class IPAddress::IPv4

Name

IPAddress::IPv4 - IP version 4 address manipulation library

Synopsis

require 'ipaddress'

Description

Class IPAddress::IPv4 is used to handle IPv4 type addresses.

Constants

CLASSFUL

This Hash contains the prefix values for Classful networks

Note that classes C, D and E will all have a default prefix of /24 or 255.255.255.0

REGEXP

Regular expression to match an IPv4 address

Public Class Methods

extract(str) click to toggle source

Extract an IPv4 address from a string and returns a new object

Example:

str = "foobar172.16.10.1barbaz"
ip = IPAddress::IPv4::extract str

ip.to_s
  #=> "172.16.10.1"
# File lib/ipaddress/ipv4.rb, line 846
def self.extract(str)
  self.new REGEXP.match(str).to_s
end
new(str) click to toggle source

Creates a new IPv4 address object.

An IPv4 address can be expressed in any of the following forms:

  • "10.1.1.1/24": ip address and prefix. This is the common and

suggested way to create an object .

  • "10.1.1.1/255.255.255.0": ip address and netmask. Although

convenient sometimes, this format is less clear than the previous one.

  • "10.1.1.1": if the address alone is specified, the prefix will be

set as default 32, also known as the host prefix

Examples:

# These two are the same
ip = IPAddress::IPv4.new("10.0.0.1/24")
ip = IPAddress("10.0.0.1/24")

# These two are the same
IPAddress::IPv4.new "10.0.0.1/8"
IPAddress::IPv4.new "10.0.0.1/255.0.0.0"
# File lib/ipaddress/ipv4.rb, line 63
def initialize(str)
  ip, netmask = str.split("/")
  
  # Check the ip and remove white space
  if IPAddress.valid_ipv4?(ip)
    @address = ip.strip
  else
    raise ArgumentError, "Invalid IP #{ip.inspect}"
  end
  
  # Check the netmask
  if netmask  # netmask is defined
    netmask.strip!
    if netmask =~ %r^\d{1,2}$/  # netmask in cidr format 
      @prefix = Prefix32.new(netmask.to_i)
    elsif IPAddress.valid_ipv4_netmask?(netmask)  # netmask in IP format
      @prefix = Prefix32.parse_netmask(netmask)
    else  # invalid netmask
      raise ArgumentError, "Invalid netmask #{netmask}"
    end
  else  # netmask is nil, reverting to defaul classful mask
    @prefix = Prefix32.new(32)
  end

  # Array formed with the IP octets
  @octets = @address.split(".").map{|i| i.to_i}
  # 32 bits interger containing the address
  @u32 = (@octets[0]<< 24) + (@octets[1]<< 16) + (@octets[2]<< 8) + (@octets[3])
  
end
parse_classful(ip) click to toggle source

Creates a new IPv4 address object by parsing the address in a classful way.

Classful addresses have a fixed netmask based on the class they belong to:

  • Class A, from 0.0.0.0 to 127.255.255.255

  • Class B, from 128.0.0.0 to 191.255.255.255

  • Class C, D and E, from 192.0.0.0 to 255.255.255.254

Example:

ip = IPAddress::IPv4.parse_classful "10.0.0.1"

ip.netmask 
  #=> "255.0.0.0"
ip.a?
  #=> true

Note that classes C, D and E will all have a default prefix of /24 or 255.255.255.0

# File lib/ipaddress/ipv4.rb, line 957
def self.parse_classful(ip)
  if IPAddress.valid_ipv4?(ip)
    address = ip.strip
  else
    raise ArgumentError, "Invalid IP #{ip.inspect}"
  end
  prefix = CLASSFUL.find{|h,k| h === ("%.8b" % address.to_i)}.last
  self.new "#{address}/#{prefix}"
end
parse_data(str, prefix=32) click to toggle source

Creates a new IPv4 object from binary data, like the one you get from a network stream.

For example, on a network stream the IP 172.16.0.1 is represented with the binary "254020n001".

ip = IPAddress::IPv4::parse_data "\2254\0020\n\0001"
ip.prefix = 24

ip.to_string
  #=> "172.16.10.1/24"
# File lib/ipaddress/ipv4.rb, line 830
def self.parse_data(str, prefix=32)
  self.new(str.unpack("C4").join(".")+"/#{prefix}")
end
parse_u32(u32, prefix=32) click to toggle source

Creates a new IPv4 object from an unsigned 32bits integer.

ip = IPAddress::IPv4::parse_u32(167772160)

ip.prefix = 8
ip.to_string
  #=> "10.0.0.0/8"

The prefix parameter is optional:

ip = IPAddress::IPv4::parse_u32(167772160, 8)

ip.to_string
  #=> "10.0.0.0/8"
# File lib/ipaddress/ipv4.rb, line 813
def self.parse_u32(u32, prefix=32)
  self.new([u32].pack("N").unpack("C4").join(".")+"/#{prefix}")
end
summarize(*args) click to toggle source

Summarization (or aggregation) is the process when two or more networks are taken together to check if a supernet, including all and only these networks, exists. If it exists then this supernet is called the summarized (or aggregated) network.

It is very important to understand that summarization can only occur if there are no holes in the aggregated network, or, in other words, if the given networks fill completely the address space of the supernet. So the two rules are:

1) The aggregate network must contain all the IP addresses of the

original networks;

2) The aggregate network must contain only the IP addresses of the

original networks;

A few examples will help clarify the above. Let's consider for instance the following two networks:

ip1 = IPAddress("172.16.10.0/24")
ip2 = IPAddress("172.16.11.0/24")

These two networks can be expressed using only one IP address network if we change the prefix. Let Ruby do the work:

IPAddress::IPv4::summarize(ip1,ip2).to_s
  #=> "172.16.10.0/23"

We note how the network "172.16.10.0/23" includes all the addresses specified in the above networks, and (more important) includes ONLY those addresses.

If we summarized ip1 and ip2 with the following network:

"172.16.0.0/16"

we would have satisfied rule #1 above, but not rule #2. So "172.16.0.0/16" is not an aggregate network for ip1 and ip2.

If it's not possible to compute a single aggregated network for all the original networks, the method returns an array with all the aggregate networks found. For example, the following four networks can be aggregated in a single /22:

ip1 = IPAddress("10.0.0.1/24")
ip2 = IPAddress("10.0.1.1/24")
ip3 = IPAddress("10.0.2.1/24")
ip4 = IPAddress("10.0.3.1/24")

IPAddress::IPv4::summarize(ip1,ip2,ip3,ip4).to_string
  #=> "10.0.0.0/22",

But the following networks can't be summarized in a single network:

ip1 = IPAddress("10.0.1.1/24")
ip2 = IPAddress("10.0.2.1/24")
ip3 = IPAddress("10.0.3.1/24")
ip4 = IPAddress("10.0.4.1/24")

IPAddress::IPv4::summarize(ip1,ip2,ip3,ip4).map{|i| i.to_string}
  #=> ["10.0.1.0/24","10.0.2.0/23","10.0.4.0/24"]
# File lib/ipaddress/ipv4.rb, line 912
def self.summarize(*args)
  # one network? no need to summarize
  return [args.first.network] if args.size == 1
  
  i = 0
  result = args.dup.sort.map{|ip| ip.network}
  while i < result.size-1
    sum = result[i] + result[i+1]
    result[i..i+1] = sum.first if sum.size == 1
    i += 1
  end
  
  result.flatten!
  if result.size == args.size
    # nothing more to summarize
    return result
  else
    # keep on summarizing
    return self.summarize(*result)
  end
end

Public Instance Methods

+(oth) click to toggle source

Returns a new IPv4 object which is the result of the summarization, if possible, of the two objects

Example:

ip1 = IPAddress("172.16.10.1/24")
ip2 = IPAddress("172.16.11.2/24")

p (ip1 + ip2).map {|i| i.to_string}
  #=> ["172.16.10.0/23"]

If the networks are not contiguous, returns the two network numbers from the objects

ip1 = IPAddress("10.0.0.1/24")
ip2 = IPAddress("10.0.2.1/24")

p (ip1 + ip2).map {|i| i.to_string}
  #=> ["10.0.0.0/24","10.0.2.0/24"]
# File lib/ipaddress/ipv4.rb, line 729
def +(oth)
  aggregate(*[self,oth].sort.map{|i| i.network})
end
-(oth) click to toggle source

Returns the difference between two IP addresses in unsigned int 32 bits format

Example:

ip1 = IPAddress("172.16.10.0/24")
ip2 = IPAddress("172.16.11.0/24")

puts ip1 - ip2
  #=> 256
# File lib/ipaddress/ipv4.rb, line 703
def -(oth)
  return (to_u32 - oth.to_u32).abs
end
/(subnets=2) click to toggle source
Alias for: split
<=>(oth) click to toggle source

Spaceship operator to compare IPv4 objects

Comparing IPv4 addresses is useful to ordinate them into lists that match our intuitive perception of ordered IP addresses.

The first comparison criteria is the u32 value. For example, 10.100.100.1 will be considered to be less than 172.16.0.1, because, in a ordered list, we expect 10.100.100.1 to come before 172.16.0.1.

The second criteria, in case two IPv4 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 10.100.100.0/24 come before 10.100.100.0/25.

Example:

ip1 = IPAddress "10.100.100.1/8"
ip2 = IPAddress "172.16.0.1/16"
ip3 = IPAddress "10.100.100.1/16"

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

[ip1,ip2,ip3].sort.map{|i| i.to_string}
  #=> ["10.100.100.1/8","10.100.100.1/16","172.16.0.1/16"]
# File lib/ipaddress/ipv4.rb, line 460
def <=>(oth)
  return prefix <=> oth.prefix if to_u32 == oth.to_u32  
  to_u32 <=> oth.to_u32
end
[](index) click to toggle source

Returns the octet specified by index

ip = IPAddress("172.16.100.50/24")

ip[0]
  #=> 172
ip[1]
  #=> 16
ip[2]
  #=> 100
ip[3]
  #=> 50
# File lib/ipaddress/ipv4.rb, line 270
def [](index)
  @octets[index]
end
Also aliased as: octet
a?() click to toggle source

Checks whether the ip address belongs to a RFC 791 CLASS A network, no matter what the subnet mask is.

Example:

ip = IPAddress("10.0.0.1/24")

ip.a?
  #=> true
# File lib/ipaddress/ipv4.rb, line 745
def a?
  CLASSFUL.key(8) === bits
end
address() click to toggle source

Returns the address portion of the IPv4 object as a string.

ip = IPAddress("172.16.100.4/22")

ip.address
  #=> "172.16.100.4"
# File lib/ipaddress/ipv4.rb, line 103
def address
  @address
end
arpa() click to toggle source
Alias for: reverse
b?() click to toggle source

Checks whether the ip address belongs to a RFC 791 CLASS B network, no matter what the subnet mask is.

Example:

ip = IPAddress("172.16.10.1/24")

ip.b?
  #=> true
# File lib/ipaddress/ipv4.rb, line 761
def b?
  CLASSFUL.key(16) === bits
end
bits() click to toggle source

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

ip = IPAddress("127.0.0.1")

ip.bits
  #=> "01111111000000000000000000000001"
# File lib/ipaddress/ipv4.rb, line 284
def bits
  data.unpack("B*").first
end
broadcast() click to toggle source

Returns the broadcast address for the given IP.

ip = IPAddress("172.16.10.64/24")

ip.broadcast.to_s
  #=> "172.16.10.255"
# File lib/ipaddress/ipv4.rb, line 296
def broadcast
  self.class.parse_u32(broadcast_u32, @prefix)
end
broadcast_u32() click to toggle source

Returns the broadcast address in Unsigned 32bits format

ip = IPaddress("10.0.0.1/29")

ip.broadcast_u32
  #=> 167772167
# File lib/ipaddress/ipv4.rb, line 517
def broadcast_u32
  network_u32 + size - 1
end
c?() click to toggle source

Checks whether the ip address belongs to a RFC 791 CLASS C network, no matter what the subnet mask is.

Example:

ip = IPAddress("192.168.1.1/30")

ip.c?
  #=> true
# File lib/ipaddress/ipv4.rb, line 777
def c?
  CLASSFUL.key(24) === bits
end
data() click to toggle source

Returns the address portion of an IPv4 object in a network byte order format.

ip = IPAddress("172.16.10.1/24")

ip.data
  #=> "\254\020\n\001"

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

a = Socket.open(params) # socket details here
ip = IPAddress("10.1.1.0/24")
binary_data = ["Address: "].pack("a*") + ip.data 

# Send binary data
a.puts binary_data
# File lib/ipaddress/ipv4.rb, line 252
def data
  [@u32].pack("N")
end
each() { |class.parse_u32(i, prefix)| ... } click to toggle source

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

The object yielded is a new IPv4 object created from the iteration.

ip = IPAddress("10.0.0.1/29")

ip.each do |i|
  p i.address
end
  #=> "10.0.0.0"
  #=> "10.0.0.1"
  #=> "10.0.0.2"
  #=> "10.0.0.3"
  #=> "10.0.0.4"
  #=> "10.0.0.5"
  #=> "10.0.0.6"
  #=> "10.0.0.7"
# File lib/ipaddress/ipv4.rb, line 422
def each
  (network_u32..broadcast_u32).each do |i|
    yield self.class.parse_u32(i, @prefix)
  end
end
each_host() { |class.parse_u32(i, prefix)| ... } click to toggle source

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

ip = IPAddress("10.0.0.1/29")

ip.each_host do |i|
  p i.to_s
end
  #=> "10.0.0.1"
  #=> "10.0.0.2"
  #=> "10.0.0.3"
  #=> "10.0.0.4"
  #=> "10.0.0.5"
  #=> "10.0.0.6"
# File lib/ipaddress/ipv4.rb, line 395
def each_host
  (network_u32+1..broadcast_u32-1).each do |i|
    yield self.class.parse_u32(i, @prefix)
  end
end
first() click to toggle source

Returns a new IPv4 object with the first host IP address in the range.

Example: given the 192.168.100.0/24 network, the first host IP address is 192.168.100.1.

ip = IPAddress("192.168.100.0/24")

ip.first.to_s
  #=> "192.168.100.1"

The object IP doesn't need to be a network: the method automatically gets the network number from it

ip = IPAddress("192.168.100.50/24")

ip.first.to_s
  #=> "192.168.100.1"
# File lib/ipaddress/ipv4.rb, line 350
def first
  self.class.parse_u32(network_u32+1, @prefix)
end
hosts() click to toggle source

Returns an array with the IP addresses of all the hosts in the network.

ip = IPAddress("10.0.0.1/29")

ip.hosts.map {|i| i.address}
  #=> ["10.0.0.1",
  #=>  "10.0.0.2",
  #=>  "10.0.0.3",
  #=>  "10.0.0.4",
  #=>  "10.0.0.5",
  #=>  "10.0.0.6"]
# File lib/ipaddress/ipv4.rb, line 493
def hosts
  to_a[1..-2]
end
include?(oth) click to toggle source

Checks whether a subnet includes the given IP address.

Accepts an IPAddress::IPv4 object.

ip = IPAddress("192.168.10.100/24")

addr = IPAddress("192.168.10.102/24")

ip.include? addr
  #=> true

ip.include? IPAddress("172.16.0.48/16")
  #=> false
# File lib/ipaddress/ipv4.rb, line 536
def include?(oth)
  @prefix <= oth.prefix and network_u32 == (oth.to_u32 & @prefix.to_u32)
end
include_all?(*others) click to toggle source

Checks whether a subnet includes all the given IPv4 objects.

ip = IPAddress("192.168.10.100/24")

addr1 = IPAddress("192.168.10.102/24")
addr2 = IPAddress("192.168.10.103/24")

ip.include_all?(addr1,addr2)
  #=> true
# File lib/ipaddress/ipv4.rb, line 552
def include_all?(*others)
  others.all? {|oth| include?(oth)}
end
last() click to toggle source

Like its sibling method #first, this method returns a new IPv4 object with the last host IP address in the range.

Example: given the 192.168.100.0/24 network, the last host IP address is 192.168.100.254

ip = IPAddress("192.168.100.0/24")

ip.last.to_s
  #=> "192.168.100.254"

The object IP doesn't need to be a network: the method automatically gets the network number from it

ip = IPAddress("192.168.100.50/24")

ip.last.to_s
  #=> "192.168.100.254"
# File lib/ipaddress/ipv4.rb, line 375
def last
  self.class.parse_u32(broadcast_u32-1, @prefix)
end
netmask() click to toggle source

Returns the prefix as a string in IP format

ip = IPAddress("172.16.100.4/22")

ip.netmask
  #=> "255.255.252.0"
# File lib/ipaddress/ipv4.rb, line 191
def netmask
  @prefix.to_ip
end
netmask=(addr) click to toggle source

Like #prefix=, this method allow you to change the prefix / netmask of an IP address object.

ip = IPAddress("172.16.100.4")

puts ip
  #=> 172.16.100.4/16

ip.netmask = "255.255.252.0"

puts ip
  #=> 172.16.100.4/22
# File lib/ipaddress/ipv4.rb, line 210
def netmask=(addr)
  @prefix = Prefix32.parse_netmask(addr)
end
network() click to toggle source

Returns a new IPv4 object with the network number for the given IP.

ip = IPAddress("172.16.10.64/24")

ip.network.to_s
  #=> "172.16.10.0"
# File lib/ipaddress/ipv4.rb, line 326
def network
  self.class.parse_u32(network_u32, @prefix)
end
network?() click to toggle source

Checks if the IP address is actually a network

ip = IPAddress("172.16.10.64/24")

ip.network?
  #=> false

ip = IPAddress("172.16.10.64/26")

ip.network?
  #=> true
# File lib/ipaddress/ipv4.rb, line 313
def network?
  @u32 | @prefix.to_u32 == @prefix.to_u32
end
network_u32() click to toggle source

Returns the network number in Unsigned 32bits format

ip = IPAddress("10.0.0.1/29")

ip.network_u32
  #=> 167772160
# File lib/ipaddress/ipv4.rb, line 505
def network_u32
  @u32 & @prefix.to_u32
end
octet(index) click to toggle source
Alias for: []
octets() click to toggle source

Returns the address as an array of decimal values

ip = IPAddress("172.16.100.4")

ip.octets
  #=> [172, 16, 100, 4]
# File lib/ipaddress/ipv4.rb, line 153
def octets
  @octets
end
prefix() click to toggle source

Returns the prefix portion of the IPv4 object as a IPAddress::Prefix32 object

ip = IPAddress("172.16.100.4/22")

ip.prefix
  #=> 22

ip.prefix.class
  #=> IPAddress::Prefix32
# File lib/ipaddress/ipv4.rb, line 119
def prefix
  @prefix
end
prefix=(num) click to toggle source

Set a new prefix number for the object

This is useful if you want to change the prefix to an object created with ::parse_u32 or if the object was created using the classful mask.

ip = IPAddress("172.16.100.4")

puts ip
  #=> 172.16.100.4/16

ip.prefix = 22

puts ip
  #=> 172.16.100.4/22
# File lib/ipaddress/ipv4.rb, line 141
def prefix=(num)
  @prefix = Prefix32.new(num)
end
private?() click to toggle source

Checks if an IPv4 address objects belongs to a private network RFC1918

Example:

ip = IPAddress "10.1.1.1/24"
ip.private?
  #=> true
# File lib/ipaddress/ipv4.rb, line 566
def private?
  [self.class.new("10.0.0.0/8"),
   self.class.new("172.16.0.0/12"),
   self.class.new("192.168.0.0/16")].any? {|i| i.include? self}
end
reverse() click to toggle source

Returns the IP address in in-addr.arpa format for DNS lookups

ip = IPAddress("172.16.100.50/24")

ip.reverse
  #=> "50.100.16.172.in-addr.arpa"
# File lib/ipaddress/ipv4.rb, line 581
def reverse
  @octets.reverse.join(".") + ".in-addr.arpa"
end
Also aliased as: arpa
size() click to toggle source

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

ip = IPAddress("10.0.0.1/29")

ip.size
  #=> 8
# File lib/ipaddress/ipv4.rb, line 475
def size
  2 ** @prefix.host_prefix
end
split(subnets=2) click to toggle source

Splits a network into different subnets

If the IP Address is a network, it can be divided into multiple networks. If self is not a network, this method will calculate the network from the IP and then subnet it.

If subnets is an power of two number, the resulting networks will be divided evenly from the supernet.

network = IPAddress("172.16.10.0/24")

network / 4   # implies map{|i| i.to_string}
  #=> ["172.16.10.0/26",
       "172.16.10.64/26",
       "172.16.10.128/26",
       "172.16.10.192/26"]

If num is any other number, the supernet will be divided into some networks with a even number of hosts and other networks with the remaining addresses.

network = IPAddress("172.16.10.0/24")

network / 3   # implies map{|i| i.to_string}
  #=> ["172.16.10.0/26",
       "172.16.10.64/26",
       "172.16.10.128/25"]

Returns an array of IPv4 objects

# File lib/ipaddress/ipv4.rb, line 618
def split(subnets=2)
  unless (1..(2**@prefix.host_prefix)).include? subnets
    raise ArgumentError, "Value #{subnets} out of range" 
  end
  networks = subnet(newprefix(subnets))
  until networks.size == subnets
    networks = sum_first_found(networks)
  end
  return networks
end
Also aliased as: /
subnet(subprefix) click to toggle source

This method implements the subnetting function similar to the one described in RFC3531.

By specifying a new prefix, the method calculates the network number for the given IPv4 object and calculates the subnets associated to the new prefix.

For example, given the following network:

ip = IPAddress "172.16.10.0/24"

we can calculate the subnets with a /26 prefix

ip.subnets(26).map{&:to_string)
  #=> ["172.16.10.0/26", "172.16.10.64/26", 
       "172.16.10.128/26", "172.16.10.192/26"]

The resulting number of subnets will of course always be a power of two.

# File lib/ipaddress/ipv4.rb, line 682
def subnet(subprefix)
  unless ((@prefix.to_i)..32).include? subprefix
    raise ArgumentError, "New prefix must be between #@prefix and 32"
  end
  Array.new(2**(subprefix-@prefix.to_i)) do |i|
    self.class.parse_u32(network_u32+(i*(2**(32-subprefix))), subprefix)
  end
end
supernet(new_prefix) click to toggle source

Returns a new IPv4 object from the supernetting of the instance network.

Supernetting is similar to subnetting, except that you getting as a result a network with a smaller prefix (bigger host space). For example, given the network

ip = IPAddress("172.16.10.0/24")

you can supernet it with a new /23 prefix

ip.supernet(23).to_string
  #=> "172.16.10.0/23"

However if you supernet it with a /22 prefix, the network address will change:

ip.supernet(22).to_string
  #=> "172.16.8.0/22"

If new_prefix is less than 1, returns 0.0.0.0/0

# File lib/ipaddress/ipv4.rb, line 654
def supernet(new_prefix)
  raise ArgumentError, "New prefix must be smaller than existing prefix" if new_prefix >= @prefix.to_i
  return self.class.new("0.0.0.0/0") if new_prefix < 1
  return self.class.new(@address+"/#{new_prefix}").network
end
to_i() click to toggle source
Alias for: u32
to_ipv6() click to toggle source

Return the ip address in a format compatible with the IPv6 Mapped IPv4 addresses

Example:

ip = IPAddress("172.16.10.1/24")

ip.to_ipv6
  #=> "ac10:0a01"
# File lib/ipaddress/ipv4.rb, line 792
def to_ipv6
  "%.4x:%.4x" % [to_u32].pack("N").unpack("nn")
end
to_s() click to toggle source

Returns a string with the address portion of the IPv4 object

ip = IPAddress("172.16.100.4/22")

ip.to_s
  #=> "172.16.100.4"
# File lib/ipaddress/ipv4.rb, line 166
def to_s
  @address
end
to_string() click to toggle source

Returns a string with the IP address in canonical form.

ip = IPAddress("172.16.100.4/22")

ip.to_string
  #=> "172.16.100.4/22"
# File lib/ipaddress/ipv4.rb, line 179
def to_string
  "#@address/#@prefix"
end
to_u32() click to toggle source
Alias for: u32
u32() click to toggle source

Returns the address portion in unsigned 32 bits integer format.

This method is identical to the C function inet_pton to create a 32 bits address family structure.

ip = IPAddress("10.0.0.0/8")

ip.to_i
  #=> 167772160
# File lib/ipaddress/ipv4.rb, line 227
def u32
  @u32
end
Also aliased as: to_i, to_u32