AS15118 — SIUMED

AS15118 announces 1 IPv4 prefixes covering 4,096 addresses and 0 IPv6 prefixes.

About this network

A medical school routing two slices of its parent university's address space under its own AS number.

What it's used for

• A medical school's network. Two IPv4 /21 blocks announced from the United States, no IPv6, and two observed BGP neighbours.

Notable

• Both blocks are registered to the parent university, not to the school, under the shared netname SIU-NET.
• Both fall inside the same 131.230 range that the parent institution's own AS number announces, so one allocation is split across two autonomous systems.
• Two of six sampled addresses answered, in the form ws254.net229.siumed.edu: a host label, then a separate label naming the subnet by its third octet.
• That domain is the school's own, distinct from the domain the parent university publishes.

Interesting

• The subnet-as-a-label convention is unusual and useful. Most address-derived names flatten the whole address into one label; this one keeps the network and the host separate, so the name mirrors the structure of the addressing rather than just its digits.
• Two AS numbers over one registered allocation is the interesting shape. The registry sees a single university holding one allocation; routing sees a teaching hospital with its own transit and its own failure domain. Neither view alone describes the institution.
• The school publishes reverse names under its own domain while the addresses stay in the parent's name, so the identity in DNS and the identity in the registry disagree by design.

This description is AI-generated, best-effort context — not authoritative, and provided without any guarantee of accuracy.

Announced prefixes

• 131.230.224.0/20

Upstream networks

• AS62943 Missouri Network Alliance, LLC
• AS6325 Illinois Century Network

Adjacent networks

• AS62943 Missouri Network Alliance, LLC
• AS6325 Illinois Century Network

Routing security

• RPKI: 3 valid, 0 invalid and 0 not-found announcements; 4 ROAs.
• ASPA: 3 authorised providers.
• IRR: 100% of announcements registered; 7 route objects.
• Listed in as-sets: AS-BLUEBIRD, AS-HURRICANE, AS-ICN-CUSTOMERS, AS-TRANSROUTE-SPEC, AS62973:AS-CUSTOMERS, AS6325:AS-ICN-HIGHERED.