F5 iRules Fundamentals

Learn the if control structure in iRules, using if, else, and else if to route actions by uri conditions and support basic load balancing scenarios.

Learn the switch control structure in iRules, using exact matches, defaults, and dash glob patterns to route http uri to appropriate nodes within a pool.

Explore iRule tcp/ip events across layers—the tcp/ip layer, the load balancing layer, and the http layer—and learn how client accepted, http request, server selected, and server connected events guide decisions.

Master iRule tcp/ip events in part 2, enabling snat auto map with the self ip and routing to pool members, while matching client ip to a subnet guides gateway behavior.

Explore iRule lb events, including selected and failed events, with commands to inspect the chosen pool member, snat/self-nat behavior, reselect, and mode-based load balancing.

Review the http protocol basics, including request structure, methods (get, post), url and uri breakdown, headers and cookies, and common response codes like 200, 404, and 500.

Explore iRule http events by extracting and modifying http request and response data, including host, uri, path, and query, and working with http headers, redirects, and status codes.

Learn loop structures in iRules, including for, while, and for each, to iterate http headers, access names and values, remove headers, and return http response when the pool is offline.

Apply iRule traffic redirection to route http requests by active pool members using pool, node, and virtual server commands. Redirects target pools, nodes, or virtual servers; drop traffic by geography.

Explore iRules priority and the order of execution on a virtual server, including how lower priorities decide which rule runs first and how to insert the client IP header.

Learn how iRules data groups simplify multi-rule subnet matching and application routing by centralizing IP address lists and string values, enabling whitelist and blacklist configurations and dynamic pool selection.