The Always Available Network

arubhat · ‎08-06-2019

High Availability is table stakes, there is no denying this. Enterprises lose $300,000 for every hour their networks are down¹. A large majority of today’s enterprise customers demand >99.99% uptime on their networks, a number that translates to less than an hour of downtime, annually! Add in hospitals and Emergency Responders to the mix, and Highly Available networks are not only about productivity or preventing financial losses, they are about saving lives.

Cisco Catalyst 9600 Series switches, successor to the venerable Catalyst 6000, are all about high availability, with redundancy baked into every layer: from the network protocols and features, to the modular Cisco IOS XE operating system, down to redundant and field replaceable hardware components.

Cisco Catalyst 9600

Always On Network

With the release of the Cisco IOS XE 16.12.1, Catalyst 9600 Series switches now support StackWise Virtual, bringing virtual chassis redundancy to the core of your network. Using StackWise Virtual, your effective bandwidth can be doubled, while providing multiple paths to all downstream and upstream devices and services, without the need for complex protocols or traffic engineering. Catalyst 9400 and Catalyst 9500 Series switches also support StackWise Virtual, providing consistent availability at every layer of the network topology.

Modular Catalyst 9600 Series switches can be configured with fully-synced dual supervisors in a chassis, offering less than 5ms failover downtime. Dual supervisors also allow hitless software updates without any downtime using ISSU (in-service software upgrade) techniques.

In the coming quarters, there is a strong and feature rich roadmap on the Catalyst 9600, with plans to support Quad Supervisor redundancy with StackWise Virtual, bringing together the most failure resistant Catalyst 9000 switch yet.

Resilient OS

Hot Patch SMUs

Much has been said about the open, modular, flexible and programmable Cisco IOS XE operating system. The modularity of the OS enables zero downtime hot-patching using Software Maintenance Updates (SMUs).

An SMU is an independent, self-sufficient subset of the IOS XE software package. SMUs are fully supported by Cisco TAC and can be “hot patched” (installed without restarting a system) or “cold patched” when deeper changes necessitate a restart. These can address issues ranging from recently discovered security incidents, to bug-fixes and enhancements – all with zero downtime. Using the Cisco DNA Center to deploy hot patches takes deployment manageability all the way to 11.

Total Redundancy

Redundancy all the way

For power resiliency, Catalyst 9600 Series switches support up to 4 power supplies capable of running both AC and DC simultaneously, in order to connect both to the grid as well as battery-backed power for highly critical operations. Power supplies can be run in N+1 mode, tolerating the loss of one power supply unit without interrupting operation. Field replacable power supply units can be installed while in operation, assuming the remaining power supplies provide enough juice for the running system.

The redundancy story doesn’t stop there. Redundancy also extends to the 9-fan N+1 reversible fan tray, which can be field upgraded even while in operation. Once the fan tray is removed, the user has a full two-minute window in which the fan tray can be replaced. The fan tray can be installed in the front or rear, for easier installation and service.

The Catalyst 9600 Series builds on the richness of the Catalyst 6000 legacy, along with all of the new HA innovations of the Catalyst 9000 family, and the robustness of the Cisco IOS XE operating system to bring your intent-based network the highly available core it deserves!

References:

Gartner report on network downtime:

https://blogs.gartner.com/andrew-lerner/2014/07/16/the-cost-of-downtime/