diff --git a/xCAT-server/lib/perl/xCAT/PPC.pm b/xCAT-server/lib/perl/xCAT/PPC.pm
index 95063a76c..bd02042c7 100644
--- a/xCAT-server/lib/perl/xCAT/PPC.pm
+++ b/xCAT-server/lib/perl/xCAT/PPC.pm
@@ -2142,38 +2142,21 @@ sub findme {
     my $request = shift;
     my $callback = shift;
     my $subreq = shift;
-    my $vpdtab = xCAT::Table->new('vpd');
     if (!defined $request->{'mtm'} or !defined $request->{'serial'}) {
         xCAT::MsgUtils->message("S", "Discovery Error: 'mtm' or 'serial' not found.");
         return;
     }
-    unless ($vpdtab)  {
-        xCAT::MsgUtils->message("S", "Discovery Error: Could not open table: vpd.");
-        return;
-    }
     my @attr_array = ();
-    push @attr_array, "mtm==$request->{mtm}->[0]";
-    push @attr_array, "serial==$request->{serial}->[0]";
-
-    my @tmp_nodes = $vpdtab->getAllAttribsWhere(\@attr_array, 'node');
+    my $mtms = $request->{'mtm'}->[0]."*".$request->{'serial'}->[0]; 
+    my $tmp_nodes = $::XCATVPDHASH{$mtms};
     my @nodes = ();
     my $pbmc_node;
-    my %nodes_hash = ();
-    foreach (@tmp_nodes) {
-        $nodes_hash{$_->{node}} = '1';
-    }
-    @nodes = keys (%nodes_hash);
-    # remove the pbmc node defined by lsslp from the node groups
-    my $ppctab = xCAT::Table->new('ppc');
-    if ($ppctab) {
-        my $ppchash = $ppctab->getNodesAttribs(\@nodes, ['node', 'nodetype']);
-        foreach (@nodes) {
-            if (defined($ppchash->{$_}->[0]) && defined($ppchash->{$_}->[0]->{'nodetype'}) && $ppchash->{$_}->[0]->{'nodetype'} eq 'pbmc') {
-                delete $nodes_hash{$_};
-                $pbmc_node = $_;
-            }
+    foreach (@$tmp_nodes) {
+        if ($::XCATPPCHASH{$_}) {
+            $pbmc_node = $_;
+        } else {
+            push @nodes, $_;
         }
-        @nodes = keys (%nodes_hash);
     }
     my $nodenum = $#nodes;
     if ($nodenum < 0) {
diff --git a/xCAT-server/lib/xcat/plugins/seqdiscovery.pm b/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
index 590071920..60577d5de 100755
--- a/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
+++ b/xCAT-server/lib/xcat/plugins/seqdiscovery.pm
@@ -130,6 +130,17 @@ sub findme {
             $node = $allnodes[0];
         }
     }
+    my $pbmc_node = undef;
+    if ($request->{'mtm'}->[0] and $request->{'serial'}->[0]) {
+        my $mtms = $request->{'mtm'}->[0]."*".$request->{'serial'}->[0];
+        my $tmp_nodes = $::XCATVPDHASH{$mtms};
+        foreach (@$tmp_nodes) {
+            if ($::XCATPPCHASH{$_}) {
+                $pbmc_node = $_;
+            }
+        } 
+    }
+
 
     if ($node) {
         my $skiphostip;
@@ -363,8 +374,13 @@ sub findme {
         }
 
         # call the discovered command to update the discovery request to a node
+         
         $request->{command}=['discovered'];
         $request->{noderange} = [$node];
+        if ($pbmc_node) {
+            $request->{pbmc_node} = [$pbmc_node];
+        }
+
         $request->{discoverymethod} = ['sequential'];
         $request->{updateswitch} = ['yes'];
         $subreq->($request); 
diff --git a/xCAT-server/lib/xcat/plugins/switch.pm b/xCAT-server/lib/xcat/plugins/switch.pm
index 29b00a4bc..bf86a3875 100644
--- a/xCAT-server/lib/xcat/plugins/switch.pm
+++ b/xCAT-server/lib/xcat/plugins/switch.pm
@@ -157,6 +157,16 @@ sub process_request {
 		if ($node) { last; }
 	    }
 	}
+        my $pbmc_node = undef;
+        if ($req->{'mtm'}->[0] and $req->{'serial'}->[0]) {
+            my $mtms = $req->{'mtm'}->[0]."*".$req->{'serial'}->[0];
+            my $tmp_nodes = $::XCATVPDHASH{$mtms};
+            foreach (@$tmp_nodes) {
+                if ($::XCATPPCHASH{$_}) {
+                    $pbmc_node = $_;
+                }
+            } 
+        }
 	 
 	if ($node) {
 	    my $mactab = xCAT::Table->new('mac',-create=>1);
@@ -169,6 +179,9 @@ sub process_request {
 	    #$doreq->(\%request);
 	    $req->{command}=['discovered'];
 	    $req->{noderange} = [$node];
+            if ($pbmc_node) {
+                $req->{pbmc_node} = [$pbmc_node];
+            }
 	    $req->{discoverymethod} = ['switch'];
 	    $doreq->($req); 
 	    %{$req}=();#Clear req structure, it's done..