diff --git a/perl-xCAT/xCAT/Utils.pm b/perl-xCAT/xCAT/Utils.pm
index 832064099..7ed63578a 100644
--- a/perl-xCAT/xCAT/Utils.pm
+++ b/perl-xCAT/xCAT/Utils.pm
@@ -3623,7 +3623,15 @@ sub get_ServiceNode
 
     if ($request eq "MN")
     {
-       $snattribute = "servicenode";
+       # When run mkhwconn/lshwconn/rmhwconn with -T fnm for CNM, it will send the 
+       # command from the MN to CEC/Frame direclty, not through the service node if specified.
+       # The $onlymaster is set in preprocess_request() in PPC.pm
+       # It will not affect the others
+       if(  defined($onlymaster) && $onlymaster == 1) {
+            $snattribute = "xcatmaster";
+	    } else {
+	        $snattribute = "servicenode";
+	    }
 
     }
     else    # Node