verbose tcpdump

tcpdump -nnvvXSs 1514 -i any

tcpdump specific mac dhcp (if mac = AA:EE:DD:0c:cf:08)

tcpdump -nnvvXSs 1514 -i any '((port 67 or port 68) and (udp[38:4] = 0x3e0ccf08))' 

nc connect to udp

nc -u host port

test tftp

tftp $ip
tftp> get /pxelinux.0
Transfer timed out.

tftp> get /pxelinux.0
tftp>