diff --git a/xCAT-server/lib/xcat/plugins/dhcp.pm b/xCAT-server/lib/xcat/plugins/dhcp.pm
index 8a5d659ef..d6e24d6e9 100644
--- a/xCAT-server/lib/xcat/plugins/dhcp.pm
+++ b/xCAT-server/lib/xcat/plugins/dhcp.pm
@@ -927,6 +927,7 @@ sub process_request
     }
 
     @dhcpconf = ();
+    @dhcp6conf = ();
     
    my $dhcplockfd;
    open($dhcplockfd,">","/tmp/xcat/dhcplock");