Creating a rule for Autonomous System Number (ASN)

[ThOhT]

It would be great if someone create a validation rule for ASN (Autonomous System Number) based on the RFC.

"There are two different formats to represent ASNs: 2-byte and 4-byte.

A 2-byte ASN is a 16-bit number. This format provides for 65,536 ASNs (0 to 65535). From these ASNs, the Internet Assigned Numbers Authority (IANA) reserved 1,023 of them (64512 to 65534) for private use.

A 4-byte ASN is a 32-bit number. This format provides for 232 or 4,294,967,296 ASNs (0 to 4294967295). IANA reserved a block of 94,967,295 ASNs (4200000000 to 4294967294) for private use.

Up until the Internet Engineering Task Force (IETF) proposed a gradual transition to 4-byte ASNs in 2007, all ASNs were 2-byte. There is no longer a distinction between a 2-byte and 4-byte ASN, and all ASNs should be considered 4-byte."

Read more here: https://www.arin.net/resources/guide/asn/

Some examples could be:
v::asn()->validate('4230'); // true v::asn()->validate('AS4230'); // true (case insensitive) v::asn()->validate('ASN4230'); // false (not valid to use "ASN", just AS or just the number) v::asn('AS4230')->private(); // false v::asn('4294967294')->private(); // true v::asn('65534')->private(); //true