AS13916 — PROOFPOINT-UT7

AS13916 announces 4 IPv4 prefixes covering 1,280 addresses and 2 IPv6 prefixes.

About this network

Two addresses answered, and between them they named two brands that are not the one on the AS.

What it's used for

• An email security company's network. 1,280 addresses across four IPv4 prefixes, two IPv6 prefixes, and three observed BGP neighbours.

Notable

• Two blocks are netname PROOFPOINT-NET-NORTH-AMERICA and two are CLOUDMARK-IPV4-1, all registered to Proofpoint, Inc.
• The reverse names that answered are discovery.cd.cloudmark.com and mx2.mailadded.com.
• The IPv6 prefixes are 2620:0:2901::/48 and 2620:100:9008::/47.

Interesting

• A netname naming one company and a registrant naming another, with the reverse zone still serving the first, is an acquisition that finished on paper and not in DNS. The registry record was updated because someone has to hold the block; the hostnames were left because changing them would break whatever refers to them.
• The third domain belongs to neither and answers on the same block, which is the ordinary state of a mail platform: the brand a customer bought is rarely the brand the machine answers as.
• A /47 is an unusual length to announce. It is two adjacent /48s advertised as one, which keeps the routing table shorter than the allocation would suggest.

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

Announced prefixes

• 148.163.128.0/23
• 148.163.130.0/24
• 208.83.136.0/24
• 208.83.138.0/24
• 2620:0:2901::/48
• 2620:100:9008::/47

Upstream networks

• AS1299 Arelion Sweden AB
• AS3356 Level 3 Parent, LLC
• AS174 Cogent Communications, LLC

Adjacent networks

• AS1299 Arelion Sweden AB
• AS3356 Level 3 Parent, LLC
• AS174 Cogent Communications, LLC

Routing security

• RPKI: 4 valid, 0 invalid and 4 not-found announcements; 10 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 22 route objects.
• Listed in as-sets: AS-DATABANK, AS-INCAPSULA, AS-INCAPSULA, AS-PNAPBSN, AS-PROOFPOINT, AS1299:AS-TWELVE99-NA-V4, AS1299:AS-TWELVE99-NA-V6, AS19551:AS-IMPERVA.