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IO::Socket::INET6 - Object interface for AF_INET|AF_INET6 domain sockets


    use IO::Socket::INET6;


IO::Socket::INET6 provides an object interface to creating and using sockets in either AF_INET or AF_INET6 domains. It is built upon the IO::Socket interface and inherits all the methods defined by IO::Socket.


new ( [ARGS] )

Creates an IO::Socket::INET6 object, which is a reference to a newly created symbol (see the Symbol package). new optionally takes arguments, these arguments are in key-value pairs.

In addition to the key-value pairs accepted by IO::Socket, IO::Socket::INET6 provides.

    Domain      Address family               AF_INET | AF_INET6 | AF_UNSPEC (default)
    PeerAddr    Remote host address          <hostname>[:<port>]
    PeerHost    Synonym for PeerAddr
    PeerPort    Remote port or service       <service>[(<no>)] | <no>
    LocalAddr   Local host bind address      hostname[:port]
    LocalHost   Synonym for LocalAddr
    LocalPort   Local host bind port         <service>[(<no>)] | <no>
    Proto       Protocol name (or number)    "tcp" | "udp" | ...
    Type        Socket type                  SOCK_STREAM | SOCK_DGRAM | ...
    Listen      Queue size for listen
    ReuseAddr   Set SO_REUSEADDR before binding
    Reuse       Set SO_REUSEADDR before binding (deprecated, prefer ReuseAddr)
    ReusePort   Set SO_REUSEPORT before binding
    Broadcast   Set SO_BROADCAST before binding
    Timeout     Timeout value for various operations
    MultiHomed  Try all adresses for multi-homed hosts
    Blocking    Determine if connection will be blocking mode

If Listen is defined then a listen socket is created, else if the socket type, which is derived from the protocol, is SOCK_STREAM then connect() is called.

Although it is not illegal, the use of MultiHomed on a socket which is in non-blocking mode is of little use. This is because the first connect will never fail with a timeout as the connect call will not block.

The PeerAddr can be a hostname, the IPv6-address on the "2001:800:40:2a05::10" form , or the IPv4-address on the "" form. The PeerPort can be a number or a symbolic service name. The service name might be followed by a number in parenthesis which is used if the service is not known by the system. The PeerPort specification can also be embedded in the PeerAddr by preceding it with a ":", and closing the IPv6 address on bracktes "[]" if necessary: "124.678.12.34:23","[2a05:345f::10]:23","".

If Domain is not given, AF_UNSPEC is assumed, that is, both AF_INET and AF_INET6 will be both considered when resolving DNS names. AF_INET6 is prioritary. If you guess you are in trouble not reaching the peer,(the service is not available via AF_INET6 but AF_INET) you can either try Multihomed (try any address/family until reach) or concrete your address family (AF_INET, AF_INET6).

If Proto is not given and you specify a symbolic PeerPort port, then the constructor will try to derive Proto from the service name. As a last resort Proto "tcp" is assumed. The Type parameter will be deduced from Proto if not specified.

If the constructor is only passed a single argument, it is assumed to be a PeerAddr specification.

If Blocking is set to 0, the connection will be in nonblocking mode. If not specified it defaults to 1 (blocking mode).


   $sock = IO::Socket::INET6->new(PeerAddr => '',
                                 PeerPort => 'http(80)',
                                 Proto    => 'tcp');

Suppose either you have no IPv6 connectivity or has no http service on IPv6. Then,

(Trying all address/families until reach)

   $sock = IO::Socket::INET6->new(PeerAddr => '',
                                 PeerPort => 'http(80)',
                                 Multihomed => 1 ,
                                 Proto    => 'tcp');

(Concrete to IPv4 protocol)

   $sock = IO::Socket::INET6->new(PeerAddr => '',
                                 PeerPort => 'http(80)',
                                 Domain => AF_INET ,
                                 Proto    => 'tcp');

   $sock = IO::Socket::INET6->new(PeerAddr => 'localhost:smtp(25)');

   $sock = IO::Socket::INET6->new(Listen    => 5,
                                 LocalAddr => 'localhost',
                                 LocalPort => 9000,
                                 Proto     => 'tcp');

   $sock = IO::Socket::INET6->new('[::1]:25');

   $sock = IO::Socket::INET6->new(PeerPort  => 9999,
                                 PeerAddr  => inet_ntop(AF_INET6,in6addr_broadcast),
                                 Proto     => udp,    
                                 LocalAddr => 'localhost',
                                 Broadcast => 1 ) 
                             or die "Can't bind : $@\n";


As of VERSION 1.18 all IO::Socket objects have autoflush turned on by default. This was not the case with earlier releases.



sockport ()

Return the port number that the socket is using on the local host

sockhost ()

Return the address part of the sockaddr structure for the socket in a text form ("2001:800:40:2a05::10" or "")

peerport ()

Return the port number for the socket on the peer host.

peerhost ()

Return the address part of the sockaddr structure for the socket on the peer host in a text form ("2001:800:40:2a05::10" or "")


Socket,Socket6, IO::Socket


This program is based on IO::Socket::INET by Graham Barr <> and currently maintained by the Perl Porters.

Modified by Rafael Martinez Torres <> and Euro6IX project.


Copyright (c) 2003- Rafael Martinez Torres <>.

Copyright (c) 2003- Euro6IX project.

Copyright (c) 1996-8 Graham Barr <>.

All rights reserved.

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.