ref: 7c62868a9fb501b132cb9d2a24b38a19edf13a90
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.