Private, reserved, or special-purpose?

Matches the IANA "Shared address space (CGN)" block 100.64.0.0/10 (RFC 6598). The registry marks this block not globally reachable.

Class A (classful-era label — routing has been classless since CIDR, RFC 4632)

IANA IPv4 and IPv6 Special-Purpose Address Registries (iana.org/assignments), hand-distilled snapshot, snapshot 2026-08-24

IPv4 registry rows

• 0.0.0.0/8This network
• 10.0.0.0/8Private use
• 100.64.0.0/10Shared address space (CGN)
• 127.0.0.0/8Loopback
• 169.254.0.0/16Link-local
• 172.16.0.0/12Private use
• 192.0.0.0/24IETF protocol assignments
• 192.0.2.0/24Documentation (TEST-NET-1)
• 192.88.99.0/24Deprecated (6to4 relay anycast)
• 192.168.0.0/16Private use
• 198.18.0.0/15Benchmarking
• 198.51.100.0/24Documentation (TEST-NET-2)
• 203.0.113.0/24Documentation (TEST-NET-3)
• 240.0.0.0/4Reserved (former class E)
• 255.255.255.255/32Limited broadcast

IPv6 registry rows

• ::/128Unspecified
• ::1/128Loopback
• ::ffff:0:0/96IPv4-mapped
• 64:ff9b::/96IPv4/IPv6 translation (NAT64)
• 100::/64Discard-only
• 2001::/23IETF protocol assignments (includes 2001:db8::/32 documentation)
• 2001:2::/48Benchmarking
• 2001:10::/28Deprecated (ORCHID)
• 2001:20::/28ORCHIDv2
• 2001:db8::/32Documentation
• 2002::/166to4
• fc00::/7Unique-local (ULA)
• fe80::/10Link-local
• ff00::/8Multicast

• Not a routing decision: "not in the snapshot" means commonly treated as public — your own network's routes and filters are the truth there.
• Not a geolocation or reputation lookup — nothing about this address leaves the tab.
• The legacy class A–E label is history (classless since CIDR, RFC 4632); it is included because old docs still use it.