debugging tcp/ip applications tips

Some programs, tools, tips that I found usefull to debug tcp/ip applications:

-netstat command to see the display active tcp/ip connections and ports in each the computer is listening. Some usefull options are /a and /n

-ethereal network analyzer software once you know what are the ips and the ports you can observe the messages being exchanged for active connections

-write either a client or server using Python to reproduce and test fixes

-vmware can help too