#!/usr/local/bin/perl -w
use strict;
use warnings;

use Net::Ping::External (qw(ping));

# 1 - автоматический режим переключение канала
# 2 - принудительное переключение на второй канал.
my $action = 1;
my $host_gw = "192.168.213.129"; # default gateway
my $gw = "192.168.178.209"; # backup gateway
my $now = localtime time;
my $log = "/var/log/route-change.log";


if($action == 1){


my $command = `netstat -rn | grep default`;
my @b = split('\s+',$command,3);


if (ping(hostname=>$host_gw, count=>5)){
   print "host $host_gw is ok\n";
       if($b[1] ne $host_gw){
           if($b[1] eq ""){
               `route add default $host_gw`;
           }else{
               `route change default $host_gw`;
               open(LOG,">>$log");
                   print LOG "[!] $now Route change to $host_gw\n";
               close(LOG);
           }
       }
}else{
   print "host $host_gw is bad.\n";
   if($b[1] ne $gw){
     `route change default $gw`;
   open(LOG,">>$log");
       print LOG "[!] $now Route change to $gw\n";
   close(LOG);
   }
}
}


if($action == 2){


my $command = `netstat -rn | grep default`;
my @b = split('\s+',$command,3);


if($b[1] ne $gw){
   if($b[1] eq ""){
       `route add default $gw`;
   }else{
       `route change default $gw`;
       open(LOG,">>/change_route.log");
           print LOG "[!] $now Route change to $gw\n";
       close(LOG);
   }
   }
}

# ipfw add 1 deny icmp from any to 192.168.213.129
00001 deny icmp from any to 192.168.213.129

# perl /usr/local/etc/route-change.pl
host 91.204.213.129 is bad.

# netstat -rn | grep default
default            192.168.178.209     UGS       521 51732384 vlan33

# ipfw 1 delete

# perl /usr/local/etc/route-change.pl
host 91.204.213.129 is ok

# netstat -rn | grep default
default            192.168.213.129     UGS       374 51751262 vlan32

# echo '# Route check and change' >> /etc/crontab

# echo '* * * * *       root    /usr/bin/perl /usr/local/etc/route-change.pl > /dev/null 2>&1' >> /etc/crontab

# killall -HUP cron