BoundaryException¶

exception privex.helpers.exceptions.BoundaryException[source]¶

Thrown when the v4/v6 address boundary for a reverse DNS record is invalid.

An “address boundary” is the minimum amount of bits that defines a character in a reverse DNS domain (i.e. those ending in in-addr/ip6.arpa):

IPv6 uses “nibbles” of 4 bits for each individual character in a standard 128-bit address

IPv4 uses “octets” of 8 bits, which represent 0-255 in each of the 4 “blocks” within an IPv4 address

This means the minimum and maximum boundaries for IPv4 and IPv6 are as such:

IPv6 - Minimum boundary: 4 bits (*.f.ip6.arpa), Maximum boundary: 128 bits (rDNS for a single address, i.e. a /128) IPv4 - Minimum boundary: 8 bits (x.x.x.127.in-addr.arpa), Maximum boundary: 32 bits (1.0.0.127.in-addr.arpa)