Grab UDP
tcpdump -n udp dst portrange 1-9999 -v -w capture.cap
Show icmp live
tcpdump -v icmp
Viewing dumps
tcpdump -qns 0 -A -r capture.cap
tcpdump -ttttnnr capture.cap
tcpdump -vvv -r capture.cap
tcpick -C -yP -r capture.cap
http://rationallyparanoid.com/articles/tcpdump.html