C:\Documents and Settings\administrator>tracert perlmonks.org

Tracing route to perlmonks.org [209.197.123.153]
over a maximum of 30 hops:

  1   <10 ms   <10 ms   <10 ms  SpeedTouch.lan [10.0.0.1]
  2    20 ms    10 ms    21 ms  bthg134-hg2.broadband.bt.net [217.32.6
8.201]
  3    20 ms    10 ms    20 ms  217.32.68.162
  4    10 ms    30 ms    20 ms  217.32.68.238
  5    10 ms    10 ms    20 ms  inh2cs01-601.btopenworld.com [62.7.250.129]
  6    21 ms    10 ms    20 ms  213.120.62.149
  7    10 ms    20 ms    30 ms  ^C
C:\Documents and Settings\administrator>

# so something simple like....

$tracert = `tracert google.com`;
@ips = $tracert =~ /(\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3})/g;
print "$_\n" for @ips;
print "External IP gateway is $ips[1]\n"; # or whatever index is correct