ssh-connection from outside (and inside) fails -- Linux Mint

Question

PROBLEM

• no ssh connection to my local computer possible, even not ssh [myname]:127.0.0.1

• ssh localhost, on the other hand, works

• entering sshd: ALL and ssh: ALL in /etc/hosts.allow does not help

• turning off the router's firewall does not help either

Your help would be appreciated!

DETAILS

**sudo ss -tulpn | grep :22** yields

tcp     LISTEN   0        128              0.0.0.0:22             0.0.0.0:*      users:(("sshd",pid=1075,fd=4))                                                 
tcp     LISTEN   0        128                 [::]:22                [::]:*      users:(("sshd",pid=1075,fd=3))

**ssh -X -vvv [myname]@[my-ip-address]**  [typical login attempt from somewhere outside, various places & networks]

OpenSSH_8.9p1 Ubuntu-3ubuntu0.7, OpenSSL 3.0.2 15 Mar 2022
debug1: Reading configuration data /users/[myname]/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 3: Applying options for *
debug2: resolve_canonicalize: hostname [my_ip_address] is address
debug1: hostname canonicalisation enabled, will re-parse configuration
debug1: re-parsing configuration
debug1: Reading configuration data /users/[myname]/.ssh/config
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 3: Applying options for *
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts' -> '/users/[myname]/.ssh/known_hosts'
debug3: expanded UserKnownHostsFile '~/.ssh/known_hosts2' -> '/users/[myname]/.ssh/known_hosts2'
debug3: ssh_connect_direct: entering
debug1: Connecting to [my-ip-address] [[my-ip-address]] port 22.
debug3: set_sock_tos: set socket 4 IP_TOS 0x10
debug1: connect to address [my-ip-address] port 22: Connection timed out

**netstat -tnlp**  (Not all processes could be identified, non-owned process info will not be shown, you would have to be root to see it all.)

Active Internet connections (only servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
tcp        0      0 127.0.0.53:53           0.0.0.0:*               LISTEN      -                   
tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      -                   
tcp        0      0 127.0.0.1:631           0.0.0.0:*               LISTEN      -                   
tcp6       0      0 :::22                   :::*                    LISTEN      -                   
tcp6       0      0 ::1:631                 :::*                    LISTEN      -    

**ps -ef | grep sshd**

root        1075       1  0 12:48 ?        00:00:00 sshd: /usr/sbin/sshd -D [listener] 0 of 10-100 startups
[myname]        21645   16166  0 14:50 pts/4    00:00:00 grep --color=auto sshd

**Firewall:** none on my machine, turning off the router's firewall does not change anything

On my computer sshd (root) and ssh-client ([myname]) are running

**telnet [my-ip-address] 22** is taciturn and quits after some time

**ping** to my machine works fine