diff -Nur -x '*.orig' -x '*.rej' e-smith-base-4.18.0/root/usr/lib/perl5/site_perl/esmith/console/configure.pm mezzanine_patched_e-smith-base-4.18.0/root/usr/lib/perl5/site_perl/esmith/console/configure.pm
--- e-smith-base-4.18.0/root/usr/lib/perl5/site_perl/esmith/console/configure.pm	2007-04-27 15:09:31.000000000 -0400
+++ mezzanine_patched_e-smith-base-4.18.0/root/usr/lib/perl5/site_perl/esmith/console/configure.pm	2007-04-27 15:08:19.000000000 -0400
@@ -6,7 +6,7 @@
 use esmith::util::network qw(:all);
 use esmith::db;
 use esmith::ethernet;
-use Net::IPv4Addr qw(ipv4_network);
+use Net::IPv4Addr qw(:all);
 
 our @adapters;
 our $console;
@@ -1096,26 +1096,33 @@
 
     goto STATIC_NETMASK unless ($rc == 0);
 
-    if ($choice)
+    $choice ||= '';
+    my $error = undef;
+    if (!isValidIP($choice))
     {
-        if (isValidIP($choice) )
-        {
-            $db->set_value('GatewayIP', cleanIP($choice));
-            goto OTHER_PARAMETERS;
-        }
+	$error = "not a valid IP address";
     }
-    else
+    elsif (cleanIP($choice) eq $db->get_value('ExternalIP'))
     {
-        $choice = '';
+	$error = "address matches external interface address";
     }
+    elsif (!ipv4_in_network($db->get_value('ExternalIP'),
+	$db->get_value('ExternalNetmask'), "$choice/32"))
+    {
+	$error = "address is not local";
+    }
+    if ($error)
+    {
+	($rc, $choice) = $console->tryagain_page
+	    (
+	     title   => gettext("Invalid") . " - " . gettext($error),
+	     choice  => $choice,
+	    );
 
-    ($rc, $choice) = $console->tryagain_page
-        (
-         title   => gettext("Invalid gateway IP address"),
-         choice  => $choice,
-        );
-
-    goto STATIC_GATEWAY;
+	goto STATIC_GATEWAY;
+    }
+    $db->set_value('GatewayIP', cleanIP($choice));
+    goto OTHER_PARAMETERS;
 }
 
 #------------------------------------------------------------
@@ -1702,27 +1709,41 @@
 
     goto SYSTEM_MODE unless ($rc == 0);
 
-    if ($choice eq "")
+    $choice ||= '';
+    if (!$choice)
     {
         $db->delete('GatewayIP');
         $db->set_value('AccessType', 'off');
         goto OTHER_PARAMETERS;
     }
 
-    if ( isValidIP($choice) )
+    my $error = undef;
+    if (!isValidIP($choice))
     {
-        $db->set_value('GatewayIP', cleanIP($choice));
-        $db->set_value('AccessType', 'dedicated');
-        goto OTHER_PARAMETERS;
+	$error = "not a valid IP address";
     }
+    elsif (cleanIP($choice) eq $db->get_value('LocalIP'))
+    {
+	$error = "address matches local interface address";
+    }
+    elsif (!ipv4_in_network($db->get_value('LocalIP'),
+	$db->get_value('LocalNetmask'), "$choice/32"))
+    {
+	$error = "address is not local";
+    }
+    if ($error)
+    {
+	($rc, $choice) = $console->tryagain_page
+	    (
+	     title   => gettext("Invalid") . " - " . gettext($error),
+	     choice  => $choice,
+	    );
 
-    ($rc, $choice) = $console->tryagain_page
-        (
-         title   => gettext("Invalid gateway IP address"),
-         choice  => $choice,
-        );
-
-    goto SERVER_ONLY;
+	goto SERVER_ONLY;
+    }
+    $db->set_value('GatewayIP', cleanIP($choice));
+    $db->set_value('AccessType', 'dedicated');
+    goto OTHER_PARAMETERS;
 }
 
 #------------------------------------------------------------