Converting iRules Guides

HowTo guides for converting iRules to Netscaler

• Blocking Requests from Range of IP’s
  Most of the client requests come through a proxy and the original client IP is in the HTTP Headers and there is requirement to take specific actions based on the client ip which is present in the header.

• Blocking Specific SMTP Users
  Customer needs the ability to reset specific SMTP users.

• Authenticating Client Using HTTP Cookie
  Performing Client authentication and validation through HTTP Cookies
• Dynamic Connection Check
  Runtime check and traffic redirection based on outstanding connections at vserver
• Google reCAPTCHA Challenge
  Including Google CAPTCHA challenge and validation in ADC auth flow
  
• Header Insertion for Content Security
  Defining and inserting required headers in response for content security
• Load Balancing during Maintenance Window
  How to perform efficient load balancing during maintenance timeframe
• Pseudo-random hex character generator
  Generation of pseudo-random hex character and using it in the policy flow
• Remove X-* Headers from Response
  Handing multiple X-* headers inserted by proxies on request path
• Remove Whitespace from HTTP Response Payload
  Handing of unnecessary whitespace while doing content modification
• Rewrite HTTP Redirect Port
  Manipulating the Location header to remove specific port assignment
• Rewrite in Stream mode
  Content rewrite in stream mode operation for better efficiency
• IP/SUBNET Based Routing for Email Client
  Routing decision based on incoming request destination IP and Subnet
• TFTP load balancing
  Load balancing for the TFTP traffic flow
• Validate String Characters in Cookie
  Validating the Cookie value to ensure it matches the App policies
• X-Forwarded-For Header Insert
  Checking for the header and inserting one if not found with respective value
• Akamai True-Client-IP Header Persistence
  Persistence based on Akamai's True-Client-IP header for ensuring actual Client IP is seen.
• Alternate Solution to Sideband connection
  Sideband functionality in F5’s solution provides an ability to call an external resource before a load balancing decision has been made.
• Cache Control Behavior
  Controlling and customizing Caching behavior working with end client.
• Categorize SSL traffic by protocol version
  Provides visibility into incoming SSL connections with respect to SSL protocol version.
• Client Persistence based on Response
  Taking client persistency decision based on the HTTP response coming from backend.
• Computing HMAC
  HMAC computation on data flowing through for security reasons.
• Conditional Redirects based on Hostname
  HTTP to HTTPS redirect with exceptions based on Hostname check.
• CORS Implementation
  Cross origin resource sharing is required when you are dealing with multiple domains and all of them need to be able to make calls to specific sub-domains or the to the API layer.
• Disable HTTP Processing For Selective HTTP Methods
  Disable HTTP processing and specific functions for unknown methods.
• Do Not Cache POST Request
  HTTP Post requests by definition should not be marked cacheable as they update state on server end.
• Handling Accept-Encoding Header
  Defining Compression behavior in between HTTP endpoints.
  
• HTML Comment Scrubber
  Removing comments from HTML payload.
  
• HTTP Cookie Security
  Securing HTTP cookie value while it passes through untrusted networks.
• HTTP redirect based on Client Region
  HTTP redirect based on Client location taken from source IP address.
• HTTP Request Cloning
  Ability to clone the HTTP incoming request and send it to another specified destination.
• Location Header Rewrite with non-standard Port
  Many times while dealing with redirects, you many need to deal with specific non-standard Ports as well.
• Log HTTP Headers
  Logging of HTTP headers for enhanced log collection and troubleshooting use cases.
• Issuer Validation from Client Certificate
  Validating Issuer of the Client certificate received as part of SSL handshake.
• Mitigate Microsoft vulnerability for Backend
  Many data centers run with Microsoft servers. Some server vulnerabilities can be mitigated on the load balancer by parsing them for specific patterns while it processes requests.
• Parse and Log Username from HTTP requests
  Parse and log the username from the Authorization header in HTTP Requests.
• Proxy Chaining & URL Rewriting
  Proxy chaining operation while rewriting the URL or a part of it.
• Proxy Chaining via Categorization
  Content categorization and proxy decision making.
• Protection with Basic Authentication
  How to use Basic Authentication for end users without getting into complex setup and requirements.
• Proxy Protocol Receiver
  Delete PROXY protocol header from TCP payload.
• Ratio Based Load Balancing
  Ratio based LB allows you to use pseudo random number generation, in run time take decisions like sending part of the traffic to one pool versus another.
• Redirect on Weak Encryption
  Using cipher strength, protocol version and key length to decide overall security provided by SSL layer.
• Redirect Location header validator
  Location header interception for any redirects which are to a domain that is not part of the whitelist.
• Random Letter Generator
  Generating a string of pseudo-random letters.
• Redirect HTTP requests on a SSL vserver
  This configuration allows you to handle the HTTP requests coming for a SSL endpoint.
• Rewrite HTTP Redirect response
  Modify the HTTP redirect response going out of NetScaler.
  
• Select the Backend based on Query
  Take load balancing decision based on HTTP query parameter which also simulates pseudo persistence.
• SSL 3.0 Client Tracker
  SSLv3 is known to be weak and vulnerable thus ability to track the SSLv3 transaction is important for the administrators.
  
• Stream Rewrite
  Rewrite the HTTP request and response stream for same communication channel such that you can do 2-way update.
• URL Shortener
  Reducing the overall length of the URL for better efficiency and security.
• XFF Header Based Persistence
  Defining client persistence based on X-Forwarded-For HTTP header.

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