AS15457 — NOS_MADEIRA

AS15457 announces 8 IPv4 prefixes covering 69,632 addresses and 1 IPv6 prefixes.

About this network

The reverse zone is split by the first octet, and the subdomain says which one.

What it's used for

• An island cable television and internet operator. Eight IPv4 prefixes and one IPv6 /29 announced from Portugal, sixty-nine thousand addresses, through one observed BGP neighbour.

Notable

• Every one of the fifteen answering addresses takes the same form: the four octets in dashes, then a subdomain made of the letters for pointer record and the address's own first octet, then the company domain.
• Seven of the eight blocks are the same size, and each netname carries the country code, a former cable television brand, and its allocation date.
• Those dates run across more than a decade, one block roughly every eighteen months.
• The abuse contact is written as a lower case string with a dot in it, shaped like a domain rather than a name.
• Eighteen addresses were queried for reverse DNS and fifteen returned a name.

Interesting

• Partitioning the reverse zone by first octet is a practical answer to holding blocks from eight unrelated ranges. Each range gets its own subtree and they never collide.
• Cable operators became internet providers by laying the same coaxial they already had, and the old brand surviving in every netname is the record of that.
• Sixty-nine thousand addresses behind one observed neighbour is the exposure worth naming. An island network with one path is one cable away from being cut off.

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

Announced prefixes

• 83.223.160.0/19
• 84.23.192.0/19
• 89.109.64.0/18
• 95.172.160.0/19
• 159.255.48.0/20
• 188.125.192.0/19
• 213.138.224.0/19
• 213.190.192.0/19
• 2a00:d180::/29

Upstream networks

• AS2860 NOS COMUNICACOES, S.A.

Adjacent networks

• AS2860 NOS COMUNICACOES, S.A.