AS15129 GENESEO-IL

Six netname conventions, three reverse-DNS schemes, and a college's block in the middle.

What it's used for

• A rural telephone company's network. Twelve IPv4 prefixes and one IPv6 /32 announced from the United States, with eight observed BGP neighbours.

Notable

• The netnames run GNEO, GTC-NETWORK-1, 111-GNEO-10, 111S-GNEO-4 and 111-GNEO-12: the same four-letter code wrapped in three different numbering schemes, one of which adds a letter to its leading number.
• Three announced blocks are registered to other organisations, including a college and an information services company, under netnames of their own.
• Five of eighteen sampled addresses answered, in three unrelated forms: the last two octets with a service marker, the full address with a different marker, and a short device code with no address in it at all.
• All three forms sit under the same domain, so one zone carries three conventions.

Interesting

• The leading 111 on three netnames is the kind of number that means something inside one office and nothing anywhere else. Adding a letter to it on one block makes a fourth variant of an identifier that already had three.
• Carrying a college's addresses is how small telephone companies fund a network. The institution keeps its own registration, the carrier announces the route, and the registry alone would tell you they are unrelated.
• Three reverse-name schemes in one zone means anything parsing them needs three rules, and the one with no address in it cannot be checked against the address it answers for.