An Irule for Client Ssl Profile that Allows Unassigned TLS Extension Values (17516)
Hello Community, I have a requirement to allow enriched https header enrichment. The SSL negotiation (I'm doing ssl termination on F5) fails because the enriched header from client contains reserved tls extension values. (https://www.iana.org/assignments/tls-extensiontype-values/tls-extensiontype-values.xhtmltls-extensiontype-values-1). The Client Hello request in the SSL Handshake was captured and contained an Extensions list, which included a reserved TLS Extension value (17156), which the F5 isn't presenting in Server Hello. I need an irule that can allow that Extension to be added on the client ssl profile so the ssl handshake doesn't fail.IIS X-Forward-For ISAPI Filter
A recent customer issue came up where they were load balancing servers but we unable to get the true client address logged in their IIS logs. They had their servers fronted by a BIG-IP and when clients would make requests the address passed to the server was the internal address and not that of the client. This is a common issue with proxies and fortunately there is a standard for forwarding client information. It is the HTTP X-Forwarded-For header which is handled by most proxies. So, I set out to find an existing ISAPI filter to replace the c-ip (client ip) log value in IIS with the contents of the X-Forwarded-For header (if it exists). I was amazed to find that I couldn't find a single instance of any open source (or even commercial) filter that would do this. So, I dug out Visual Studio and whipped up a filter that does just that. It's very basic and contains no user configuration so all you need to do is plug it into your Web Applications list of ISAPI Filters within the IIS Administration and you're set to go. We've released the source under the iControl End User License Agreement (available in any iControl SDK download). You can download it here. If you find a way to optimize this filter, please let me know and I'll update the sources here. After 24-hours of posting, a customer already returned some performance testing on the filter indicating that it only effected the traffic by less than 1 percent. I'm sure there are ways to optimize the memory allocation in the filter to speed this up a bit more, but I'll leave that for the community to work on. Oh, and it should be noted that the X-Forwarded-For header isn't supported the same way across all proxy products so you'll want to make sure you test this out before using it. It is expecting the header to only contain an IP Address as it does a straight substitution on the value in the c-ip section of the log entry. Enjoy! -JoeF5 BIG-IP Multi-Site Dashboard
Code is community submitted, community supported, and recognized as ‘Use At Your Own Risk’. A comprehensive real-time monitoring dashboard for F5 BIG-IP Application Delivery Controllers featuring multi-site support, DNS hostname resolution, member state tracking, and advanced filtering capabilities. A 170KB modular JavaScript application runs entirely in your browser, served directly from the F5's high-speed operational dataplane. One or more sites operate as Dashboard Front-Ends serving the dashboard interface (HTML, JavaScript, CSS) via iFiles, while other sites operate as API Hosts providing pool data through optimized JSON-based dashboard API calls. This provides unified visibility across multiple sites from a single interface without requiring even a read-only account on any of the BIG-IPs, allowing you to switch between locations and see consistent pool, member, and health status data with almost no latency and very little overhead. Think of it as an extension of the F5 GUI: near real-time state tracking, DNS hostname resolution (if configured), advanced search/filtering, and the ability to see exactly what changed and when. It gives application teams and operations teams direct visibility into application pool state without needing to wait for answers from F5 engineers, eliminating the organizational bottleneck that slows down troubleshooting when every minute counts. https://github.com/hauptem/F5-Multisite-DashboardThree Things I've Learned Recently While Deploying F5 CIS on OpenShift
Not every CIS deployment issue is actually a CIS issue. This article walks through three lessons learned from recent OpenShift deployments where the real culprit turned out to be NetworkPolicies, image selection, and version management rather than the controller itself.
Recursive DNS resolution (DoT), allowing queries UDP/53 while BIG-IP forwards over TCP/853
How can I configure BIG-IP to perform recursive DNS resolution over DNS-over-TLS (DoT), allowing standard DNS clients to send queries over UDP/53 while BIG-IP forwards those queries securely over TCP/853? It is possible without a external resolver ?Advanced WAF IP Exceptions Manager
This solution introduces a dedicated Python-based GUI tool for managing IP whitelist exceptions in F5 BIG-IP Advanced WAF policies. The tool was developed to simplify a common operational workflow: searching WAF policies, adding IP or CIDR-based exceptions, checking whether an IP already exists across policies, deleting outdated exceptions, applying policy changes, and tracking actions through an activity log. The solution is especially useful in large environments where manual exception handling can create operational overhead, inconsistent policy configuration, or audit challenges. It demonstrates how focused automation can deliver practical value without requiring a large orchestration platform or full CI/CD pipeline.API Discovery and Enforcement with API Security Local Edition
API Security Local Edition is a self-hosted platform that discovers APIs from BIG-IP traffic insights, builds and maintains an inventory with risk scoring, and pushes enforcement back to BIG-IP. This article covers the architecture, the data flows between components, and the operator workflow from discovery to enforcement.
Introducing the F5 Application Study Tool (AST)
In the ever-evolving world of application delivery and security, gaining actionable insights into your infrastructure and applications has become more critical than ever. The Application Study Tool (AST) is designed to help technical teams and administrators leverage the power of open-source telemetry and visualization tools to enhance their monitoring, diagnostics, and analysis workflows.
