In a tiered implementation, Redistribution Servers at the highest tier must access the Internet to retrieve signature and content updates from etrustdownloads.ca.com.
The CA Content Update Servers are load balanced and optimized to switch to an available server as needed; therefore, CA does not support downloading updates with a fixed IP address for the CA Content Update Server as there is no guarantee that any specific IP address will be available at any given time.
etrustdownloads.ca.com can be used with either http or https. Some organizations prefer the latter to reduce the risk of "man in the middle" attacks.