This 3 day course provides networking professionals 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.

Topics Covered

• 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

At the end of this course, the student will be able to:

• 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

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

Students must complete one of the following F5 prerequisites before attending this course:

? Administering BIG-IP instructor-led course -or-
? Configuring BIG-IP LTM instructor-led course -or-
? F5 Certified BIG-IP Administrator

The following free web-based courses, although optional, will be very helpful for any student with limited BIG-IP administration and configuration experience.

These courses are available at LearnF5 (https://www.f5.com/services/training):

? Getting Started with BIG-IP
? Getting Started with BIG-IP Local Traffic Manager (LTM)

The following general network technology knowledge and experience are recommended before attending any F5 Global Training Services instructor-led course:

? OSI model encapsulation
? Routing and switching
? Ethernet and ARP
? TCP/IP concepts
? IP addressing and subnetting
? NAT and private IP addressing
? Default gateway
? Network firewalls
? LAN vs. WAN

The following course-specific knowledge and experience is suggested before attending this course:

? HTTP protocol
? Any programming language

Chapter 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

Chapter 2: Getting Started with iRules

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

Chapter 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

Chapter 4: Developing and Troubleshooting iRules

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

Chapter 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) 

Chapter 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

Chapter 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)

Chapter 8: Processing the HTTP Payload

? Reviewing HTTP Headers and Commands
? Introducing iRule HTTP Header 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)

Chapter 9: Working with iFiles and Data Groups

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

Chapter 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)

Chapter 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

Other courses available:

F5N_BIG-LTM-CFG-3, Configuring BIG-IP LTM: Local Traffic Manager v.15.1
F5N_BIG-DNS-I, Configuring BIG-IP DNS (formerly GTM) v.15.1
F5N_BIG-AWF-CFG, Configuring F5 Advanced WAF (previously licensed as ASM) v15.1
F5N_BIG-EGW-APM, Configuring BIG-IP APM: Access Policy Manager v.15.1
F5N_BIG-AFM, Configuring BIG-IP AFM: Advanced Firewall Manager v.15.1
F5N_BIG-TRBL-INT2, Troubleshooting BIG-IP v.15.1