---
title: "SSO and SimpleSAMLphp Configuration for CDNs"
date: "2022-02-24T14:54:59+00:00"
summary:
image:
type: "article"
url: "/acquia-cloud-platform/help/93151-sso-and-simplesamlphp-configuration-cdns"
id: "e1a2a82f-971c-4518-adcd-37852c3d67e3"
---

Please note: The below example relates to the Acquia Cloud Edge CDN. For details on troubleshooting redirect loops for Cloud Platform CDN, please see our [Cloud Platform CDN documentation](/node/56194)

A redirect loop can occur when a user tries to authenticate with SSO/SAML but because of the presence of a cache or CDN which is not set to bypass the cache on the presence of the SAML cookie(s).  SimpleSAMLPHP uses a cookie starting with 'SimpleSAML', so bypasing the cache for 'SimpleSAML.\*' should avoid any issues. See below for an example Page Rule

![Cache settings for example.com include browser and edge TTL, cache level, and cookie bypass, with apps disabled.](https://acquia.widen.net/content/2d2f7bc1-9059-407e-9367-d8197023736b/web/ka06g000001twHv00N6g00000VCdgi0EM6g000002WVGp.png)

  
Redirect loops can also be caused by a redirect switching from http to https, refer to the [SimpleSAMLphp debugging documentation](https://simplesamlphp.org/docs/stable/simplesamlphp-nostate) as well as the [Troubleshooting SimpleSAML article.](/node/92471)