AS13998 — SWMED

AS13998 announces 11 IPv4 prefixes covering 85,504 addresses and 1 IPv6 prefixes.

About this network

Twelve blocks decompose one range completely, and a hospital's name is misspelled in the netname that carries it.

What it's used for

• An academic medical centre's network. 85,504 addresses across 20 IPv4 prefixes plus one IPv6 prefix, with three observed BGP neighbours.

Notable

• Eleven blocks under the netname UTSWMED step down from 129.112.128.0/17 through /18, /19, two /21s, three /22s and two /23s.
• 198.215.48.0/20 uses UTSW-MHFP-B1, registered to a maternal health and family planning department.
• 198.215.96.0/20 uses UTSW-DC, and 198.215.176.0/20 uses ZLUH, registered to Zale Lipshy University Hospital.
• 198.241.16.0/20 uses the netname NETBLK-ZALE-LIPHSY.
• The IPv6 announcement is 2620:0:840::/48.
• Eighteen addresses were queried for reverse DNS and none returned a name.

Interesting

• The 129.112 blocks tile the whole range: a /17 covering the top half, then a /18 and a /19 and a descending series of smaller pieces filling the bottom half exactly. Announcing an aggregate as its constituent halves is what an institution does when different parts of the same range need different paths.
• LIPHSY transposes two letters of the hospital name that the other netname spells correctly. Both records are live, both are authoritative for their own block, and neither corrects the other.
• A single department gets its own netname and its own /20, which is over four thousand addresses for one clinical service. Universities allocate by organisational chart rather than by headcount, and the chart is legible in the registry decades later.

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

Announced prefixes

• 129.112.0.0/16
• 198.215.36.0/22
• 198.215.48.0/20
• 198.215.96.0/20
• 198.215.176.0/20
• 198.241.16.0/20
• 199.165.152.0/23
• 199.165.154.0/24
• 199.242.234.0/23
• 199.242.236.0/22
• 199.249.214.0/24
• 2620:0:840::/48

Upstream networks

• AS6922 Texas Department of Information Resources
• AS276 University of Texas System
• AS7018 AT&T Enterprises, LLC

Adjacent networks

• AS6922 Texas Department of Information Resources
• AS276 University of Texas System
• AS7018 AT&T Enterprises, LLC