in the TLDK functional test, it try to use the tcpdump command to read the pcap files but the shell execute failed. we can found out the error information from the log file:

exec_command on ('10.30.51.190', 22): cd /tmp/TLDK-testing; /usr/sbin/tcpdump -nnnn -vvv -r ./tests/tldk/tldk_testconfig/test_ipv4_assemble_tx.pcap | grep 'udp sum ok' | wc –l

return STDERR bash: /usr/sbin/tcpdump: No such file or directory

it seems like the tcpdump tool not install in this version VIRL image, so i would like you to help install the tcpdump tool into the new version VIRL image.

the current VIRL image version is csit-ubuntu-16.04.1_2016-12-19_1.6