F5 Networks Developing iRules for BIG-IP

This course provides networking professionals with a functional understanding of iRules development. The course builds on the foundation of the Administering BIG-IP or Configuring LTM course, demonstrating how to logically plan and write iRules to help monitor and manage common tasks involved with processing traffic on the BIG-IP system. Extensive course labs consist of writing, applying and evaluating the effect of iRules on local traffic. This hands-on course includes lectures, labs, and discussions.

Course Objectives | Developing iRules for BIG-IP

• Describe the role of iRules in customizing application delivery on a BIG-IP system
• Describe best practices for using iRules
• Define event context, and differentiate between client-side and server-side contexts, request and response contexts, and local and remote contexts
• Trigger an iRule for both client-side and server-side request and response events
• Assign multiple iRules to a virtual server and control the order in which duplicate events trigger
• Describe and use a testing methodology for iRule development and troubleshooting
• Use local variables, static variables, lists, arrays, the session table, and data groups to store information needed for iRule execution
• Write iRules that are optimized for runtime and administrative efficiency
• Use control structures to conditionally branch or loop within an iRule
• Log from an iRule using Linux syslog-ng or TMOS high-speed logging (HSL)
• Incorporate coding best practices during iRule development
• Use analyzer tools to capture and view traffic flow on both client-side and server-side contexts
• Collect and use timing statistics to measure iRule runtime efficiency
• Write iRules to help mitigate and defend from some common HTTP attacks
• Differentiate between decimal, octal, hexadecimal, floating-point, and exponential notation
• Parse and manipulate strings using Tcl commands and iRule functions
• Write iRules to access and manipulate HTTP header information
• Write iRules to collect customized statistics
• Implement universal persistence via an iRule
• Modify payload content using an iRule with a stream profile

Course Topics | Developing iRules for BIG-IP

• Setting up the BIG-IP system
• Getting started with iRules
• Leveraging DevCentral resources for iRule development
• Exploring iRule elements, including events, functions, commands, variables, and operators
• Using control structures for conditional branching and looping
• Mastering whitespace, grouping, and special symbols
• Measuring iRule efficiency using timing statistics
• Logging from an iRule using syslog-ng and high-speed logging (HSL)
• Optimizing iRules execution, including implementing efficiency best practices
• Modularizing iRules for administrative efficiency, including using procedures
• Securing web applications with iRules, including preventing common HTTP attacks, securing HTTP headers and cookies, and implementing HTTP strict transport security (HSTS)
• Working with strings, including using Tcl parsing commands and iRules parsing functions
• Accessing and manipulating HTTP traffic, including applying selective HTTP compression
• Working with iFiles and data groups
• Using iRules with universal persistence and stream profiles
• Gathering statistics using STATS and ISTATS
• Incorporating advanced variables, including arrays, static variables, and the session table

Lesson 1 : Setting Up the BIG-IP System

• Introducing the BIG-IP System 
• Initially Setting Up the BIG-IP System 
• Archiving the BIG-IP System Configuration 
• Leveraging F5 Support Resources and Tools

Lesson 2 : Getting Started with iRules

• Customizing Application Delivery with iRules 
• Triggering an iRule 
• Leveraging the DevCentral Ecosystem 
• Creating and Deploying iRules

Lesson 3 : Exploring iRule Elements

• Introducing iRule Constructs 
• Understanding iRule Events and Event Context 
• Working with iRule Commands 
• Logging from an iRule Using SYSLOG-NG (LOG Command) 
• Working with User-Defined Variables 
• Working with Operators and Data Types 
• Working with Conditional Control Structures (IF and SWITCH) 
• Incorporating Best Practices in iRules

Lesson 4 : Developing and Troubleshooting iRules

• Mastering Whitespace and Special Symbols 
• Grouping Strings 
• Developing and Troubleshooting Tips 
• Using Fiddler to Test and Troubleshoot iRules

Lesson 5 : Optimizing iRule Execution

• Understanding the Need for Efficiency 
• Measure iRule Runtime Efficiency Using Timing Statistics 
• Modularizing iRules for Administrative Efficiency 
• Using Procedures to Modularize Code 
• Optimizing Logging 
• Using High-Speed Logging Commands in an iRule 
• Implementing Other Efficiencies 
• Using Looping Control Structures (WHILE, FOR, FOREACH Commands)

Lesson 6 : Securing Web Applications with iRules

• Integrating iRules into Web Application Defense 
• Mitigating HTTP Version Attacks 
• Mitigating Path Traversal Attacks 
• Using iRules to Defends Against Cross-Site Request Forgery (CSRF) 
• Mitigating HTTP Method Vulnerabilities 
• Securing HTTP Cookies with iRules 
• Adding HTTP Security Headers 
• Removing Undesirable HTTP Headers

Lesson 7 : Working with Numbers and Strings

• Understanding Number Forms and Notation 
• Working with Strings (STRING and SCAN Commands) 
• Combining Strings (Adjacent Variables, CONCAT and APPEND Commands) 
• Using iRule String Parsing Functions (FINDSTR, GETFIELD, and SUBSTR Commands)

Lesson 8 : Processing the HTTP Payload

• Reviewing HTTP Headers and Commands 
• Accessing and Manipulating HTTP Headers (HTTP::header Commands) 
• Other HTTP commands (HTTP::host, HTTP::status, HTTP::is_keepalive, HTTP::method, HTTP::version,
• HTTP::redirect, HTTP::respond, HTTP::uri) 
• Parsing the HTTP URI (URI::path, URI::basename, URI::query) 
• Parsing Cookies with HTTP::cookie 
• Selectively Compressing HTTP Data (COMPRESS Command

Lesson 9 : Working with iFiles and Data Groups

• Working with iFiles 
• Introducing Data Groups 
• Working with Old Format Data Groups (MATCHCLASS, FINDCLASS) 
• Working with New Format Data Groups (CLASS MATCH, CLASS SEARCH)

Lesson 10 : Using iRules with Universal Persistence, Stream, and Statistics Profiles

• Implementing Universal Persistence (PERSIST UIE Command) 
• Working with the Stream Profile (STREAM Command) 
• Collecting Statistics Using a Statistics Profile (STATS Command) 
• Collecting Statistics Using iStats (ISTATS Command)

Lesson 11 : Incorporating Advanced Variables

• Reviewing the Local Variable Namespace 
• Working with Arrays (ARRAY Command) 
• Using Static and Global Variables 
• Using the Session Table (TABLE Command) 
• Processing Session Table Subtables 
• Counting “Things” Using the Session Table

Administering BIG-IP or Configuring BIG-IP LTM: Local Traffic Manager or hold the F5 Certified BIG-IP Administrator certification

This course is intended for system administrators, network administrators and application developers responsible for the customization of traffic flow through a BIG-IP system.