Using tcpdump to trace IP of strangers(predators) on omegle

I am using tcpdump to capture packets while being on omegle. However, I have been fairly unsuccessful to get strangers IP. All the IP I see are traced back to either 172...* which is for google 104.23.. for omegle and some servers. Now, commands I’ve used are
tcpdump -nn src 192.168.42.152, which is my src address,
Have also tried
tcpdump -ttnnvvS for complete raw output. But in vain. Am I doing it wrong? I remember using wireshark and it was pretty easy with it, but don’t happen to have wireshark at the moment.
Also note that, I am not using the IP for any sort of illegal activity nor am I using it to pull a silly prank on anyone.
Wanna help me out a bit here? Are there any other ways except wireshark to do that?
Also, ethernet was my only interface hence no -i eth0.