Netcat

netcat is a tool for using and testing TCP.

NOTE:

netcat has been superceeded by ss

Install

pacman -S openbsd-netcat

Usage

Common Flags

nc \
  -u  # send udp packets \
  -v  # verbose \
  -z  # check if reachable \

Port Testing

nc -vz    x.x.x.x 80                      # ipv4 confirm port 80 open
nc -6 -vz xxxx:xxxx:xxx:xx::xxx::xxxx 80  # ipv6 confirm port 80 open

Listen/Send on Port

nc -l -p 6001                     # Listen to port 6001 on localhost

echo "hello" | nc 127.0.0.1 6001  # Send test 'hello' to port 6001 on localhost

Listen/Send on FIFO

mkfifo /var/temp.sock
nc -U /var/temp.sock         # listen on fifo