AS15965 AS15965 CEGECOM S.A.

Six reverse names pad every octet to three digits; the seventh is the same idea in capitals with dots.

What it's used for

• A carrier's network. Eight IPv4 prefixes and one IPv6 /32 announced from Luxembourg, twenty-two thousand and sixteen addresses, across one hundred and thirty-three observed BGP neighbours.

Notable

• Seven of eighteen queried addresses answered. Six begin with two letters and a hyphen, then the four octets in reverse order, each padded with leading zeros to three digits.
• The seventh uses the same two letters but separates with dots, keeps the octets in their normal order, drops the padding, and writes the entire name including the domain in capitals.
• Five netnames follow a country code, the brand and a date, with the two oldest falling in the middle and late nineteen-nineties.
• One block belongs to a different company under a netname joining a technology contraction and the country code; another is named with a run-together phrase about connectivity for a secondary operator.
• One block's registry lookup failed, so its details are unknown rather than absent.

Interesting

• Zero-padding makes reverse names sort correctly as text, which matters when the names end up in log files that get sorted rather than parsed. It also makes them fixed width, so a column of them lines up.
• The capitalised outlier is what happens when one zone is maintained by hand alongside six that are generated. DNS ignores case, so nothing breaks and nobody notices for years.