class IPAddress::IPv6

• IPAddress::IPv6
• Reference
• Object

Overview

Class IPAddress::IPv6 is used to handle IPv6 type addresses.

IPv6 addresses

IPv6 addresses are 128 bits long, in contrast with IPv4 addresses which are only 32 bits long. An IPv6 address is generally written as eight groups of four hexadecimal digits, each group representing 16 bits or two octect. For example, the following is a valid IPv6 address:

2001:0db8:0000:0000:0008:0800:200c:417a

Letters in an IPv6 address are usually written downcase, as per RFC. You can create a new IPv6 object using uppercase letters, but they will be converted.

Compression

Since IPv6 addresses are very long to write, there are some semplifications and compressions that you can use to shorten them.

• Leading zeroes: all the leading zeroes within a group can be omitted: "0008" would become "8"

• A string of consecutive zeroes can be replaced by the string "::". This can be only applied once.

Using compression, the IPv6 address written above can be shorten into the following, equivalent, address:

2001:db8::8:800:200c:417a

This short version is often used in human representation.

Network Mask

As we used to do with IPv4 addresses, an IPv6 address can be written using the prefix notation to specify the subnet mask:

2001:db8::8:800:200c:417a/64

The /64 part means that the first 64 bits of the address are representing the network portion, and the last 64 bits are the host portion.

Included Modules

• Comparable(IPAddress::IPv6)
• Enumerable(IPAddress::IPv6)
• IPAddress

Defined in:

lib/ipaddress/src/ipaddress/ipv6.cr
network.cr

Instance Method Summary

• #includes?(other : IPv4)
• #includes?(others : Array(IPv4))
• #includes?(*others : IPv4)

Instance Method Detail