Am 30.08.2025 um 18:54:15 Uhr schrieb nanog--- via NANOG:
2400::/12 is larger than any prefix allocated to a network. In fact it's a prefix allocated to ARIN, which sub-allocates prefixes to various North American networks.
Isn't 2400::/16 used in the APNIC area? Various Asian countries use networks in that area. According to whois, 2400::/20 is allocated to South Korea. KRNIC is not an ISP but a National Internet Registry similar to APNIC. [ Network Information ] IPv6 Address : 2400:0000::/20 Organization Name : Korea Telecom Service Name : KORNET Address : Gyeonggi-do Bundang-gu, Seongnam-si Buljeong-ro 90 Zip Code : 13606 Registration Date : 20050601 Name : IP Manager Phone : +82-2-500-6630 E-Mail : kornet_ip@kt.com - KISA/KRNIC WHOIS Service -
Network operators can announce whatever they want to their customers. It's not uncommon for some customers to get summarized routes. Some ISP far away from America could be telling its customers "yes, I know how to get to North America".
Summarizing routes is different to that - not all prefixes from that net are announced.
This radar tool seems to be showing what ISPs tell it, without filtering such ISP-specific routes. You can see other "invalid" routes such as /128 routes in the same tool. Such routes won't propagate across the whole internet, by convention, but there's no rule that a single ISP can't use them.
Do they use that to reduce the amount of routing table entries in routers that are far away from such networks? -- Gruß Marco Send unsolicited bulk mail to 1756572855muell@cartoonies.org