AS15250 USFAMILY-ASN

The one block named for the brand answers under a different domain than the other five.

What it's used for

• A regional internet provider. Six IPv4 prefixes announced from the United States, no IPv6, and fifteen thousand addresses across four observed neighbours.

Notable

• Five blocks share a netname that is a six-letter string matching nothing else in the record, while the sixth carries an abbreviation of the brand in the AS handle with a counter.
• The reverse names invert that grouping: the five oddly named blocks answer under the brand's domain, and the block named for the brand answers under a completely different one.
• All eighteen sampled addresses answered, every one writing the address into the host label with hyphens.
• The AS handle names a consumer brand while the registrant names the company that now owns it.
• Three names in the record, three different organisations implied, one operator.

Interesting

• The inversion is the interesting part. Whichever way the blocks were grouped in the registry, the reverse zones were grouped the other way, so neither view predicts the other. A tool that guesses the service from the netname gets this network exactly backwards.
• A full sample of eighteen answers with no gaps means the reverse zones cover the space completely, generated rather than curated, so a name here proves delegation and not use.
• Two consumer domains on one provider is usually a merger where both brands kept their subscribers, and the registry records only the survivor.