NAME

Net::BGP::NLRI - Class encapsulating BGP-4 NLRI information

SYNOPSIS

    use Net::BGP::NLRI qw( :origin );

    # Constructor
    $nlri = Net::BGP::NLRI->new(
        Aggregator      => [ 64512, '10.0.0.1' ],
        AtomicAggregate => 1,
        AsPath          => Net::BGP::ASPath->new("64512 64513 64514"),
        Communities     => [ qw( 64512:10000 64512:10001 ) ],
        LocalPref       => 100,
        MED             => 200,
        NextHop         => '10.0.0.1',
        Origin          => INCOMPLETE,
    );

    # Object Copy
    $clone = $nlri->clone();

    # Accessor Methods
    $aggregator_ref   = $nlri->aggregator($aggregator_ref);
    $atomic_aggregate = $nlri->atomic_aggregate($atomic_aggregate);
    $as_path          = $nlri->as_path($as_path);
    $communities_ref  = $nlri->communities($communities_ref);
    $local_pref       = $nlri->local_pref($local_pref);
    $med              = $nlri->med($med);
    $next_hop         = $nlri->next_hop($next_hop);
    $origin           = $nlri->origin($origin);
    $string           = $nlri->asstring;

    # Preference Comparisons
    if ($nlri1  < $nlri2) { ... };
    if ($nlri1  > $nlri2) { ... };
    if ($nlri1 == $nlri2) { ... };
    if ($nlri1 != $nlri2) { ... };
    @sorted = sort { $a <=> $b } ($nlri1, $nlri2, $nlri3, ... );

    # Comparison
    if ($nlri1 eq $nlri2) { ... };
    if ($nlri1 ne $nlri2) { ... };

DESCRIPTION

This module encapsulates the data used by BGP-4 to represent network reachability information. It provides a constructor, and accessor methods for each of the well-known path attributes. A BGP-4 UPDATE message includes this information along with a list of networks for which the information should be used (and a list of networks no longer accessible). See Net::BGP::Update for more infomration.

CONSTRUCTOR

new() - create a new Net::BGP::NLRI object

    $nlri = Net::BGP::NLRI->new(
        Aggregator      => [ 64512, '10.0.0.1' ],
        AsPath          => Net::BGP::ASPath->new("64512 64513 64514"),
        AtomicAggregate => 1,
        Communities     => [ qw( 64512:10000 64512:10001 ) ],
        LocalPref       => 100,
        MED             => 200,
        NextHop         => '10.0.0.1',
        Origin          => INCOMPLETE,
    );

This is the constructor for Net::BGP::NLRI objects. It returns a reference to the newly created object. The following named parameters may be passed to the constructor. See RFC 1771 for the semantics of each path attribute.

Aggregator

This parameter corresponds to the AGGREGATOR path attribute. It is expressed as an array reference, the first element of which is the AS number (in the range of an 16-bit unsigned integer) of the route aggregator, and the second element is the aggregator's IP address expressed in dotted-decimal notation as a string. It may be omitted, in which case no AGGREGATOR path attribute will be attached to the UPDATE message.

AsPath

This parameter corresponds to the AS_PATH path attribute. The AS_PATH is expressed as an Net::BGP::ASPath object. If expressed otherwise, a Net::BGP::ASPath object is tried to be constructed using the argument.

AtomicAggregate

This parameter corresponds to the ATOMIC_AGGREGATE path attribute. It is a boolean value so any value which perl interprets as true/false may be used. It may be omitted, in which case no ATOMIC_AGGREGATE path attribute will be attached to the UPDATE message.

Communities

This parameter corresponds to the COMMUNITIES attribute defined in RFC 1997. It is expressed as an array reference of communities which apply to the route(s). The communities are encoded in a special format: AAAA:CCCC, where AAAA corresponds to the 16-bit unsigned integer AS number, and CCCC is a 16-bit unsigned integer of arbitrary value. But see RFC 1997 for the semantics of several reserved community values. This attribute may be omitted, in which case no COMMUNITIES attribute will be attached to the UPDATE message.

LocalPref

This parameter corresponds to the LOCAL_PREF path attribute. It is expressed as a 32-bit unsigned integer scalar value. It may be omitted, in which case no LOCAL_PREF path attribute will be attached to the UPDATE message.

MED

This parameter corresponds to the MULTI_EXIT_DISC path attribute. It is expressed as a 32-bit unsigned integer scalar value. It may be omitted, in which case no MULTI_EXIT_DISC path attribute will be attached to the UPDATE message.

NextHop

This parameter corresponds to the NEXT_HOP path attribute. It is expressed as a dotted-decimal IP address as a perl string. This path attribute is mandatory and the parameter must always be provided to the constructor.

Origin

This parameter corresponds to the ORIGIN path attribute. It is expressed as an integer scalar value, which can take the following enumerated values: IGP, EGP, or INCOMPLETE. The preceding symbols can be imported into the program namespace individually or by the :origin export tag. This path attribute is mandatory and the parameter must always be provided to the constructor.

OBJECT COPY

clone() - clone a Net::BGP::NLRI object

    $clone = $nlri->clone();

This method creates an exact copy of the Net::BGP::NLRI object with Path Attributes fields matching those of the original object.

ACCESSOR METHODS

aggregator()

as_path()

atomic_aggregate()

communities()

local_pref()

med()

next_hop()

origin()

These accessor methods return the value(s) of the associated path attribute fields if called with no arguments. If called with arguments, they set the associated field. The representation of parameters and return values is the same as described for the corresponding named constructor parameters above.

asstring()

This accessor method returns a print-friendly string with some, but not all, of the information contained in the object.

EXPORTS

The module exports the following symbols according to the rules and conventions of the Exporter module.

:origin IGP, EGP, INCOMPLETE

SEE ALSO

Net::BGP

Net::BGP::Process

Net::BGP::Peer

Net::BGP::Update

Net::BGP::Refresh

Net::BGP::ASPath

Net::BGP::Notification

AUTHOR

Stephen J. Scheck <sscheck@cpan.org>

cpanm Net::BGP

perl -MCPAN -e shell
install Net::BGP