AS12887 — NETIA-AS2

AS12887 announces 39 IPv4 prefixes covering 19,712 addresses and 0 IPv6 prefixes.

About this network

An autonomous system created in 2025 to hold one thing: carrier-grade NAT address space.

What it's used for

• A Polish operator's second autonomous system, carrying the addresses its subscribers are translated behind. 19,712 addresses across 39 IPv4 prefixes, two observed BGP neighbours, and no IPv6 announced.

Notable

• Most blocks are /22s, and most carry the netname NETIA-CGNAT.
• 84.40.156.0/22 is the older PL-NETIA-20040903.
• All eighteen sampled addresses returned names, every one of the form 84-40-157-0.cgnat.inetia.pl.
• First observed in the routing archive in February 2025.

Interesting

• Almost every AS in this range first appears in the routing archive around 2000. This one appears in 2025, which makes it a useful contrast: new autonomous systems are rarely new companies now, they are existing operators splitting a function out into its own number.
• The function here is carrier-grade NAT, where thousands of subscribers share one public address. Naming the netname, the AS and the entire reverse zone cgnat is unusually honest — operators often hide the arrangement, and stating it plainly helps anyone diagnosing why one address seems to be in several places at once.
• Eighteen of eighteen addresses answering, all from one template, is what a purpose-built network looks like. Nothing here accumulated over decades; the whole thing was generated at once for a single job.
• An AS that exists because IPv4 ran out, announcing no IPv6 at all. Carrier NAT is the alternative to deploying the protocol that would remove the need for it, and this record is that trade-off written down.

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

Announced prefixes

• 84.40.152.0/23
• 84.40.155.0/24
• 84.40.156.0/22
• 84.40.216.0/24
• 84.40.218.0/23
• 84.40.220.0/22
• 84.40.232.0/22
• 84.40.237.0/24
• 84.40.238.0/23
• 93.159.0.0/22
• 93.159.4.0/23
• 93.159.7.0/24
• 93.159.12.0/23
• 93.159.14.0/24
• 93.159.16.0/23
• 93.159.18.0/24
• 93.159.20.0/24
• 93.159.22.0/24
• 93.159.24.0/22
• 93.159.28.0/24
• 93.159.33.0/24
• 93.159.34.0/23
• 93.159.36.0/24
• 93.159.40.0/24
• 93.159.42.0/24
• 93.159.45.0/24
• 93.159.46.0/23
• 93.159.48.0/23
• 93.159.55.0/24
• 93.159.57.0/24
• 93.159.58.0/23
• 93.159.60.0/22
• 185.72.184.0/22
• 185.164.140.0/22
• 194.9.78.0/23
• 195.85.209.0/24
• 195.128.172.0/23
• 195.128.180.0/23
• 195.160.174.0/23

Upstream networks

• AS12741 Netia SA

Downstream networks

• AS29167 Netia SA

Adjacent networks

• AS12741 Netia SA
• AS29167 Netia SA

Routing security

• RPKI: 42 valid, 0 invalid and 0 not-found announcements; 42 ROAs.
• ASPA: none published.
• IRR: 100% of announcements registered; 44 route objects.
• Listed in as-sets: AS-NETIA, AS-NETIA-MSK-IX, AS5617:AS-PL, AS5617:AS-PL-TRANSIT.