diff --git a/xCAT-server/lib/xcat/plugins/switchdiscover.pm b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
index 2433d4154..cee804d59 100644
--- a/xCAT-server/lib/xcat/plugins/switchdiscover.pm
+++ b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
@@ -721,6 +721,7 @@ sub nmap_scan {
                 my $mac;
                 if (exists($host->{address})) {
                     my $addr_ref = $host->{address};
+                    $found = 0;
                     foreach my $addr ( @$addr_ref ) {
                         my $type = $addr->{addrtype};
                         if ( $type ne "mac" ) {
@@ -767,7 +768,7 @@ sub nmap_scan {
         }
     }
 
-    if (!$osguess_ips) {
+    if ($osguess_ips) {
         my $guess_switches = nmap_osguess($request, $osguess_ips);
         foreach my $guess_mac ( keys %$guess_switches ) {
             $switches->{$guess_mac}->{ip} = $guess_switches->{$guess_mac}->{ip};;
@@ -1385,7 +1386,6 @@ sub matchPredefineSwitch {
     my $sub_req = shift;
     my $discoverswitch;
     my $configswitch;
-    my $static_ip;
 
     #print Dumper($outhash);
     my $macmap = xCAT::MacMap->new();
@@ -1411,8 +1411,6 @@ sub matchPredefineSwitch {
             next;
         }
 
-        # get predefine node ip address
-        $static_ip = xCAT::NetworkUtils->getipaddr($node);
         my $stype = get_switchtype($vendor);
 
         send_msg($request, 0, "Switch discovered and matched: $dswitch to $node" );
diff --git a/xCAT-server/share/xcat/scripts/configBNT b/xCAT-server/share/xcat/scripts/configBNT
index 0c4059236..fda59767a 100755
--- a/xCAT-server/share/xcat/scripts/configBNT
+++ b/xCAT-server/share/xcat/scripts/configBNT
@@ -118,7 +118,7 @@ sub config_ip {
     my @config_switches;
     my @discover_switches;
     my $nodetab = xCAT::Table->new('hosts');
-    my $nodehash = $nodetab->getNodesAttribs(\@nodes,['ip','otherinterfaces','mac']);
+    my $nodehash = $nodetab->getNodesAttribs(\@nodes,['ip','otherinterfaces']);
     # get netmask from network table
     my $nettab = xCAT::Table->new("networks");
     my @nets;
@@ -184,6 +184,7 @@ sub config_ip {
         foreach my $net (@nets) {
             if (xCAT::NetworkUtils::isInSameSubnet( $net->{'net'}, $static_ip, $net->{'mask'}, 0)) {
                 $mask=$net->{'mask'};
+                last;
             }
         }