I graduated college in 2001 with a degree in English and no strong direction for a vocation. After graduation I spent a few months working on the customer service desk at a supermarket while I thought through my next step. After what in hindsight was very little deliberation, I decided to go to graduate school for a Master’s degree and become a high school English teacher. Though I loved literature, writing, and being in the classroom, that became a short-lived career. After only a few years teaching Julius Caesar and T.S. Eliot, I started searching for something new.
Data center failover is an expensive, complex, and sometimes fragile component of a network design. Solving this one problem usually involves almost every other team in the IT department, and it’s inexorably linked with the very day-to-day operation of an organization.
How will a business recover from a data center outage?
How can mission critical applications move seamlessly between data centers?
How will our end-users reach an application in the event of a failover?
These are just a few high level questions that, along with very technical and legal requirements, will guide the actual design of a data center failover plan. The answers will determine bandwidth, routing protocols, storage, virtual environments, security, hardware platforms, and every minutia of design right down to how DNS will be propagated and what OSPF metrics are set to.
Recently I tried to join a Cisco 2702i access point to a 9800-CL wireless controller but found an issue that needed to be fixed prior to it joining successfully. I also recently joined a Catalyst 9115 access point right out of the box and experienced no issue at all, so my theory is that the 2702i had config still on it from when it was previously joined to a 5508 WLC. In this post I’ll go through the few steps I took to fix the issue and successfully join the 2702i to the 9800-CL.