Strange network problem after fresh install

[Pierre Dupond <76nemo76%gmx.ch@localhost>]

Hi All,
       I have done a fresh NetBSD 9.0 install. Ipv6 and Ipv4 are configured.
Network connectivity to outside is working correctly but almost all
network connections to the machine are blocked.

The commands: "ping localhost" or "ssh localhost" works well
but if I replace localhost by the IP Address (ping 192.168.1.23)
I get no answer.

Any idea?

Thanks for your help.

Best regards,
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