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skwokie
Asked: 2019-08-14 10:37:21 +0800 CST

nc prints (?). What does (?) mean?

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When I use nc to test a port as followed, it prints out a result with '(?)' in it. I've looked up the man page and also online but I can't find an answer. Can someone please shed some lights? Thanks.

# nc -v -u -w 3 localhost 10003
localhost [127.0.0.1] 10003 (?) open

I have netcat-traditional 1.10-41.1

netcat

1 Answers

  1. Thanks to Michael for the point-out. It was the traditional flavor. I just installed the openbsd flavor and it prints the result properly now:

    # nc -v -u -w 3 localhost 10000
Connection to localhost 10000 port [udp/*] succeeded!
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