Weird private ip

Hi @MahMush

I'm sorry for my delay.

Thanks for your question:

According to IANA - RFC 6761 - Address Allocation for Private Internets

These are the Private Address Space

The Internet Assigned Numbers Authority (IANA) has reserved the following three blocks of the IP address space for private internets:

10.0.0.0 - 10.255.255.255 (10/8 prefix)
172.16.0.0 - 172.31.255.255 (172.16/12 prefix)
192.168.0.0 - 192.168.255.255 (192.168/16 prefix)

Reference: https://datatracker.ietf.org/doc/html/rfc1918


CIDR format, or "Classless Inter-Domain Routing", released in 1993, is the industry standard for displaying IP addresses and their related subnets. It consists of a network prefix and the significant bits which determines the size of the IP block. Significant bits are in 8-bit groups that form Class A, B, and C blocks of IP addresses.

Here you can see all CIDR blocks:(IANA IPv4 Special-Purpose Address Registry)

IANA IPv4 Special-Purpose Address Registry = [RFC5736][RFC6890][RFC Errata 6404][RFC8190]

https://www.iana.org/assignments/iana-ipv4-special-registry/iana-ipv4-special-registry.xhtml


There are a IANA-Reserved IPv4 Prefix for Shared Address Space that use this range: 100.64.0.0/1 Shared Address Space

It requests the allocation of an IPv4 /10 address block to be used as Shared Address Space to accommodate the needs of Carrier- Grade NAT (CGN) devices. It is anticipated that Service Providers will use this Shared Address Space to number the interfaces that connect CGN devices to Customer Premises Equipment (CPE).

Shared Address Space is distinct from RFC 1918 private address space because it is intended for use on Service Provider networks.
However, it may be used in a manner similar to RFC 1918 private address space on routing equipment that is able to do address translation across router interfaces when the addresses are identical on two different interfaces.

I imagine that could be your case;

Thanks for your questions and I hope that help you;