How Can I Monitor TCP Kernel Stats?

You can either use the kernel's built-in tcp_trace() routines or insert your own printfs. It's always a help, though, to run your application in socket debug mode so you know exactly which connection your TCP statistics are for.

Using trpt and tcp_trace()

• Compile a kernel with "options TCPDEBUG" in the config file
• Run trpt to process the debug info saved by the kernel.

Using console and tcp_trace()

• Run an application with a socket in debug mode (socket option SO_DEBUG)
• Set "options TCPCONSDEBUG" to dump the debugging info to the console, where you can look at it with dmesg or in /var/log/messages.

Using console and printfs

• Run an application with a socket in debug mode (socket option SO_DEBUG)
• Use "if (so->so_options & SO_DEBUG)" around the printfs.
• Put printfs in the code and the output will go to the console which you can look at it with dmesg or in /var/log/messages.