Jason Rahm

Several months ago I wrote up the v10 formatting for internal and external datagroups: iRules Data Group Formatting Rules. In v11, however, there is a change to the format of the internal data group and the data group reference to external class files (the formatting in the external class file itself is unchanged). The formatting rules in v11 for data groups more closely resembles the tmsh commands necessary to build the class at the CLI (these command attributes are masked if you are using the GUI). I’ll follow the same format as the original write-up in showing the various data group types. The format is the same among internal data group types. If there is no value associated with the key, there is a curly bracket pair trailing the key on the same line. If there is an associated value with a key, the curly bracket opens the value, followed by a newline with the k... (more)

v11.1–External File Access from iRules via iFiles

New in BIG-IP version 11.1 are iFiles, a feature that allows users to load files through tmsh or the GUI onto the BIG-IP which can be referenced from iRules. This has an immediate use case of supplanting several of our codeshare entries for sorry and/or maintenance pages delivered directly from the BIG-IP instead of redirecting to a server to handle those requests. In this tech tip, I’ll cover the command options, the GUI configuration, and finally offer up a maintenance page iRule referencing iFiles. Planning the Maintenance Page When serving up html pages from an iRule in a vari... (more)

v11: RDP Access via BIG-IP APM–Part 1

I wrote an article several months back on auto-launching Remote Desktop sessions with APM.  With the introduction of BIG-IP APM v11, there is a new built-in capability to support a full webtop.  This means that server, desktop, or other resources can be placed on the webtop for users to select once logging in.  In this first example, I’ll set up a static internal resource for users to connect to after logging in. Create the Webtop After logging in to the BIG-IP, open up the Access Policy tab and select Webtops->Webtop List and then click Create (or you can hit the “+” circled to... (more)

iRules 101–#18–Revisiting the TCL Scan Command

I covered the Tcl scan command back in the iRules 101 – #16 – Parsing Strings with the TCL Scan Command, but this example (by Hoolio, who else?) was too good not to share with the community. The request involved parsing a log entry as efficiently as possible.  The log entry is as follows: Aug 05 08:01:13 ethos-re0 (FPC Slot 1, PIC Slot 1) TEST-{ss-nat-2}[FWNAT]: ASP_SFW_CREATE_ACCEPT_FLOW: proto 1 (ICMP ECHO REQUEST) application: icmp, xe- 0/0/0.21:10.1.1.1:33639 -> 192.168.22.254, creating forward or watch flow ; source address and identifier translate to 172.16.4.32:1135 The go... (more)

Announcing PyControl v2!

At long last, we’re happy to announce pycontrol, version 2! This version is a complete re-write of the original, with many improvements. Over the next several weeks keep an eye out for more samples posted to code share as well as tutorials, both in tech-tip and screen cast form.  Here are a few feature highlights: Attribute-driven for easy introspection of iControl methods. Optional single-file install. No longer requires root access. Just drop pycontrol.py somewhere you'll remember and add it to sys.path, or drop it onto sys.path itself. On-box WSDL or remote-fetch. This means ... (more)