Down latest Android tcpdump https://www.androidtcpdump.com/
install adb (this is Arch)
yaourt -Sy android-tools
adb push tcpdump /storage/emulated/0
adb shell
su
cp /storage/emulated/0 /system/bin/tcpdump
chmod 754 /system/bin/tcpdump
mount -o remount,ro /system
tcpdump -X -n -s 0 port 80
// sources https://josetrochecoder.wordpress.com/2013/11/04/installing-tcpdump-for-android/ https://www.androidtcpdump.com/