diff --git a/README.md b/README.md
index 4f908ac..9ebb35b 100644
--- a/README.md
+++ b/README.md
@@ -3,3 +3,11 @@
 Raspberrymatic Plugin
 
 https://github.com/thkl/hap-homematic/raw/master/addon_installer/hap-raspb-0.0.1.tar.gz
+
+
+Used Ports : 
+9875 -> Config WebUI
+9875 -> RPC Event Server
+9876..n HAP Instance 0 .. n
+
+make sure your CCU firewall does not block these ports
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