Designing a loop-free, redundant network

by | Aug 16, 2017 | Infrastructure | 0 comments

IT departments have many responsibilities these days, but the main jobs can be boiled down to making sure your users have the technology, access, and speed that they need to complete their job. The quality of your network plays an out-sized role in determining the quality of experience for your users. If you’re ready for a network redesign, this post can help you plan your approach.

If you are in need of a network refresh, where do you begin?

The first step to any successful infrastructure project is to develop a design that will enable your organization to grow with its ever-changing list of client and service delivery demands.  A portion of this requires you to evaluate your existing network usage and plan to build in capacity for future applications and projects.  You will also need to take into consideration any plans to move computing capacity into the cloud, like Microsoft Office 365 or Azure.  Your IT dollars might be better spent elsewhere and may lessen the costs for hardware refresh.  That said, you might find that your network infrastructure design could still use a few optimizations.

Loop-free design strategies

One of the popular trends that has been around for a few years now – from multiple switch manufacturers – is to create loop-free switched topologies as much as possible.  This creates an environment where waiting for spanning tree convergence is pretty much a thing of the past.  This is done by configuring multiple switch chassis to look and act like one switch or using switch stacks. In the distribution/access layers of your network, additional switch stacks will be provisioned with fully redundant, bonded, and loop-free links to the core.  The method for doing so will vary by vendor and model. This can be accomplished by utilizing distributed trunking (HP) or multichassis etherchannel (Cisco-VSS) or cross-stack etherchannel (Cisco 3850 et. al.) or vPC (Cisco Nexus).

The cookie cutter approach?

The win-win-win situation here is, once implemented, you gain bandwidth, loop-free topologies, as well as redundancy.  Also, as an added benefit, you can use the cookie cutter approach to create a consistent topology across the enterprise for ease of troubleshooting as well as management consolidation from the use of the technologies described above.  Managing 5 or 6 closets worth of switches, with 5 or 6 IP addresses, versus 20-30 IPs in the complicated legacy topologies is definitely worth its weight in silicon.

As I mentioned in my previous blog, Network Administrators are being asked to complete more and more tasks, but don’t necessarily have the time, the manpower, or the skillset to accomplish them all.  Having a simplified and improved network design, which grants you more bandwidth and redundancy, is a no-brainer!  If you need assistance with identifying how you can improve upon your legacy network design, Peters & Associates can help. Email We would love to help you sleep better at night!