diff --git a/etc/dhcp_agent.ini b/etc/dhcp_agent.ini
index e38bae22b0..90c1200a86 100644
--- a/etc/dhcp_agent.ini
+++ b/etc/dhcp_agent.ini
@@ -64,3 +64,6 @@
 
 # Location to DHCP lease relay UNIX domain socket
 # dhcp_lease_relay_socket = $state_path/dhcp/lease_relay
+
+# Location of Metadata Proxy UNIX domain socket
+# metadata_proxy_socket = $state_path/metadata_proxy
diff --git a/etc/l3_agent.ini b/etc/l3_agent.ini
index 77e5d15cb2..3815071cf2 100644
--- a/etc/l3_agent.ini
+++ b/etc/l3_agent.ini
@@ -60,3 +60,6 @@
 # enable_metadata_proxy, which is true by default, can be set to False
 # if the Nova metadata server is not available
 # enable_metadata_proxy = True
+
+# Location of Metadata Proxy UNIX domain socket
+# metadata_proxy_socket = $state_path/metadata_proxy
diff --git a/etc/metadata_agent.ini b/etc/metadata_agent.ini
index 12c04587ba..1be698be74 100644
--- a/etc/metadata_agent.ini
+++ b/etc/metadata_agent.ini
@@ -23,3 +23,6 @@ admin_password = %SERVICE_PASSWORD%
 # but it must match here and in the configuration used by the Nova Metadata
 # Server. NOTE: Nova uses a different key: neutron_metadata_proxy_shared_secret
 # metadata_proxy_shared_secret =
+
+# Location of Metadata Proxy UNIX domain socket
+# metadata_proxy_socket = $state_path/metadata_proxy