ref: b117d7014da620fb2aa8de900c2c4a57fefe5f19
dir: /sys/man/8/udpecho/
.TH UDPECHO 8 .SH NAME udpecho \- echo UDP packets .SH SYNOPSIS .PP .B ip/udpecho [ .B -x .I ext ] .SH DESCRIPTION .PP Listen on UDP port 7 and echo back any packets received. This should only be run for testing since it can be used to disguise the identity of someone doing a denial of service attack.