Idea for a new hobby:
Collecting network packet capture (pcap) traces from interesting/"fun" network environments. :3
In the same way other people collect stamps or whatever.

"Look at this weird setup with multiple DHCP servers!"
"I've got one where the timings are totally off!"
... you could also trade them if you're comfortable. :D

If you've never made a packet capture trace before, here's how you can get started using Wireshark: https://www.howtogeek.com/104278/how-to-use-wireshark-to-capture-filter-and-inspect-packets/
If you prefer video instructions: https://www.youtube.com/watch?v=Ov3BRzGziCw

@NerdResa cool, thanks for sharing. Wireshark and the amount of data you might end up with initially seem scary but it is not so bad when you use filters to narrow down the data you need.

I was impressed to see a Gigaset Maxwell 3 VOIP phone I provided for work with debug facilities on the web configuration that capture and display SIP packets going to and from the device (useful especially if working across firewalls where SIP can be a challenge to get working), although these aren't cheap!