If you want to configure rules for Saas services on the PaloAlto Firewall, you can do this using the App ID for the particular service, or you can use the IP addresses, Domains or URLs of the service in the policy.
However, since Saas services typically do not use only one IP address, domain or URL, and since these can change dynamically, it requires a dynamic list that is constantly updated automatically.
PaloAlto offers this service as «EDL hosting service». External Dynamic Lists (EDL) are dynamic lists that can contain a list of IP addresses, domains or URLs. These lists are periodically queried by the firewall and updated accordingly. These EDL lists can then be used in various policies. Due to the automatic update of the lists, they are always up to date. There is also no need to commit the configuration if the list changes.«PaloAlto EDL Hosting Service» weiterlesen