As much as I love to call out a vendor on marketing nonsense, Ramesh Prabagaran, Director of Product Management at Cisco, made some compelling marketing statements about SD-WAN at Networking Field Day 19. In particular he said:
There are a small variety of methods to implement failover of your WAN perimeter between two ISPs. In this post we’ll look at one way to accomplish this goal with a few technical requirements.
Keep in mind that there are several ways to accomplish this same goal depending on the hardware available, the flexibility of the ISPs, and the skill level or preference of the engineer.
This topology utilizes two edge routers and two ISPs instead of the single edge router design I wrote about recently (you can read that here). For this post we’re using Cisco routers, but the concepts apply universally. Our requirements are that we maintain connectivity from our inside host to the internet in the event one of the company routers fails or one of the ISPs fails. Failover and fail-back must be automatic with no manual intervention.
No Networking Field Day would be complete without a presentation from an SD-WAN vendor. The technology is now established and maturing into a ubiquitous WAN solution across small and large enterprises alike, so at the upcoming Networking Field Day 15, I’ll be focused on how TELoIP, one of the presenters at the event, differentiates itself from its competitors.
Sometimes political, financial, or logistical hurdles determine how we solve networking problems. In these tricky situations we may not be able to solve the problem the way we’d prefer, but we still need to solve the problem.
In this post I’m going to look at how we can solve a WAN failover scenario when we have a default route learned from both of our service providers and a reachability problem via our primary ISP.
It looks like we’re going to have some SD-WAN goodness next week at Networking Field Day 13. I love the technology itself because of the real-world use case and practical benefits a good SD-WAN solution can offer. Many of the SDN-labeled offerings out there are still a little immature, but adding intelligence to the WAN edge is something that is already being adopted wholeheartedly in even small enterprises.