Reserved / Special-use CIDR

100.72.64.0/19

8.2K IPs /19 Reserved · RFC 6598 IANA

⚠

Carrier-grade NAT (CGN) · RFC 6598

Shared address space used by ISPs for carrier-grade NAT. Not routable on the public internet; allows providers to run large NAT pools without colliding with private RFC 1918 space.

This range is reserved by IANA — it is not allocated to an organization, ISP, or regional internet registry. Addresses here appear on every private/internal network that follows the standard, so lookups will not identify a specific owner. 100.72.64.0/19 is a sub-block of 100.64.0.0/10, the defining reserved range.

Addresses

8,192

8.2K

IP Range

100.72.64.0

→ 100.72.95.255

Sub-ranges

within this block

First and last addresses in 100.72.64.0/19

100.72.64.0/19 runs from 100.72.64.0 to 100.72.95.255.

First 16

100.72.64.0 100.72.64.1 100.72.64.2 100.72.64.3 100.72.64.4 100.72.64.5 100.72.64.6 100.72.64.7 100.72.64.8 100.72.64.9 100.72.64.10 100.72.64.11 100.72.64.12 100.72.64.13 100.72.64.14 100.72.64.15

Last 16

100.72.95.240 100.72.95.241 100.72.95.242 100.72.95.243 100.72.95.244 100.72.95.245 100.72.95.246 100.72.95.247 100.72.95.248 100.72.95.249 100.72.95.250 100.72.95.251 100.72.95.252 100.72.95.253 100.72.95.254 100.72.95.255

BGP Routing

Live BGP anomalies →

This block is announced in BGP, observed across our RIPE RIS collectors.

Announced prefix

100.72.64.0/19

Origin AS

AS8764

Announcement samples

Last seen

2026-09-08 00:34:07

Frequently Asked Questions

What is 100.72.64.0/19?

100.72.64.0/19 falls inside 100.64.0.0/10 — a Carrier-grade NAT (CGN) range reserved by RFC 6598. Shared address space used by ISPs for carrier-grade NAT. Not routable on the public internet; allows providers to run large NAT pools without colliding with private RFC 1918 space.

Is 100.72.64.0/19 routable on the public internet?

No. 100.72.64.0/19 is part of IANA-reserved special-use space (100.64.0.0/10, RFC 6598). Packets with these addresses are either filtered by backbone routers or handled as local/special traffic — they never reach the public internet.

Who owns 100.72.64.0/19?

100.72.64.0/19 is not allocated to any organization or ISP. It is part of the Carrier-grade NAT (CGN) block reserved by IANA under RFC 6598 for every network to use privately.

Last updated: 2026-11-03 18:24:07 UTC