tcpdump is a useful command to track traffic on your network.
To see all traffic between your PC and a remote server, run
tcpdump -i any host google.com
Here all traffic to google.com will be displayed.
To save the logs to a file, use
tcpdump -i any host google.com -w /tmp/test.pcap
Monitor taffic to all ports other than a specific port.
tcpdump -c 100 port not 3333
tcpdump -w /tmp/test.pcap -c 100 port not ssh
To view all communications on a specific port, for example port 993. use
tcpdump -i eth0 port 993