HP Advance Technology - Intelligent Resilient Framework (IRF)

Introduction: 
The fundamental nature of networking is changing, especially in enterprise data centers. With new, integrated applications deployed against large scale, highly virtualized server farms, server-to-servercenter communications are demanding a completely new level of intra-data-center performance. Traditional three-tier networks— designed to support data-center-in/data-center-out traffic and built using legacy, poor-performing redundancy protocols—can’t deliver the server-to-server capacity required for these types of workloads.

Purpose-built HP networking solutions, system architecture, and technology are streamlining the design of next-generation data centers and campus networks to ensure the superior resiliency, performance, and agility that enterprise networks now require. One HP innovation is Intelligent Resilient Framework (IRF), a technology that far outstrips ordinary protocols designed to improve the performance of network
switches.

What is IRF ?
Intelligent Resilient Framework (IRF) is a software virtualization technology developed by H3C. IRF combines multiple physical devices into a logical device. IRF 2.0 is a common virtualization technology that combines multiple devices into a virtual device. The virtual device has higher expandability, reliability and performance. IRF 2.0 has been applied on high-end, middle-range and low-end series switches.
 
How it works:
IRF technology extends network control over multiple active switches. Management of a group of IRF enabled switches is consolidated around a single management IP address, which vastly simplifies network configuration and operations. You can combine as many as nine HP A-series switches to create an ultra-resilient virtual switching fabric
comprising hundreds or even thousands of 1-GbE or 10-GbE switch ports.

One IRF member operates as the primary system switch, maintaining the control plane and updating forwarding and routing tables for the other devices. If the primary switch fails, IRF instantly selects a new primary, preventing service interruption and helping to
deliver network, application, and business continuity for business-critical applications.
Within the IRF domain, network control protocols operate as a cohesive whole to streamline processing, improve performance, and simplify network operation.

So routing protocols calculate routes based on the single logical domain rather than the multiple switches it represents. Moreover, edge or aggregation switches that are dual homed to IRF-enabled core or data center switches “see” the associated switches
as a single entity, eliminating the need for slow convergence technologies such as STP. And operators have fewer layers to worry about, as well as fewer devices, interfaces, links, and protocols to configure and manage.

Virtualization

An IRF that combines box-type devices operates like a chassis-type distributed device. The master in the IRF operates as the active main board (AMB) of the IRF, and the slaves operate as the standby main boards (SMBs) (also operate as interface boards), as shown in Figure 1-1.

Figure 1-1 Box-type device virtualization schematic diagram

An IRF that combines chassis-type distributed devices also operates like a chassis-type distributed device. It has more SMBs and interface boards than an IRF that combines box-type devices. The AMB of the master is the AMB of the IRF, and the SMBs of the master, the AMBs and SMBs of the slaves are the SMBs (also operate as interface boards) of the IRF, as shown in Figure 1-2.

Figure 1-2 Chassis-type distributed device virtualization schematic diagram

The virtual device can be considered as a single entity. Users can log in to any member device in the IRF through the console port or telnet to manage and configure the entire IRF. The functions of the virtual device can run as if on a single distributed device.

Advantage of IRF:

Employing IRF offers a number of benefits over conventional networking. You will find advantages in three major areas: simplicity, performance, and resiliency.

Advantages in simplicity
• Design and operational simplification: 

With IRF, no longer must you laboriously connect to, configure, and manage switches individually. You perform a configuration on the primary switch, and that configuration is distributed to all associated switches automatically, considerably simplifying network setup, operation, and maintenance. And while all HP A-series switches can be provisioned via the command line, adding HP Intelligent Management Center (IMC) makes management even easier. IMC lets you see and control the entire network from a single console by consolidating management of multiple, discrete devices into a single, easy-to-manage, virtual switch that operates at every layer of the network.

• Flatter topology: 

IRF makes possible a simplified, higher performing, more resilient, and flatter network design. In fact thanks to IRF and HP A-series switches, enterprise networks can be designed with fewer devices and fewer networking layers—a big improvement over the low performance, high cost, and crippling latency of conventional multi-tier legacy solutions, which often rely on a variety of different operating systems and complex resiliency protocols.

Advantages in performance
• Higher efficiency:

IRF’s loop-free, non-blocking architecture keeps all links active, enabling highly efficient, high-bandwidth connectivity throughout the switching plane. Simply stated, you get all the bandwidth you are paying for.
• Scalable performance: 

IRF and Link Aggregation Control Protocol (LACP) used together can further
boost performance by bundling several parallel links between switches and servers, allowing scalable “on-demand” performance and capacity to support critical business applications.
• Faster failover: 

Should a network failure occur, IRF can deliver rapid recovery and network
reconvergence in under 50 milliseconds—much faster than the several seconds required for STP.
 

Advantages in resiliency
• Distributed high availability and resiliency: 

For high availability, the IRF fabric can be configured for full N+1 redundancy, while mission-critical virtualization capabilities such as live migration and application mobility are available across the IRF domain and extend across the Layer 2 WAN infrastructure.
• Geographic resiliency: 

Within an IRF domain, the geographic location of switches does not matter. Switches can be extended horizontally, and they continue to function as a single logical unit whether they are installed locally, distributed regionally, or even situated at distant sites. Moreover, employing IRF can enhance disaster recovery by linking installations up to 70 kilometers apart and giving them the same fast failover as if they were sitting
side by side within the data center. Such location independence is extremely important to support the global on-demand application access and dynamic traffic flows of today’s technology-oriented businesses.
• In-Service-Software-Upgrade: 

IRF delivers a network-based In-Service-Software-Upgrade (ISSU) capability that allows an individual IRF-enabled switch to be taken offline for servicing or software upgrades without affecting traffic going to other switches in the IRF domain.