Materials from the Agility 2016 class. Class intro:
While many in the industry know of BIG-IPs Global Service Load-Balancing (GSLB) capability, fewer know that BIG-IP can also be used as an iterating cache server, as well as an authoritative DNS resolver. BIG-IP provides high performance and increased security, particularly when AFM is provisioned and configured along with DNS Services. As with other BIG-IP functions, iRules can be used to customize DNS operation and to provide specialized DNS security.
Moreover, while the standard full-proxy architecture of the BIG-IP works very well for many protocols, the paradigm is not optimal for message-based protocols, particularly those that are part of peer architectures, rather than client/server architectures. In 11.5, the Message Routing Framework was introduced to BIG-IP. This framework handles protocol-specific peer session maintenance, and message-based routing, rather than flow based traffic forwarding. Over time, SIP and Diameter have been migrated to this framework. Again, iRules can be quite valuable for augmenting MRF traffic handling.
This class is not intended to teach you the fundamentals of the BIG-IP platform, of DNS, of SIP, or MRF. It is not even intended to provide a progressive approach to iRules instruction. BIG-IPs are most often maintained by Network, Systems and Security Engineers, whose primary job is not software development. Given this, a pragmatic approach for creating an iRule is to find an example that does something similar, and customize it for the specific need. This class provides a series of iRule recipes which solve real-world problems. They are provided with the hope that they can serve as templates for solving a much wider range of issues.
Released 01.00.00 on 19-08-2016