diff --git a/etc/dhcp_agent.ini b/etc/dhcp_agent.ini
index 583f136e6..9836d3500 100644
--- a/etc/dhcp_agent.ini
+++ b/etc/dhcp_agent.ini
@@ -36,9 +36,9 @@
 
 # The DHCP server can assist with providing metadata support on isolated
 # networks. Setting this value to True will cause the DHCP server to append
-# specific host routes to the DHCP request.  The metadata service will only
-# be activated when the subnet gateway_ip is None.  The guest instance must
-# be configured to request host routes via DHCP (Option 121).
+# specific host routes to the DHCP request. The metadata service will only
+# be activated when the subnet does not contain any router port. The guest
+# instance must be configured to request host routes via DHCP (Option 121).
 # enable_isolated_metadata = False
 
 # Allows for serving metadata requests coming from a dedicated metadata