diff --git a/perl-xCAT/xCAT/Utils.pm b/perl-xCAT/xCAT/Utils.pm
index bd47dcfb2..f49fb3253 100644
--- a/perl-xCAT/xCAT/Utils.pm
+++ b/perl-xCAT/xCAT/Utils.pm
@@ -4690,4 +4690,26 @@ sub is_process_exists{
     return 0;
 }
 
+#--------------------------------------------------------------------------------
+=head3  get_nmapversion
+      for nmap version 5.10 above, the sP option changed to sn.
+      the output of some commands also have differents.
+      example:  for snmp_scan option,
+        version 4.75 has output "Host 10.4.25.1 appears to be up ... good."  but
+        for version 6.40, it has output "Discovered open port 161/udp on 10.4.25.1"
+    Returns:
+      result: version of nmap on the system
+=cut
+#--------------------------------------------------------------------------------
+
+sub get_nmapversion {
+    my $nmap_version;
+    my $ccmd = "nmap -V | grep version";
+    my $result = xCAT::Utils->runcmd($ccmd, 0);
+    my @version_array = split / /, $result;
+    $nmap_version = $version_array[2];
+    return $nmap_version;
+}
+
+
 1;
diff --git a/xCAT-server/lib/xcat/plugins/bmcdiscover.pm b/xCAT-server/lib/xcat/plugins/bmcdiscover.pm
index 3f38db8bd..02469dde2 100644
--- a/xCAT-server/lib/xcat/plugins/bmcdiscover.pm
+++ b/xCAT-server/lib/xcat/plugins/bmcdiscover.pm
@@ -457,15 +457,12 @@ sub scan_process{
     ###########################################################
     if ( $method eq "nmap" ) {
         #check nmap version first
-        my $ccmd = "$nmap_path -V | grep version";
-        my $version_result = xCAT::Utils->runcmd($ccmd, 0);
-        my @version_array = split / /, $version_result;
-        my $nmap_version = $version_array[2];
+        my $nmap_version = xCAT::Utils->get_nmapversion();
         # the output of nmap is different for version under 5.10 
         if (xCAT::Utils->version_cmp($nmap_version,"5.10") < 0) {
             $bcmd = join(" ",$nmap_path," -sP -n $range | grep \"appears to be up\" |cut -d ' ' -f2 |tr -s '\n' ' ' ");
         } else {
-            $bcmd = join(" ",$nmap_path," -sn -n $range | grep \"Nmap scan report\" |cut -d ' ' -f5 |tr -s '\n' ' ' ");
+            $bcmd = join(" ",$nmap_path," -sn -n $range | grep -B1 up | grep \"Nmap scan report\" |cut -d ' ' -f5 |tr -s '\n' ' ' ");
         }
 
         $ip_list = xCAT::Utils->runcmd("$bcmd", -1);
diff --git a/xCAT-server/lib/xcat/plugins/switchdiscover.pm b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
index ccead4ce0..344997d2b 100644
--- a/xCAT-server/lib/xcat/plugins/switchdiscover.pm
+++ b/xCAT-server/lib/xcat/plugins/switchdiscover.pm
@@ -651,7 +651,7 @@ sub nmap_scan {
         }
     };
 
-    my $nmap_version = get_nmapversion($request);
+    my $nmap_version = xCAT::Utils->get_nmapversion();
     if (xCAT::Utils->version_cmp($nmap_version,"5.10") < 0) {
         $ccmd = "/usr/bin/nmap -sP -oX - @$ranges";
     } else {
@@ -828,8 +828,8 @@ sub snmp_scan {
 
     #use nmap to find if snmp port is enabled  
     # only open port will be scan
-    my $nmap_version = get_nmapversion($request);
-    if (xCAT::Utils->version_cmp($nmap_version,"5.10") <= 0) {
+    my $nmap_version = xCAT::Utils->get_nmapversion();
+    if (xCAT::Utils->version_cmp($nmap_version,"5.10") < 0) {
         $ccmd = "/usr/bin/nmap -P0 -v -sU -p 161 -oA snmp_scan @$ranges | grep up | grep good ";    
     } else {
         $ccmd = "/usr/bin/nmap -P0 -v -sU -p 161 -oA snmp_scan @$ranges | grep 'open port 161' ";    
@@ -856,7 +856,7 @@ sub snmp_scan {
     foreach my $line (@lines) {
         my @array = split / /, $line;
         my $ip;
-        if (xCAT::Utils->version_cmp($nmap_version,"4.75") <= 0) {
+        if (xCAT::Utils->version_cmp($nmap_version,"5.10") < 0) {
             $ip = $array[1];
         } else {
             $ip = $array[5];
@@ -1252,30 +1252,5 @@ sub format_xml {
     return ($xml);    
 }
 
-#--------------------------------------------------------------------------------
-=head3  get_nmapversion 
-      for nmap version 5.10 above, the sP option changed to sn.
-      the output of some commands also have differents.
-      example:  for snmp_scan option, 
-        version 4.75 has output "Host 10.4.25.1 appears to be up ... good."  but 
-        for version 6.40, it has output "Discovered open port 161/udp on 10.4.25.1"
-    Returns:
-      result: version of nmap on the system 
-=cut
-#--------------------------------------------------------------------------------
-
-sub get_nmapversion {
-    $request = shift;
-    my $nmap_version;
-    my $ccmd = "nmap -V | grep version";
-    my $result = xCAT::Utils->runcmd($ccmd, 0);
-    my @version_array = split / /, $result;
-    $nmap_version = $version_array[2];
-    if (exists($globalopt{verbose}))    {
-        send_msg($request, 0, "version of nmap: $nmap_version\n");
-    }
-    return $nmap_version;
-}
-
 1;