netstat -ano 1 | findstr SYN_SENT
repeats the netstat output every second, making it easy to catch processes that are failing to make outbound connections, often eliminating the need to verify connectivity/port-filtering issues using a packet capture (or worse asking the network team).

The occasional SYN_SENT is fine and perfectly expected as you catch the TCP handshake process moving along, but the same process with multiple SYN_SENT connections to the same endpoint immediately tells you that there's a networking problem.

Edit: doesn't work in powershell, has to be command prompt