Installing tcpdump for Android

• Download a tcpdump precompiled binary for ARM (Tcpdump-4.2.1-arm.tar.gz) from http://omappedia.org/wiki/USB_Sniffing_with_tcpdump. Decompress to obtain the tcpdump binary.
• Connect Android device to computer via USB cable, open a command terminal and execute the following commands:

adb push tcpdump /sdcard/tcpdump

adb shell

su

mount -o remount,rw /system

cat /sdcard/tcpdump > /system/bin/tcpdump

chown root:shell /system/bin/tcpdump

chmod 754 /system/bin/tcpdump

mount -o remount,ro /system

rm /sdcard/tcpdump

tcpdump -X -n -s 0 port 80

Source: https://josetrochecoder.wordpress.com/2013/11/04/installing-tcpdump-for-android/