Transfer of static routes to DHCP http://linuxconfig.net/manuals/howto/transfer-of-static-routes-to-dhcp.html

classless-route.pl

#!/usr/bin/perl
use strict;
# Usage:
# make_classless_option({ "subnet/mask" => "router", "subnet/mask" => "router", ... });
# subnet the subnet address, 4 dot-separated numbers
# mask the subnet mask length (e.g. /24 corresponds to 255.255.255.0, /8 corresponds to 255.0.0.0)
# router the router address, 4 dot-separated numbers
 
sub make_classless_option{
my $routes = shift;
my ($s1, $s2, $s3, $s4, $len, @bytes, $net, $mask, $destination, $router);
 
$len = 2;
@bytes = ();
foreach $destination(keys %{$routes}) {
($net, $mask) = split('/', $destination);
$router = $routes->{$destination};
($s1, $s2, $s3, $s4) = split(/\./, $net);
push(@bytes, sprintf('%02x', $mask));
push(@bytes, sprintf('%02x', $s1));
push(@bytes, sprintf('%02x', $s2)) if($mask > 8);
push(@bytes, sprintf('%02x', $s3)) if($mask > 16);
push(@bytes, sprintf('%02x', $s4)) if($mask > 24);
($s1, $s2, $s3, $s4) = split(/\./, $router);
push(@bytes, sprintf('%02x', $s1));
 push(@bytes, sprintf('%02x', $s2));
 push(@bytes, sprintf('%02x', $s3));
 push(@bytes, sprintf('%02x', $s4));
 }
 
 return join(':', @bytes);
 }
 
 # Example of use
 
 print make_classless_option({
 "10.230.0.0/16" => "10.230.178.145"
 });