> For the complete documentation index, see [llms.txt](https://docs.corppass.gov.sg/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.corppass.gov.sg/what-you-need-to-know-before-onboarding-a-digital-service-in-corppass/important-things-to-note/whitelisting-corppass-ip-addresses-for-outgoing-traffic.md).

# Whitelisting Corppass IP Addresses for Outgoing Traffic

## **Why can't I whitelist Corppass IP addresses for outgoing traffic?**

For enterprise networks or networks with restricted traffic, it's common for system administrators to configure a whitelist of outgoing traffic. However, Corppass advises against whitelisting IP addresses and recommends whitelisting by domain instead. Here's why:

* **Corppass operates on AWS**: Corppass uses CloudFront, which relies on a large and dynamic pool of IP addresses to ensure high availability of services. This list of IP addresses can change periodically.
* **IP addresses may change**: If you whitelist Corppass endpoints by IP address, there's no guarantee that these addresses will remain static. Changes in IP addresses can cause disruptions, preventing your e-service from accessing Corppass.

Therefore, whitelisting by domain is always the preferred and more reliable method.

***

### **Can I still use IP address whitelisting for Corppass?**

If you must use IP address whitelisting, refer to the following AWS CloudFront resources:

* [AWS CloudFront Edge Server Locations](https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/LocationsOfEdgeServers.html)
* [List of CloudFront IP Addresses](https://d7uri8nf7uskq.cloudfront.net/tools/list-cloudfront-ips)

However, please note that using these resources may still result in disruptions due to changes in IP addresses over time.