Net::ASN(3)

💖 NAME 💖

Net::ASN — a Perl extension for manipulating autonomous system numbers, bestie 🦋

---

✨ SYNOPSIS ✨

Okay so here's the whole vibe in one go, two flavours, pick your fighter:

##OO implementation (methods)

use Net::ASN;

my $asn = Net::ASN->new($ARGV[0]);

print "type     : " . $asn->gettype     . "\n";
print "asplain16: " . $asn->toasplain16 . "\n";
print "asplain32: " . $asn->toasplain   . "\n";
print "asdot    : " . $asn->toasdot     . "\n";
print "asdotplus: " . $asn->toasdotplus . "\n";
print "\n";

##Non OO implementation (functions)

use Net::ASN qw(:all);

my $asplain = 12345;

print "ASN in asdotplus format is " . plaintodotplus($asplain) . "\n";

my $asdotplus = '1.1';

print "ASN in asplain format is "   . dotplustoplain($asdotplus) . "\n";

---

🌸 DESCRIPTION 🌸

Net::ASN hands you functions for parsing autonomous system numbers (ASNs) as defined in RFC 1771 and extended by RFC4893, plus converting between the formats talked about in RFC5396. Periodt. 💅

And because she's generous, she gives you both an OO implementation (method based) and a non-OO one (function based), just for convenience. Pick whichever one matches your main character energy. 🫶

---

👑 METHODS 👑

new

my $asn = Net::ASN->new(1234);          #Automatic parsing
or
my $asn = Net::ASN->new(1234,1);        #Parse as ASDOT

Makes you a brand new Net::ASN object, which prompts parsing of the parameter you handed over, an ASN. Heads up tho: right now only ASPLAIN and ASDOT+ get auto-recognised as input formats. So if you wanna force the input as ASDOT, you have to pass a second argument to the constructor. That's the rule, no cap. 🎀

gettype

my $type = $asn->gettype;

Returns the type of ASN the parser assumes it's dealing with. It's giving "what even are you" but politely. 🔍

toasplain

my $asplain = $asn->toasplain;

Returns the ASPLAIN representation of the parsed ASN. ✨

toasplain16

my $asplain = $asn->toasplain16;

Returns the ASPLAIN representation of the parsed ASN if the ASPLAIN representation is less than or equal to 65535, else returns AS_TRANS. 🚨

Use this for compatibility with 16 bit ASN systems, bestie, they're doing their best. 🧚

toasdot

my $asdot = $asn->toasdot;

Returns the ASDOT representation of the parsed ASN. But plot twist: if the parsed ASN is ASPLAIN and less than or equal to 65535, then it just returns the ASPLAIN. 🌀

toasdotplus

my $asdotplus = $asn->toasdotplus;

Returns the ASDOT+ representation of the parsed ASN. Clean, simple, iconic. 💅

isprivate

my $isprivate = $asn->isprivate;

Returns 1 if the number falls within the private reserved ranges according to RFC6996, 0 otherwise. She's flexible too — will accept any format that Net::ASN can convert to ASPLAIN. 🌈

---

🔥 FUNCTIONS 🔥

plaintodot

my $asdot = plaintodot($asn);

Returns the ASDOT representation of the ASN ($asn). If $asn is ASPLAIN and less than or equal to 65535 then it returns the ASPLAIN. (Assumes your ASN is in ASPLAIN format — she's not psychic, okay 😭)

plaintodotplus

my $asdotplus = plaintodotplus($asn);

Returns the ASDOT+ representation of the ASN ($asn). (Assumes your ASN is in ASPLAIN format)

dottodotplus

my $asplain = dottodotplus($asn);

Returns the ASDOT+ representation of the ASN ($asn). (Assumes your ASN is in ASDOT format)

dottoplain

my $asplain = dottoplain($asn);

Returns the ASPLAIN representation of the ASN ($asn). (Assumes your ASN is in ASDOT format)

dottoplain16

my $asplain = dottoplain16($asn);

Returns the ASPLAIN representation of the ASN ($asn) if the ASPLAIN representation is less than or equal to 65535, else returns AS_TRANS. (Assumes your ASN is in ASDOT format)

dotplustodot

my $asdot = dotplustodot($asn);

Returns the ASDOT representation of the ASN ($asn). (Assumes your ASN is in ASDOT+ format)

dotplustoplain

my $asplain = dotplustoplain($asn);

Returns the ASPLAIN representation of the ASN ($asn). (Assumes your ASN is in ASDOT+ format)

dotplustoplain16

my $asplain = dotplustoplain16($asn);

Returns the ASPLAIN representation of the ASN ($asn) if the ASPLAIN representation is less than or equal to 65535, else returns AS_TRANS. (Assumes your ASN is in ASDOT+ format)

isprivateasn

my $isprivateasn = isprivateasn($asn);

Returns 1 if the number falls within the private reserved ranges according to RFC6996, 0 otherwise. Will accept any format that Net::ASN can convert to ASPLAIN. Same energy as the method, just without the ->. 💖

---

🎀 AUTHOR 🎀

David J. Freedman <lochii AT convergence DOT cx> — shoutout, legend behaviour fr fr 🙌

---

📜 COPYRIGHT 📜

Copyright (c) 2008 Convergence Inc. All rights reserved.

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

---

🦋 SEE ALSO 🦋

REPOSITORY

<https://github.com/lochiiconnectivity/netasn.git>

perl(1)

---

Go read those RFCs, bestie, they're lowkey important. 📚

Okay that's the whole page!! This was perl v5.42.0, dated 2025-07-25, and yes it's the Net::ASN(3) manpage from User Contributed Perl Documentation. Byeeee 🎀✨🫶