Fail to SSH log onto a MacOS server

Date: 2025-03-02 Error when SSH onto a MacOS error:

kex_exchange_identification: read: Connection reset by peer
Connection reset by <My IP Address...> port 22

Background

This server is connected via tailscale network and SSH login is enabled.

Solving

First try checking the log.

sudo log stream --predicate 'process == "sshd"' --info

Got these log information on my server:

Timestamp                       Thread     Type        Activity             PID    TTL
2025-03-02 23:07:56.155362+0800 0x15e23a   Error       0x0                  44960  0    sshd: (libsystem_info.dylib) [com.apple.network.libinfo:si_destination_compare] send failed: Invalid argument
2025-03-02 23:07:56.155878+0800 0x15e23a   Error       0x0                  44960  0    sshd: (libsystem_info.dylib) [com.apple.network.libinfo:si_destination_compare] send failed: Invalid argument
2025-03-02 23:07:56.155900+0800 0x15e23a   Error       0x0                  44960  0    sshd: (libsystem_info.dylib) [com.apple.network.libinfo:si_destination_compare] send failed: Invalid argument
2025-03-02 23:07:56.157492+0800 0x15e23a   Info        0x0                  44960  0    sshd: sshd: no hostkeys available -- exiting.

It turns out that tailscale is wrongly set. Allow Local Network Access should be enabled!