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Jimm Chen
Asked: 2021-05-18 18:04:28 +0800 CST

Why netstat lists xinetd IPv6 TCP listen port, but not IPv4 port?

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On a Ubuntu 18.04 machine, I installed xinetd and inetutils-telnetd to serve TELNET clients, and it works well, accepting both clients from IPv6 clients and IPv4 clients.

One thing I notice is: netstat -ant lists tcp6 port 23 listen entry, but not tcp port 23 listen entry. Why is that?

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xinetd

1 Answers

  1. Best Answer

    The IPv6 socket listens also on IPv4, as long there isn't a IPv6-only flag set.

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