diff --git a/readme.md b/readme.md
index b2e8c82c..742e0fec 100644
--- a/readme.md
+++ b/readme.md
@@ -137,6 +137,7 @@ No and it will not be added. Please use a dedicated domain for Nextcloud and set
 The recommended way is to set up a local dns-server like a pi-hole and set up a custom dns-record for that domain that points to the internal ip-adddress of your server that runs Nextcloud AIO. Below are some guides:
 - https://www.howtogeek.com/devops/how-to-run-your-own-dns-server-on-your-local-network/
 - https://howchoo.com/pi/pi-hole-setup together with https://docs.callitkarma.me/posts/PiHole-Local-DNS/
+- https://dockerlabs.collabnix.com/intermediate/networking/Configuring_DNS.html
 
 ### How to skip the domain validation?
 If you are completely sure that you've configured everything correctly and are not able to pass the domain validation, you may skip the domain validation by adding `-e SKIP_DOMAIN_VALIDATION=true` to the docker run command of the mastercontainer.