Sniffer for localhost (Windows OS) [closed]

I was faced with this issue and got nowhere after a lot of research. Basically all available sniffers rely on the network driver stack, and Windows don't expose localhost calls through it.

What I ended up using was a tool called SocketSniffer, that peeks at Winsock's calls and monitor TCP, UDP socket connections. It helped me debug an application problem that only occurred in win 2k3.

Its download site is at http://www.nirsoft.net/utils/socket_sniffer.html

Note that this no longer works in Windows 8. Microsoft Message Analyzer is now capable of sniffing loopback traffic out of the box. Official blog post here: http://blogs.msdn.com/b/winsdk/archive/2014/08/15/rejoice-we-can-now-capture-loopback-traffic.aspx

There is a new tool available for Windows that can capture looback / localhost network traffic. It is called RawCap and is available here:http://www.netresec.com/?page=RawCap

Just start RawCap like this to sniff the loopback interface:RawCap.exe 127.0.0.1 localhost.pcap

You can then open localhost.pcap in Wireshark or any other pcap analyzer to look at the capured traffic.

Btw. not only is RawCap able to sniff loopback traffic on Windows, it can also sniff your WiFi interface as well as PPP interfaces such as 3G/UMTS connections.

I believe you can do http://localhost./ (note the period at the end) to force localhost packets through the regular network stack.

This works for getting http to be recognized by a tool like fiddler - not sure about other protocols.