Even tho Piercer has his answer in Net::GrpNetworks, here is something I whipped up for NT/2K. It's modeled after *nix ifconfig command, as I detest having to scroll though the output of ipconfig on my multi-homed hosts. Note that the ifno ( i.e. eth0 ) is a totally made-up identifier. I planned on making the identifier more like 'windump -D''s output, but never got to it.

This ifconfig takes no options.

#!/usr/bin/perl -w
#-*-perl-*-

use strict;
use Win32::TieRegistry;
use Net::Netmask;
use Socket;


my %card;
my %regKeys;
$Registry->Delimiter("/");
my $network     = $Registry->{"LMachine/Software/Microsoft/Windows NT/
+"};
$network        = $network->{"CurrentVersion/NetworkCards/"};
my %cardInfo;
my $netCard;

foreach ( keys %$network ) {
  my $foo       = $network->{$_};
    $card{$foo->GetValue('ServiceName')} = $foo->GetValue('Description
+');
}

foreach $netCard ( keys %card ) {
  my $Key       = $Registry->{"/LMachine/SYSTEM/CurrentControlSet/Serv
+ices/"};
  $Key          = $Key->{"Tcpip/Parameters/Interfaces/$netCard/"};

  $cardInfo{'dhcp'}         = $Key->GetValue("EnableDHCP");

  if ( $cardInfo{'dhcp'} eq "0x00000000" ) {
    $cardInfo{'ipAddr'}     = $Key->GetValue("IPAddress");
    $cardInfo{'mask'}       = $Key->GetValue("SubnetMask");
    $cardInfo{'domain'}     = $Key->GetValue("Domain") || "";
    $cardInfo{'nameServer'} = $Key->GetValue("NameServer") || "";
    $cardInfo{'dhcp'}       = 'no';
    $cardInfo{'gateway'}    = $Key->GetValue("DefaultGateway") || "";
    $cardInfo{'metric'}     = $Key->GetValue("DefaultGatewayMetric")
               || '1';
  }
  else {
    $cardInfo{'ipAddr'}     = $Key->GetValue("DhcpIPAddress");
    $cardInfo{'mask'}       = $Key->GetValue("DhcpSubnetMask");
    $cardInfo{'domain'}     = $Key->GetValue("DhcpDomain") || "";
    $cardInfo{'nameServer'} = $Key->GetValue("DhcpNameServer") || "";
    $cardInfo{'dhcp'}       = 'yes';
    $cardInfo{'gateway'}    = $Key->GetValue("DhcpDefaultGateway") || 
+"";
    $cardInfo{'metric'}     = $Key->GetValue("DhcpDefaultGatewayMetric
+")
               || '1';
  }
  $cardInfo{'ipAddr'}       = removePad ( $cardInfo{'ipAddr'} );
  $cardInfo{'mask'}         = removePad ( $cardInfo{'mask'} );
  my $block                 = new Net::Netmask ( 
                        $cardInfo{'ipAddr'},
                        $cardInfo{'mask'}
                           );
  $cardInfo{'broadcast'}    = $block->broadcast();
  $cardInfo{'mtu'}          = $Key->GetValue("MTU") || 1500;

  my $type      = $Registry->{"LMachine/SYSTEM/CurrentControlSet/Contr
+ol/"};
  $type         = $type->{"Class/{4D36E972-E325-11CE-BFC1-08002BE10318
+}"};
  my @members   = $type->SubKeyNames;
  foreach ( @members ) {
    my $corge   = $type->{"$_"};
    if ( $corge->GetValue("NetCfgInstanceId") eq $netCard ) {
      $cardInfo{'flags'}    = $corge->GetValue("Characteristics");
      my $baz   = $corge->{"Ndi/Interfaces/"};
      $cardInfo{'media'}    = $baz->GetValue("LowerRange");
      $cardInfo{'ifno'}     = $_;
      $cardInfo{'ifno'}     =~ s/^0+//;
      $cardInfo{'ifno'}     = 0
    if $cardInfo{'ifno'} eq "";
      $cardInfo{'ifno'}     = ( substr $cardInfo{'media'}, 0, 3 ) . $c
+ardInfo{'ifno'};
    }
  }
  my $netBt     = $Registry->{"LMachine/SYSTEM/CurrentControlSet/Servi
+ces/"};
  $netBt        = $netBt->{"NetBT/Parameters/Interfaces/Tcpip_$netCard
+/"};
  $cardInfo{'wins'}         = $netBt->GetValue("NameServerList") || ""
+;
  write;
}

undef $Registry;
exit 0;

format STDOUT =

@>>>>: @<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+<<<<<<<<
$cardInfo{'ifno'},$card{$netCard}
          Link encap:@<<<<<<<<<<<<< DHCP:@<<  flags:@<<<<<<<<<<<<<<<<<
+< 
                     $cardInfo{'media'},              $cardInfo{'dhcp'
+},    $cardInfo{'flags'}
          inet addr:@<<<<<<<<<<<<<< Bcast:@<<<<<<<<<<<<<< Mask:@<<<<<<
+<<<<<<<<<
                    $cardInfo{'ipAddr'},                  $cardInfo{'b
+roadcast'},          $cardInfo{'mask'}
          gateway:@<<<<<<<<<<<<<<<< MTU:@<<<  Metric:@<<< WINS:@<<<<<<
+<<<<<<<<<
                  $cardInfo{'gateway'},             $cardInfo{'mtu'}, 
+       $cardInfo{'metric'},  $cardInfo{'wins'}
          domain:@<<<<<<<<<<<<<<<<< DNS:@<<<<<<<<<<<<<<<<<<<<<<<<<<<<<
+<
                 $cardInfo{'domain'},               $cardInfo{'nameSer
+ver'}
.



sub removePad {
  my $value = shift;
  $value =~ s/\x00+$//;
  return $value;
}
__END__
[download]

Anyway, it's an old script. A little digging in TechNet may make it more portable w/i M$ boxen. I know Solaris has it's '/etc/defaultrouter' file which can give the info ( if dynamic routing isn't in play ).

Another, more portable - non-perl, way is the 'netstat -r' command, and parse the output for 'default' or '0.0.0.0'. netstat should work on any TCP/IP enabled host ( YMMV ).

HTH
--
idnopheq
Apply yourself to new problems without preparation, develop confidence in your ability to to meet situations as they arrise.

~ Shunryu Suzuki

How about using Net::Traceroute and using the output to give you the default GW?

Clare

Sounds good, I'll try it out. Thanks

net:traceroute doesn't seem to support Windoze - however I found Net::GrpNetworks which looks like it should do the trick. Cheers.