AS21520 Instituto Tecnologico Autonomo de MexicoITAM

Every prefix observed with AS21520 as its origin, checked against RPKI and the IRR. Problems sort first.

Signed statements by address holders that AS21520 may originate these prefixes, up to the maximum length shown.

No ROA names this AS as an authorised origin.

ROA-based and RPKI-valid-only prefix lists for routers are on asn.ipinfo.app.

No ASPA record This network has not published an ASPA object. ASPA lets a network sign the list of its transit providers, so routers can reject paths that route through anyone else (route leaks). Only a few thousand networks publish one so far, so its absence is normal.

Route objects naming AS21520 as origin, across RADb, the RIR registries, ALTDB and NTTCOM. Objects that are registered but not announced come first: a stale object lets anyone who can spoof this origin through an IRR-built filter.

The as-set is what upstreams expand to build this network's customer filter. Sets that list AS21520 directly show who expects to carry it.