Tracking down DNS issues
This was a good experience on tracking down a DNS issue at IMC, when I had no practical network debugging experience. tldr try to get the network tuple to help diagnose general networking issues nslookup / dig will get the DNS record for you tcpdump can determine if network traffic is making it in / out of a server traceroute / mtr will determine at which hop packets are getting dropped The issue It was noticed that cronjobs on a particular host were failing with DNS errors, and was intermittently unable to send requests:...