I’m recording this week at BSDCan. While I got away from the power drill, I fear there’s noise from the highway. Sorry. Here’s a bit from the new Networking for System Administrators.
Without tcpdump, I would have had to open a trouble ticket with the network team. They would have told me that they were allowing SSH traffic between these two hosts. They might have fired up their own packet sniffer so they could watch me replicate the problem. They would have informed me that my server was rejecting the connection. That would contradict my live92d experience of being currently logged into this host via SSH, and would therefore be suspect. What do we do with suspicious information? We experience emotional distress and push back. In this case, the network people would be correct and me pushing back would have imposed my emotional distress on them. Working for a living is bad enough without someone looking dumb and everyone’s feelings getting unnecessarily hurt. Use tcpdump. Even if you still have to ask the network team for help, there’s a world of difference between “you have to be blocking my traffic because it isn’t working” and “I am utterly stumped, any suggestions?” Don’t destroy trust; build it.
The new edition will hit Kickstarter in September.