diff --git a/xCAT-server/lib/xcat/plugins/blade.pm b/xCAT-server/lib/xcat/plugins/blade.pm
index 6fe41a86e..088bd09ac 100644
--- a/xCAT-server/lib/xcat/plugins/blade.pm
+++ b/xCAT-server/lib/xcat/plugins/blade.pm
@@ -4370,7 +4370,7 @@ sub process_request {
     }
   }
   if ($request->{command}->[0] eq "findme") {
-    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]))  {
+    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]) and ($request->{discoverymethod}->[0] ne 'undef'))  {
         # The findme request had been processed by other module, just return
         return;
     }
diff --git a/xCAT-server/lib/xcat/plugins/hpblade.pm b/xCAT-server/lib/xcat/plugins/hpblade.pm
index 6328f8b95..e6cd569ff 100755
--- a/xCAT-server/lib/xcat/plugins/hpblade.pm
+++ b/xCAT-server/lib/xcat/plugins/hpblade.pm
@@ -685,7 +685,7 @@ sub process_request {
 		}
 	}
 	if ($request->{command}->[0] eq "findme") {
-                if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]))  {
+                if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]) and ($request->{discoverymethod}->[0] ne 'undef'))  {
                     # The findme request had been processed by other module, just return
                     return;
                 }
diff --git a/xCAT-server/lib/xcat/plugins/profilednodes.pm b/xCAT-server/lib/xcat/plugins/profilednodes.pm
index 242216f82..54ca1f3ca 100644
--- a/xCAT-server/lib/xcat/plugins/profilednodes.pm
+++ b/xCAT-server/lib/xcat/plugins/profilednodes.pm
@@ -1816,7 +1816,7 @@ Usage:
 
 #-------------------------------------------------------
 sub findme{
-    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]))  {
+    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]) and ($request->{discoverymethod}->[0] ne 'undef'))  {
         # The findme request had been processed by other module, just return
         return;
     }
diff --git a/xCAT-server/lib/xcat/plugins/seqdiscovery.pm b/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
index 87d1d5281..96735ecf2 100755
--- a/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
+++ b/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
@@ -54,7 +54,7 @@ sub findme {
     my @SEQdiscover = xCAT::TableUtils->get_site_attribute("__SEQDiscover");
     my @PCMdiscover = xCAT::TableUtils->get_site_attribute("__PCMDiscover");
     
-    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]))  {
+    if (defined($request->{discoverymethod}) and defined($request->{discoverymethod}->[0]) and ($request->{discoverymethod}->[0] ne 'undef'))  {
         # The findme request had been processed by other module, just return
         return;
     }
diff --git a/xCAT-server/lib/xcat/plugins/switch.pm b/xCAT-server/lib/xcat/plugins/switch.pm
index 12024e6d1..c23543255 100644
--- a/xCAT-server/lib/xcat/plugins/switch.pm
+++ b/xCAT-server/lib/xcat/plugins/switch.pm
@@ -268,7 +268,7 @@ sub process_request {
         }
         return;
     } elsif ($req->{command}->[0] eq 'findme') {
-        if (defined($req->{discoverymethod}) and defined($req->{discoverymethod}->[0]))  {
+        if (defined($req->{discoverymethod}) and defined($req->{discoverymethod}->[0]) and ($req->{discoverymethod}->[0] ne 'undef'))  {
             # The findme request had been processed by other module, just return
             return;
         }
diff --git a/xCAT-server/lib/xcat/plugins/typemtms.pm b/xCAT-server/lib/xcat/plugins/typemtms.pm
index 53e5cc29d..8a9b350f4 100644
--- a/xCAT-server/lib/xcat/plugins/typemtms.pm
+++ b/xCAT-server/lib/xcat/plugins/typemtms.pm
@@ -57,7 +57,7 @@ sub process_request {
     my $cb = shift;
     my $doreq = shift;
     if ($req->{command}->[0] eq 'findme') {
-        if (defined($req->{discoverymethod}) and defined($req->{discoverymethod}->[0]))  {
+        if (defined($req->{discoverymethod}) and defined($req->{discoverymethod}->[0]) and ($req->{discoverymethod}->[0] ne 'undef'))  {
             # The findme request had been processed by other module, just return
             return;
         }
diff --git a/xCAT-server/lib/xcat/plugins/zzzdiscovery.pm b/xCAT-server/lib/xcat/plugins/zzzdiscovery.pm
index 643b178c8..a39f2344f 100644
--- a/xCAT-server/lib/xcat/plugins/zzzdiscovery.pm
+++ b/xCAT-server/lib/xcat/plugins/zzzdiscovery.pm
@@ -18,7 +18,7 @@ sub process_request {
     my $doreq = shift;
     if ($req->{command}->[0] eq 'findme') {
         xCAT::MsgUtils->message("S", "xcat.discovery.zzzdiscovery: ($req->{mtm}->[0]*$req->{serial}->[0]) Finish to process the discovery request");
-        if (!defined($req->{discoverymethod}) or !defined($req->{discoverymethod}->[0]))  {
+        if (!defined($req->{discoverymethod}) or !defined($req->{discoverymethod}->[0]) or ($req->{discoverymethod}->[0] eq 'undef'))  {
             my $rsp = {};
             $rsp->{error}->[0] = "The discovery request can not be processed";
             $cb->($rsp);