[kaiken1987]

Wireshark is fantastic. It also great for listening in on USB connections. The only issue I have with it is I have to use a secondary program to capture the loopback. But rawcap is small lightweight and easy is its not a huge issue

[woodrowbarlow]

if i recall correctly, this is a windows-only limitation. i've had no problems capturing loopback on linux. on windows, you can install npcap rather than winpcap to allow capturing on the loopback with wireshark.