~ $ nc -l 1234
^Z
[1]+  Stopped                 nc -l 1234
~ $ bg 1
[1]+ nc -l 1234 &
~ $ echo "Test Test Test." | nc 10.0.0.1 1234 -q 1 && echo succeeded
~ $ echo "Test Test Test." | nc 10.0.0.3 1234 -q 1 && echo succeeded
Test Test Test.
succeeded
[1]+  Done                    nc -l 1234