undetermined (and possibly irrelevant), meaning it's both possible and not possible. We simply don't know. Speaking strictly about "internet routing" (BGP in this case), it is 100% possible for an announcement to send traffic through an AS which literally dumps it on the floor -- it's happened many times over the years (the Pakistan/Youtube one was noticed by many): https://en.wikipedia.org/wiki/BGP_hijacking#Public_incidents

The question is whether or not the /16 (of which most of the advertised/withdrawn /24s make up) was used by actual devices, or if it's address space NTT has yet to use. If it is assigned to NTT but unused space, then effectively no harm done. If it's actually used IP space, then that would be very inappropriate.

AS15562 appears to be an employee of NTT out of the Netherlands. I can't tell if AS15562 is for personal or work, maybe both: http://bgp.he.net/AS15562

I couldn't care less about the IPv6 prefixes, but the IPv4 ones are all /24s made from 209.24.0.0/16, which is registered to NTT (AS2914). 209.24/16 is publicly announced (and has been for a very long time), and is routed through NTT Amsterdam routers.

I haven't looked at BGPlay to review all the data, but it looks like many of the /24s that make up that /16 were individually announced through AS15562, then later withdrawn, gradually over 4 months, to make said graph. I would hope this would be unused v4 space. That AS announced almost 98% of a /16 (probably 209.24/16): https://stat.ripe.net/AS15562#tabId=routing

Another user voiced their concerns, particularly if it was actively used: https://news.ycombinator.com/item?id=14621859 -- there's no way any of us could know this; NTT would be authoritative, and jwhois -h rwhois.gtt.net.net -p 4321 209.24.0.0/16 doesn't give any clues.

While the antic made me smirk, it doesn't (publicly) "look good" when we're living in a world that lacks (or has greatly limited) v4 space. What this says is: "NTT has a /16 they're fooling around with publicly", even though it (presumably) is harmless.