AS13548 — CHARLESTON-AS

AS13548 announces 1 IPv4 prefixes covering 65,536 addresses and 0 IPv6 prefixes.

About this network

Twelve prefixes that tile a /16 exactly, without the /16 itself ever being announced.

What it's used for

• A university's network. 65,536 addresses across twelve IPv4 prefixes, three observed BGP neighbours, and no IPv6 announced.

Notable

• The prefixes run 153.9.0.0/17, two /19s, two /20s, three /21s, a /22, a /23 and two /24s.
• Laid end to end they cover the whole of 153.9, and the covering block is not announced.
• All twelve carry the same netname, CHARLESTON-NET, registered to the college.
• Eighteen addresses were queried for reverse DNS and none returned a name.

Interesting

• Announcing every piece of a block but never the block itself is a choice with consequences. It costs eleven extra entries in every routing table on the internet and buys nothing unless the pieces are going different ways, and with one netname and three neighbours they are not obviously doing that.
• The halving pattern, each prefix half the size of the one before, is what a configuration generator produces when told to split a range and never told to stop. Nobody sat down and chose a /23 at 153.9.252.
• The registry sees one object, the routing table sees twelve. The mismatch is the useful part: the campus was numbered once, decades ago, and the fragmentation happened later and separately.

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

Announced prefixes

• 153.9.0.0/16

Upstream networks

• AS2711 Spirit Communications
• AS209 CenturyLink Communications, LLC
• AS2721 CULR, LLC

Adjacent networks

• AS2711 Spirit Communications
• AS209 CenturyLink Communications, LLC
• AS2721 CULR, LLC