class

IPAddress::IPv6

Inherits Comparable < Enumerable < IPAddress < Reference < Object

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 octets. 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 simplifications 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.

Constants

IN6FORMAT = ("%04x:" * 8).rchop

Format string to pretty print IPv6 addresses.

REGEXP = /^\s*((([0-9A-Fa-f]{1,4}:){7}([0-9A-Fa-f]{1,4}|:))|(([0-9A-Fa-f]{1,4}:){6}(:[0-9A-Fa-f]{1,4}|((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){5}(((:[0-9A-Fa-f]{1,4}){1,2})|:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3})|:))|(([0-9A-Fa-f]{1,4}:){4}(((:[0-9A-Fa-f]{1,4}){1,3})|((:[0-9A-Fa-f]{1,4})?:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){3}(((:[0-9A-Fa-f]{1,4}){1,4})|((:[0-9A-Fa-f]{1,4}){0,2}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){2}(((:[0-9A-Fa-f]{1,4}){1,5})|((:[0-9A-Fa-f]{1,4}){0,3}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(([0-9A-Fa-f]{1,4}:){1}(((:[0-9A-Fa-f]{1,4}){1,6})|((:[0-9A-Fa-f]{1,4}){0,4}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:))|(:(((:[0-9A-Fa-f]{1,4}){1,7})|((:[0-9A-Fa-f]{1,4}){0,5}:((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)(\.(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}))|:)))(%.+)?\s*$/

Inspired by https://gist.github.com/cpetschnig/294476

Constructors

new(addr : String, netmask = nil)

Creates a new IPv6 address object.

An IPv6 address can be expressed in any of the following forms:

  • 2001:0db8:0000:0000:0008:0800:200C:417A: IPv6 address with no compression
  • 2001:db8:0:0:8:800:200C:417A: IPv6 address with leading zeros compression
  • 2001:db8::8:800:200C:417A: IPv6 address with full compression

In all these 3 cases, a new IPv6 address object will be created, using the default subnet mask /128

You can also specify the subnet mask as with IPv4 addresses:

# These two are the same:
ip6 = IPAddress::IPv6.new "2001:db8::8:800:200c:417a/64"
ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
Source
parse_data(data : Bytes, prefix = 128) : IPv6

Creates a new IPv6 object from binary data, like the one you get from a network stream.

For example, on a network stream the IP

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

is represented with the binary data

Bytes[32, 1, 13, 184, 0, 0, 0, 0, 0, 8, 8, 0, 32, 12, 65, 122]

With that data you can create a new IPv6 object:

ip6 = IPAddress::IPv6.parse_data Bytes[32, 1, 13, 184, 0, 0, 0, 0, 0, 8, 8, 0, 32, 12, 65, 122]
ip6.prefix = 64

ip6.to_s # => "2001:db8::8:800:200c:417a/64"
Source
parse_hex(hex : String, prefix = 128) : IPv6

Creates a new IPv6 object from a number expressed in hexadecimal format.

ip6 = IPAddress::IPv6.parse_hex "20010db80000000000080800200c417a"
ip6.prefix = 64

ip6.to_string # => "2001:db8::8:800:200c:417a/64"

The prefix parameter is optional:

ip6 = IPAddress::IPv6.parse_hex "20010db80000000000080800200c417a", 64
ip6.to_string # => "2001:db8::8:800:200c:417a/64"
Source
parse_u128(u128 : BigInt, prefix = 128) : IPv6

Creates a new IPv6 object from an unsigned 128 bits integer.

ip6 = IPAddress::IPv6.parse_u128 "42540766411282592856906245548098208122".to_big_i
ip6.prefix = 64

ip6.to_string # => "2001:db8::8:800:200c:417a/64"

The prefix parameter is optional:

ip6 = IPAddress::IPv6.parse_u128 "42540766411282592856906245548098208122".to_big_i, 64
ip6.to_string # => "2001:db8::8:800:200c:417a/64"
Source

Class methods

compress(addr : String) : String

Compress an IPv6 address in its compressed form.

IPAddress::IPv6.compress "2001:0DB8:0000:CD30:0000:0000:0000:0000"
# => "2001:db8:0:cd30::"
Source
expand(addr : String) : String

Expands an IPv6 address in the canocical form.

IPAddress::IPv6.expand "2001:0DB8:0:CD30::"
# => "2001:0DB8:0000:CD30:0000:0000:0000:0000"
Source
groups(addr : String) : Array(Int32)

Extract 16 bit groups from a string.

Source
valid?(addr : String)

Returns true if the given string is a valid IPv6 address.

IPAddress::IPv6.valid? "2002::1"          # => true
IPAddress::IPv6.valid? "2002::DEAD::BEEF" # => false
Source

Instance methods

<=>(other : IPv6)

Spaceship operator to compare IPv6 objects.

Comparing IPv6 addresses is useful to ordinate them into lists that match our intuitive perception of ordered IP addresses.

The first comparison criteria is the u128 value. For example, 2001:db8:1::1 will be considered to be less than 2001:db8:2::1, because, in a ordered list, we expect 2001:db8:1::1 to come before 2001:db8:2::1.

The second criteria, in case two IPv6 objects have identical addresses, is the prefix. An higher prefix will be considered greater than a lower prefix. This is because we expect to see 2001:db8:1::1/64 come before 2001:db8:1::1/65.

ip1 = IPAddress.new "2001:db8:1::1/64"
ip2 = IPAddress.new "2001:db8:2::1/64"
ip3 = IPAddress.new "2001:db8:1::1/65"

ip1 < ip2 # => true
ip1 < ip3 # => false

[ip1, ip2, ip3].sort.map &.to_string
# => ["2001:db8:1::1/64", "2001:db8:1::1/65", "2001:db8:2::1/64"]
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==(other : self)

Returns true if this reference is the same as other. Invokes same?.

[](index : Int32) : Int32

Returns the 16-bits value specified by index.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"

ip6[0] # => 8193
ip6[1] # => 3512
ip6[2] # => 0
ip6[3] # => 0

See also: #groups

Source
[]=(index : Int32, value : Int32) : Nil

Updates the 16-bits value specified at index.

See also: #groups

Source
address

Returns the IPv6 address in uncompressed form.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.address # => "2001:0db8:0000:0000:0008:0800:200c:417a"
Source
bits

Returns the address portion of an IP in binary format, as a string containing a sequence of 0 and 1.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a"
ip6.bits # => "0010000000000001000011011011100000 [...]"
Source
broadcast_u128

Returns the broadcast address in unsigned 128 bits format.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.broadcast_u128 # => 42540766411282592875350729025363378175

NOTE: Please note that there is no broadcast concept in IPv6 addresses as in IPv4 addresses, and this method is just a helper to other functions.

Source
compressed

Compressed form of the IPv6 address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.compressed # => "2001:db8::8:800:200c:417a"
Source
data

Returns the address portion of an IPv6 object in a network byte order format (IO::ByteFormat::NetworkEndian).

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.data # => Bytes[172, 16, 10, 1]

It is usually used to include an IP address in a data packet to be sent over a socket

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
socket = Socket.new(params) # socket details here

# Send binary data
socket.send "Address: "
socket.send ip6.data
Source
each

Iterates over all the IP addresses for the given network (or IP address).

The object yielded is a new IPv6 object created from the iteration.

ip6 = IPAddress.new "2001:db8::4/125"

ip6.each do |i|
  p i.compressed
end
# => "2001:db8::"
# => "2001:db8::1"
# => "2001:db8::2"
# => "2001:db8::3"
# => "2001:db8::4"
# => "2001:db8::5"
# => "2001:db8::6"
# => "2001:db8::7"

NOTE: If the host portion is very large, this method can be very slow and possibly hang your system!

Source
groups

Returns an array with the 16 bit groups in decimal format.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.groups # => [8193, 3512, 0, 0, 8, 2048, 8204, 16762]
Source
hash(hasher)

See Object#hash(hasher)

hexs

Returns an array of the 16 bits groups in hexadecimal format.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.hexs # => ["2001", "0db8", "0000", "0000", "0008", "0800", "200c", "417a"]

Not to be confused with the similar #to_hex method.

Source
includes?(others : Array(IPv6))

ditto

Source
includes?(other)

Checks whether a subnet includes the given IP address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"

addr1 = IPAddress.new "2001:db8::8:800:200c:1/128"
addr2 = IPAddress.new "2001:db8:1::8:800:200c:417a/76"

ip6.includes? addr1 # => true
ip6.includes? addr2 # => false
Source
includes?(*others : IPv6)

Checks whether a subnet includes all the given IPv6 objects.

ip6 = IPAddress.new "2001:db8::4/125"

addr1 = IPAddress.new "2001:db8::2/125"
addr2 = IPAddress.new "2001:db8::7/125"

ip6.includes? addr1, addr2 # => true
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link_local?

Checks if an IPv6 address objects belongs to a link-local network RFC4291.

ip = IPAddress.new "fe80::1"
ip.link_local? # => true
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literal

Literal version of the IPv6 address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.literal # => "2001-0db8-0000-0000-0008-0800-200c-417a.ipv6-literal.net"
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loopback?

Returns true if the address is a loopback address.

See IPv6::Loopback for more information.

Source
mapped?

Returns true if the address is a mapped address.

See IPv6::Mapped for more information.

Source
network

Returns a new IPv6 object with the network number for the given IP.

ip6 = IPAddress.new "2001:db8:1:1:1:1:1:1/32"
ip6.network.to_string # => "2001:db8::/32"
Source
network?

Returns true if the IPv6 address is a network.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.network? # => false

ip6 = IPAddress.new "2001:db8:8:800::/64"
ip6.network? # => true
Source
network_u128

Returns the network number in unsigned 128 bits format.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.network_u128 # => 42540766411282592856903984951653826560
Source
pred

Returns the predecessor to the IP address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.pred.to_string # => "2001:db8::8:800:200c:4179/64"
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prefix

Returns an instance of the prefix object.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.prefix # => 64
Source
prefix=(prefix : Int32) : Prefix128

Set a new prefix number for the object.

This is useful if you want to change the prefix to an object created with IPv6.parse_u128 or if the object was created using the default prefix of 128 bits.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a"
ip6.to_string # => "2001:db8::8:800:200c:417a/128"

ip6.prefix = 64
ip6.to_string # => "2001:db8::8:800:200c:417a/64"
Source
reverse

Returns the IPv6 address in a DNS reverse lookup string, as per RFC3172 and RFC2874.

ip6 = IPAddress.new "3ffe:505:2::f"
ip6.reverse # => "f.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.0.2.0.0.0.5.0.5.0.e.f.f.3.ip6.arpa"
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size

Returns the number of IP addresses included in the network. It also counts the network address and the broadcast address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.size # => 18446744073709551616
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succ

Returns the successor to the IP address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.succ.to_string # => "2001:db8::8:800:200c:417b/64"
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to_big_i

Returns a decimal format (unsigned 128 bit) of the IPv6 address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.to_big_i # => 42540766411282592856906245548098208122
Source
to_hex

Returns a base16 number representing the IPv6 address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.to_hex # => "20010db80000000000080800200c417a"
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to_s(io : IO)

Appends to the given IO the IPv6 address in a human readable form, using the compressed address.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.to_s # => "2001:db8::8:800:200c:417a"
Source
to_string

Returns the IPv6 address in a human readable form, using the compressed address.

ip6 = IPAddress.new "2001:0db8:0000:0000:0008:0800:200c:417a/64"
ip6.to_string # => "2001:db8::8:800:200c:417a/64"
Source
to_string_uncompressed

Unlike its counterpart #to_string method, #to_string_uncompressed returns the whole IPv6 address and prefix in an uncompressed form.

ip6 = IPAddress.new "2001:db8::8:800:200c:417a/64"
ip6.to_string_uncompressed # => "2001:0db8:0000:0000:0008:0800:200c:417a/64"
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unique_local?

Checks if an IPv6 address objects belongs to a unique-local network RFC4193.

ip = IPAddress.new "fc00::1"
ip.unique_local? # => true
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unspecified?

Returns true if the address is an unspecified address.

See IPv6::Unspecified for more information.

Source

Nested types