2001:250:21c::/48

Currently announced by AS24350 CERNET2 IX at Beijing University of Posts and Telecommunications, in the routed prefix 2001:250:21c::/48.

Current ASN: AS24350; CERNET2 IX at Beijing University of Posts and Telecommunications
Routed prefix: 2001:250:21c::/48; Most specific route covering this prefix
ASNs over time: 2; 2 announcement records
RIR allocation: APNIC; China · 2001:250::/35

Routing data · Nov 1, 2026, 22:23 UTC

ASN historyEvery routed prefix covering 2001:250:21c::/48

Prefix	ASN	Name	Registered country	First seen (UTC)	Last seen (UTC)	Status
2001:250:21c::/48	AS24350	CERNET2 IX at Beijing University of Posts and Telecommunications	China	2026-10-27 06:18	2026-11-01 22:23	Announcing
2001:250::/32	AS23910	China Next Generation Internet CERNET2	China	Before monitoring	2026-11-01 22:23	Announcing

No more specific routes inside this prefix.

Detected (UTC)	Prefix	Change	ASN	Name	Previous ASN	Country
2026-10-27 06:18	2001:250:21c::/48	New announcement	AS24350	CERNET2 IX at Beijing University of Posts and Telecommunications	—	China

From the RIRs’ delegated statistics files. Shows where the addresses are registered, not where they are used.

Every 2 hours ASNBase takes the bgp.tools global routing table (prefix → origin ASN) and compares it with the previous one. The detected time is the time of that comparison; the actual change can be up to about 2 hours earlier.
Only routes seen by more than 100 bgp.tools peers are listed as changes; routes with less visibility are only kept in the history.
A new announcement counts only if it is still in the next routing table, and a withdrawal only if the prefix is missing from two tables in a row, so short flaps are ignored.
ASNBase has been monitoring since 2026-10-19. “Before monitoring” under “First seen” means the route was already announced when monitoring started; the earlier date is unknown.
Prefixes first seen during the first day of monitoring do not count as new announcements: most of them were simply missing from the table at the moment monitoring started.
Countries and regions follow the ASN’s registration, not the actual location of the IP addresses.