Understanding bugs on Java/Python is quite interesting, but sometimes we have issues with the network. On those cases, we have the tcpdumps to help:
tcpdump basically is a common packet analyzer that runs under the command line, as in:
#sudo tcpdump -D
Btw, reading is much more difficult than actually capturing the data.
For only IPV6 traffic you can use:
For HTTPS get/post dump, the command is here:
sudo tcpdump -s 0 -v -n -l | egrep -i "POST /|GET /|Host:"
Some examples can be found here