When a service "can't connect," the app logs and the network rarely tell the same story. tcpdump settles the argument: it shows what actually went over the wire, not what the client library claims happened. Learning to read three packet signatures is usually enough to split a network problem fr...
Source: [Dev.to](https://dev.to/jjoyneriv/tcpdump-for-devops-read-a-tcp-handshake-and-stop-guessing-3a2f)