Class | IPAddress::IPv6::Mapped |
In: |
lib/ipaddress/ipv6.rb
|
Parent: | IPAddress::IPv6 |
It is usually identified as a IPv4 mapped IPv6 address, a particular IPv6 address which aids the transition from IPv4 to IPv6. The structure of the address is
::ffff:w.y.x.z
where w.x.y.z is a normal IPv4 address. For example, the following is a mapped IPv6 address:
::ffff:192.168.100.1
IPAddress is very powerful in handling mapped IPv6 addresses, as the IPv4 portion is stored internally as a normal IPv4 object. Let‘s have a look at some examples. To create a new mapped address, just use the class builder itself
ip6 = IPAddress::IPv6::Mapped.new "::ffff:172.16.10.1/128"
or just use the wrapper method
ip6 = IPAddress "::ffff:172.16.10.1/128"
Let‘s check it‘s really a mapped address:
ip6.mapped? #=> true ip6.to_s #=> "::FFFF:172.16.10.1/128"
Now with the +ipv4+ attribute, we can easily access the IPv4 portion of the mapped IPv6 address:
ip6.ipv4.address #=> "172.16.10.1"
Internally, the IPv4 address is stored as two 16 bits groups. Therefore all the usual methods for an IPv6 address are working perfectly fine:
ip6.to_hex #=> "00000000000000000000ffffac100a01" ip6.address #=> "0000:0000:0000:0000:0000:ffff:ac10:0a01"
A mapped IPv6 can also be created just by specify the address in the following format:
ip6 = IPAddress "::172.16.10.1"
That is, two colons and the IPv4 address. However, as by RFC, the ffff group will be automatically added at the beginning
ip6.to_s => "::ffff:172.16.10.1/128"
making it a mapped IPv6 compatible address.
ipv4 | [R] | Access the internal IPv4 address |
Creates a new IPv6 IPv4-mapped address
ip6 = IPAddress::IPv6::Mapped.new "::ffff:172.16.10.1/128" ipv6.ipv4.class #=> IPAddress::IPv4
An IPv6 IPv4-mapped address can also be created using the IPv6 only format of the address:
ip6 = IPAddress::IPv6::Mapped.new "::0d01:4403" ip6.to_s #=> "::ffff:13.1.68.3"
Similar to IPv6#to_string, but prints out the IPv4 address in dotted decimal format
ip6 = IPAddress "::ffff:172.16.10.1/128" ip6.to_string #=> "::ffff:172.16.10.1/128"