I'm troubleshooting my aCal installation and the good folks at aCal asked me for the output from
tcpdump -A -- do I need to root my phone and install busybox or can I do this from a terminal emulator?
Yes, tcpdump is an administrator-level application (I highly doubt there will ever be an Android permission level to view all other apps' network traffic). Once rooted, if you have tcpdump binary (compiled for your device's cpu type) on sdcard, try:
su mount -o remount rw /system/ cd /sdcard cp ./tcpdump /system/xbin
Now you can use tcpdump command.