Here's a problem I ran into. I set up a new environment with a different layer 3 infrastructure. And everything seemed to be working. Until I got reports that some people couldn't get to one network in the new environment.
So, traffic going to the range 10.2.84.0/24 was working great for some people, but for others, it was not -- TCP connections would connect and then fail after a few seconds.
I spent a bunch of time looking at switch ports, and spanning tree, looking to see where the blocking ports were and making sure that there's no loops. So I gave up on that line of inquiry and started tracing back at layer 3.
Sure enough, there were two routes for 10.2.184.0/24 in one of my core routers - one of which pointed to the right place, and one of which pointed to the wrong place.
I deleted the wrong route, and things worked again.
- ▼ May (9)