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.
Network engineers like redundancy. It’s not that we just want double of everything – we want the networks we design and manage to be super fast, super smart, and super resilient. In the LAN and in the data center we’ve been logically joining network switches using technologies such as Cisco StackWise, the Virtual Switching System and Virtual Port Channels with fabric extenders in order to consolidate control and data plane activities and provide greater fault tolerance, easier management and multichassis etherchannel for path redundancy. These are great benefits, but they can be reaped only by proper design. Otherwise, an engineer may introduce more risk into the network rather than make it more resilient.
I get pretty excited when new network gear shows up at the loading dock. I get psyched when I get to configure an interesting technology that I rarely get to use. But considering our responsibility to our customer or employer, sometimes we need to put that aside in favor of the simpler (or cheaper) but more appropriate solution. Let me give you one example.
At Plexxi - fifth startup. Blogging since '06. Prior stops: 4 start-ups, 4 public companies and 4 years in investment management. I started in networking during the 5.25 inch disk era. I will probably write stuff you do not understand. I have been told I do not make people comfortable; deal with it. This is my personal blog and does not reflect the opinions of my employers.