Update README.md

aks/README.md

@@ -90,6 +90,9 @@ Currently AKS on Azure China could be created by [Azure portal](https://portal.a
 
 Since some container registries like `docker.io`, `gcr.io` are not accessible or very slow in China, we have set up container registry proxy servers for Azure China VMs:
 > First docker pull of new image will be still slow, and then image would be cached, would be much faster in the next docker pull action.
+
+> **Note**:
+currently *.azk8s.cn could only be accessed by Azure China IP, we don't provide public outside access any more. If you have such requirement to whitelist your IP, please contact akscn@microsoft.com, provide your IP address, we will decide whether to whitelist your IP per your reasonable requirement, thanks for understanding.
 
 | global | proxy in China | format | example |
 | ---- | ---- | ---- | ---- |