Web Agent Guides › Web Agent Configuration Guide › Protecting Web Applications › Header Variables and End-User IP Address Validation › How Custom Headers Validate IP Addresses

How Custom Headers Validate IP Addresses

The Web Agent can now use a custom HTTP header to determine a user's IP address instead of using the REMOTE_ADDR variable. If a proxy or other device sets a custom client IP header and the Web Agent is configured to look for that header on an incoming request, the Agent uses that header as the source of the client IP information.

In addition to configuring a custom header, you can set up a list of proxy IP addresses. If the REMOTE_ADDR matches an address in the proxy list, the Web Agent retrieves the user's IP address from the custom header. Otherwise, the user's IP address is obtained from the REMOTE_ADDR.

After the Web Agent resolves the requestor's IP address, the address is stored and used for request processing. If an address cannot be resolved, the IP address is set to unknown.

The Web Agent logs where the client IP address was resolved from to facilitate any debugging that may be necessary.