Comments on: How to get local routing(BGP) info for South Africa

By: Jaco

Jaco — Mon, 15 Aug 2011 10:43:24 +0000

Mod on Script:
1) Use Saix server
2) Display only destination subnet
3) Add standard prefix where required

#!/usr/bin/perl

use Net::Telnet;

$prompt=’/tpr-route-server>/’;

$server=”tpr-route-server.saix.net”;

$saix_cmd=”show ip bgp community 5713:56225\n”;

print “Connecting to $server\n”;
my $session = Net::Telnet->new(Host => $server,Prompt => $prompt,Timeout=>30);
unlink(“t.log”);
$session->dump_log(“t.log”);
$session->login(“saix”, “saix”);

#turn off paging
$session->cmd(“terminal length 0″);

#get list of local routes
print “Retrieving BGP routes\n”;
my @output = $session->cmd($saix_cmd);
foreach (@output) {
@fields = split(/\s+/);
$fields[1] =~ s/^i//;
@parts = split(/\./, $fields[1]);
if ($parts[3] =~ /\//) {
print $fields[1] . “\n”;
} elsif ($parts[0] < 128) {
print $fields[1] . "/8\n";
} elsif ($parts[0] < 192) {
print $fields[1] . "/16\n";
} elsif ($parts[0] close;

By: xarion

xarion — Mon, 06 Jul 2009 08:27:58 +0000

Awesome, I found that the server now reports a: “local-route-server” prompt so for whoever wants to use the script just needs to change $prompt = ‘/public-route-server>/’; to $prompt = ‘/local-route-server>/’; How do I spew out just the address not all the other columns?

By: roelf

roelf — Fri, 27 Feb 2009 22:33:37 +0000

Hi Rod. A subnet without a mask means that it’s a “standard” class prefix. E.g. you can assume /24 for the 196.3.161.0 subnet, or /8 for a 21.23.0.0 subnet. It’s a bit schizophrenic I must admit.

By: rodch

rodch — Wed, 25 Feb 2009 01:17:16 +0000

Hi,
Thanks for this.

BTW. Some of the \n nl chars in your perl script lost their \.(As seen by me in FFox)

To reduce the size, I tried running the list through a couple of cidr subnet aggregators, which fail variously.

I am cisco-illiterate, Any idea what a subnet like 196.3.161.0 , (without mask bits) means? One aggregator tries 196.3.161.0/32 another barfs with “line too long”

A quick ping scan tells me there are live hosts within the 196.3.161.0/24 space.