From here on, we will suppose that your IP address is 126.96.36.199 and that the IP address of the person at the other end is 188.8.131.52.
You should replace these example addresses with the real IP addresses involved. 7
Step 5. Confirm IP addresses and test connectivity to ensure that both you and the person at the other end have correctly determined your IP addresses, try to perform some operation that allows you to communicate with one another by specifying each other’s IP addresses.
You could use the ping command or try the application that you eventually plan to test out, such as a P2P file-sharing client or VoIP application.
If you can’t establish some kind of end-to-end communication using the IP addresses you’ve determined, you’ll need to debug this problem before proceeding any further.
Possible causes could include the presence of a firewall, including a software firewall that has not yet been disabled at one end.
Step 6. Synchronize computer clocksIf your operating system supports it, make sure that your computer’s clock is synchronized to an authoritative Network Time Protocol (NTP) network time server, so that the dates and times recorded in your packet capture will be accurate and will correspond to those recorded by the other computer. This will help make results or log entries from multiple computers easier to compare.