To locate the hostnames and IP addresses of the ZENs for your IPSec VPN tunnels:
You can find the name of your cloud in the URL your admins use to log into the Zscaler service. For example, if an organization logs into admin.zscalertwo.net, then that organization's cloud name is zscalertwo. So, you would go to ips.zscalertwo.net. To learn more, see What is my cloud name?
For example, if you're located in London, scroll to the Europe section of the table to find lon3-vpn.zscalertwo.net (London) as your primary destination and amsterdam2-vpn.zscalertwo.net (Amsterdam) as your backup destination.