What are the IP ranges for TeamCity Cloud servers?

The following IP ranges are used for the TeamCity Cloud servers:

54.155.204.237/32
79.125.74.147/32

For whitelisting purposes, outbound connections from a TeamCity Cloud server will originate from one of the above IP addresses.

The following IP ranges are used for the JetBrains hosted build agents:

52.49.162.42/32
52.214.29.36/32 

For whitelisting purposes, outbound connections from a JetBrains hosted build agent will originate from one of the above IP addresses.

To lookup these IP ranges programmatically, you can use this JSON-based endpoint:

https://meta.teamcity.com/cloud-public-metadata/tcc-addresses-eu-west-1.json

TeamCity Cloud domain names (*.teamcity.com) have a dynamic IP address associated with them via AWS CloudFront – these IP addresses should not be used for whitelisting purposes. If you wish to whitelist connections originating from your own internal network to a TeamCity Cloud server, you should whitelist by hostname rather than IP address.