diff --git a/perl-xCAT/xCAT/Schema.pm b/perl-xCAT/xCAT/Schema.pm
index e53aa4eb0..bff4ec7ae 100644
--- a/perl-xCAT/xCAT/Schema.pm
+++ b/perl-xCAT/xCAT/Schema.pm
@@ -1213,7 +1213,7 @@ routes => {
 	routename => 'Name used to identify this route.',
 	net => 'The network address.',
 	mask => 'The network mask.',
-	ifname => '(optional) The interface name of the management node facing the gateway.',
+	ifname => 'The interface name that facing the gateway. It is optional for IPv4 routes, but it is required for IPv6 routes.',
 	gateway => 'The gateway that routes the ip traffic from the mn to the nodes. It is usually a service node.',
 	comments => 'Any user-written notes.',
 	disable => "Set to 'yes' or '1' to comment out this row.",