diff --git a/definitions/ext-endpoint/definition.yml b/definitions/ext-endpoint/definition.yml
new file mode 100644
index 000000000..821b9e185
--- /dev/null
+++ b/definitions/ext-endpoint/definition.yml
@@ -0,0 +1,7 @@
+# EXT-ENDPOINT represents a network endpoint (e.g. an IP:PORT tuple).
+domain: EXT
+type: ENDPOINT
+
+configuration:
+  entityExpirationTime: FOUR_HOURS
+  alertable: true