Summary:
There are two desktop computers in my home:
One running Debian Linux and one running Windows 10.

They both access the Web through a wireless router (Verizon).

The issue:
1) I cannot use ssh from the Linux box in order to access the Windows box.
AND NOTE: That I can use ssh from the Windows box in order to access the Linux box.

2) In further 'testing', I cannot use ssh from the Windows box in order to access the Windows box.
AND NOTE: That I can use ssh from the Linux box in order to access the Linux box.

o I've tried ssh from OpenSSH and also from PuTTY with the same results.
o A firewall runs on the Windows box. But I get the same results whether it's up or down.
o I've tried both the IP address and the hostname.
o As a side note, the Linux box hosts an Apache Web server - which all of the household desktops successfully access.

++++++++++++++++++++++++++++++++++++
From Linux trying to get to Windows:
++++++++++++++++++++++++++++++++++++

OpenSSH:
--------
<1 of 2> ssh matt@HOME
ssh: connect to host home port 22: No route to host

<2 of 2>> ssh matt@192.168.1.2
ssh: connect to host 192.168.1.2 port 22: No route to host


PuTTY (ssh)
-----------
(Using HOME and 192.168.1.2)
No route to host


*****> Note that Linux-to-Linux works using both OpenSSH and PuTTY.


++++++++++++++++++++++++++++++++++++++++
From Windows trying to get to Windows:
++++++++++++++++++++++++++++++++++++++++

OpenSSH (from a DOS shell):
---------------------------
<1 of 2> C:\Windows\System32>ssh 192.168.1.2
ssh: connect to host 192.168.1.2 port 22: Connection timed out


<2 of 2> C:\Windows\System32>ssh HOME

****USAGE WARNING****

This is a private computer system. This computer system, including all
related equipment, networks, and network devices (specifically including
<SNIP>
constitutes consent to monitoring for these purposes.


matt@home's password:
Connection to home closed by remote host.
Connection to home closed.


PuTTY (ssh)
-----------
1) With IP -
Network error: Connection timed out
2) With HOME -
Server unexpectedly closed network connection


*****> Note that Windows-to-Linux works using both OpenSSH and PuTTY.


.
.
.
.
.
Anyone know what's going on?
TIA, Matt

Did you install openssh in windows and is it running?

Michaelk, thanks for the quick reply.

Yes and yes.

I assume cygwin and did you run the configuration script?
http://www.howtogeek.com/howto/41560...-using-cygwin/

No, it's not from Cygwin.
It's from http://www.openssh.com/.

And the ssh component of PuTTY, which also fails, is version 0.66 from http://www.chiark.greenend.org.uk/~sgtatham/putty/.

Also: the ssh configuration allows: "....I can use ssh from the Windows box in order to access the Linux box."

Thanks again.

As far as I know Windows openSSH runs via cygwin.

What happens when you run using localhost instead of a hostname or IP address.
c:\ssh localhost

Again, thanks for the reply.
ssh localhost via putty yields "PuTTY Fatal Error - Server unexpectedly closed network connection <OK>"

ssh in the DOS Command shell:

C:\Users\matt>ssh localhost

****USAGE WARNING****

This is a private computer system. This computer system, including all
related equipment, networks, and network devices (specifically including
Internet access) are provided only for authorized use. This computer system
may be monitored for all lawful purposes, including to ensure that its use
is authorized, for management of the system, to facilitate protection against
unauthorized access, and to verify security procedures, survivability, and
operational security. Monitoring includes active attacks by authorized entities
to test or verify the security of this system. During monitoring, information
may be examined, recorded, copied and used for authorized purposes. All
information, including personal information, placed or sent over this system
may be monitored.

Use of this computer system, authorized or unauthorized, constitutes consent
to monitoring of this system. Unauthorized use may subject you to criminal
prosecution. Evidence of unauthorized use collected during monitoring may be
used for administrative, criminal, or other adverse action. Use of this system
constitutes consent to monitoring for these purposes.


matt@localhost's password:
Connection to localhost closed by remote host.
Connection to localhost closed.

C:\Users\matt>

Well the server does appear to be running but no idea why you are getting the closed by remote host error.

Not sure if the windows ssh client supports the -v option but see what happens when you try:
ssh -v localhost

Here it is:

C:\Users\matt>ssh -v localhost
OpenSSH_7.2p1, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh_config
debug1: Connecting to localhost [::1] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2
debug1: match: OpenSSH_7.2 pat OpenSSH* compat 0x04000000
debug1: Authenticating to localhost:22 as 'matt'
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp521
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ecdsa-sha2-nistp521 SHA256:JteRLRjdOJBWjrZdrEcJYeZzM+dpRLIJfg7T1KLA2kI
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /home/matt/.ssh/known_hosts:5
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug1: SSH2_MSG_SERVICE_ACCEPT received

****USAGE WARNING****

This is a private computer system. This computer system, including all
related equipment, networks, and network devices (specifically including
Internet access) are provided only for authorized use. This computer system
may be monitored for all lawful purposes, including to ensure that its use
is authorized, for management of the system, to facilitate protection against
unauthorized access, and to verify security procedures, survivability, and
operational security. Monitoring includes active attacks by authorized entities
to test or verify the security of this system. During monitoring, information
may be examined, recorded, copied and used for authorized purposes. All
information, including personal information, placed or sent over this system
may be monitored.

Use of this computer system, authorized or unauthorized, constitutes consent
to monitoring of this system. Unauthorized use may subject you to criminal
prosecution. Evidence of unauthorized use collected during monitoring may be
used for administrative, criminal, or other adverse action. Use of this system
constitutes consent to monitoring for these purposes.


debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Trying private key: /home/matt/.ssh/id_rsa
debug1: Trying private key: /home/matt/.ssh/id_dsa
debug1: Trying private key: /home/matt/.ssh/id_ecdsa
debug1: Trying private key: /home/matt/.ssh/id_ed25519
debug1: Next authentication method: keyboard-interactive
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: password
matt@localhost's password:
debug1: Authentication succeeded (password).
Authenticated to localhost ([::1]:22).
debug1: channel 0: new [client-session]
debug1: Requesting no-more-sessions@openssh.com
debug1: Entering interactive session.
debug1: pledge: network
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug1: channel 0: free: client-session, nchannels 1
Connection to localhost closed by remote host.
Connection to localhost closed.
Transferred: sent 2132, received 3872 bytes, in 0.0 seconds
Bytes per second: sent 57729.2, received 104844.1
debug1: Exit status -1

C:\Users\matt>

Well, not much help so lets up the debug messages.

ssh -vvv localhost.

Why is Windoze trying to access /home/matt/.ssh/.... ?

Shouldn't it be something like C:\Users\matt\.ssh\.... ?

Or is that just internal where it translates the pathname?




C:\Windows\System32>ssh -vvv localhost
OpenSSH_7.2p1, OpenSSL 1.0.2g 1 Mar 2016
debug1: Reading configuration data /etc/ssh_config
debug2: resolving "localhost" port 22
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to localhost [::1] port 22.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/matt/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_7.2
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2
debug1: match: OpenSSH_7.2 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to localhost:22 as 'matt'
debug3: hostkeys_foreach: reading file "/home/matt/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/matt/.ssh/known_hosts:5
debug3: load_hostkeys: loaded 1 keys from localhost
debug3: order_hostkeyalgs: prefer hostkeyalgs: ecdsa-sha2-nistp256-cert-v01@openssh...01@openssh.com,ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521
debug3: send packet: type 20
debug1: SSH2_MSG_KEXINIT sent
debug3: receive packet: type 20
debug1: SSH2_MSG_KEXINIT received
debug2: local client KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: ecdsa-sha2-nistp256-cert-v01@openssh...01@openssh.com,ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128...cm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128...cm@openssh.com,aes128-cbc,aes192-cbc,aes256-cbc,3des-cbc
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm...28@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm...28@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib@openssh.com,zlib
debug2: compression stoc: none,zlib@openssh.com,zlib
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: curve25519-sha256@libssh.org,ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group14-sha1
debug2: host key algorithms: ssh-rsa,rsa-sha2-512,rsa-sha2-256,ecdsa-sha2-nistp521,ssh-ed25519
debug2: ciphers ctos: chacha20-poly1305@openssh.com,aes128...cm@openssh.com
debug2: ciphers stoc: chacha20-poly1305@openssh.com,aes128...cm@openssh.com
debug2: MACs ctos: umac-64-etm@openssh.com,umac-128-etm...28@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: umac-64-etm@openssh.com,umac-128-etm...28@openssh.com,hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,zlib@openssh.com
debug2: compression stoc: none,zlib@openssh.com
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: curve25519-sha256@libssh.org
debug1: kex: host key algorithm: ecdsa-sha2-nistp521
debug1: kex: server->client cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug1: kex: client->server cipher: chacha20-poly1305@openssh.com MAC: <implicit> compression: none
debug3: send packet: type 30
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug3: receive packet: type 31
debug1: Server host key: ecdsa-sha2-nistp521 SHA256:JteRLRjdOJBWjrZdrEcJYeZzM+dpRLIJfg7T1KLA2kI
debug3: hostkeys_foreach: reading file "/home/matt/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file /home/matt/.ssh/known_hosts:5
debug3: load_hostkeys: loaded 1 keys from localhost
debug1: Host 'localhost' is known and matches the ECDSA host key.
debug1: Found key in /home/matt/.ssh/known_hosts:5
debug3: send packet: type 21
debug2: set_newkeys: mode 1
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug3: receive packet: type 21
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug1: SSH2_MSG_NEWKEYS received
debug2: key: /home/matt/.ssh/id_rsa (0x0)
debug2: key: /home/matt/.ssh/id_dsa (0x0)
debug2: key: /home/matt/.ssh/id_ecdsa (0x0)
debug2: key: /home/matt/.ssh/id_ed25519 (0x0)
debug3: send packet: type 5
debug3: receive packet: type 7
debug1: SSH2_MSG_EXT_INFO received
debug1: kex_input_ext_info: server-sig-algs=<rsa-sha2-256,rsa-sha2-512>
debug3: receive packet: type 6
debug2: service_accept: ssh-userauth
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug3: send packet: type 50
debug3: receive packet: type 53
debug3: input_userauth_banner

****USAGE WARNING****

This is a private computer system. This computer system, including all
related equipment, networks, and network devices (specifically including
Internet access) are provided only for authorized use. This computer system
may be monitored for all lawful purposes, including to ensure that its use
is authorized, for management of the system, to facilitate protection against
unauthorized access, and to verify security procedures, survivability, and
operational security. Monitoring includes active attacks by authorized entities
to test or verify the security of this system. During monitoring, information
may be examined, recorded, copied and used for authorized purposes. All
information, including personal information, placed or sent over this system
may be monitored.

Use of this computer system, authorized or unauthorized, constitutes consent
to monitoring of this system. Unauthorized use may subject you to criminal
prosecution. Evidence of unauthorized use collected during monitoring may be
used for administrative, criminal, or other adverse action. Use of this system
constitutes consent to monitoring for these purposes.


debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: start over, passed a different list publickey,password,keyboard-interactive
debug3: preferred publickey,keyboard-interactive,password
debug3: authmethod_lookup publickey
debug3: remaining preferred: keyboard-interactive,password
debug3: authmethod_is_enabled publickey
debug1: Next authentication method: publickey
debug1: Trying private key: /home/matt/.ssh/id_rsa
debug3: no such identity: /home/matt/.ssh/id_rsa: No such file or directory
debug1: Trying private key: /home/matt/.ssh/id_dsa
debug3: no such identity: /home/matt/.ssh/id_dsa: No such file or directory
debug1: Trying private key: /home/matt/.ssh/id_ecdsa
debug3: no such identity: /home/matt/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: /home/matt/.ssh/id_ed25519
debug3: no such identity: /home/matt/.ssh/id_ed25519: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup keyboard-interactive
debug3: remaining preferred: password
debug3: authmethod_is_enabled keyboard-interactive
debug1: Next authentication method: keyboard-interactive
debug2: userauth_kbdint
debug3: send packet: type 50
debug2: we sent a keyboard-interactive packet, wait for reply
debug3: receive packet: type 51
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug3: userauth_kbdint: disable: no info_req_seen
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred:
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
matt@localhost's password:
debug3: send packet: type 50
debug2: we sent a password packet, wait for reply
debug3: receive packet: type 52
debug1: Authentication succeeded (password).
Authenticated to localhost ([::1]:22).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug3: send packet: type 90
debug1: Requesting no-more-sessions@openssh.com
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug3: receive packet: type 80
debug1: client_input_global_request: rtype hostkeys-00@openssh.com want_reply 0
debug3: receive packet: type 91
debug2: callback start
debug2: fd 3 setting TCP_NODELAY
debug3: ssh_packet_set_tos: set IPV6_TCLASS 0x10
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 1
debug3: send packet: type 98
debug2: channel 0: request shell confirm 1
debug3: send packet: type 98
debug2: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: send packet: type 1
debug1: channel 0: free: client-session, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 client-session (t4 r0 i0/0 o0/0 fd 4/5 cc -1)

Connection to localhost closed by remote host.
Connection to localhost closed.
Transferred: sent 2132, received 3872 bytes, in 0.1 seconds
Bytes per second: sent 24025.8, received 43634.1
debug1: Exit status -1

C:\Windows\System32>

I think I am stumped at the moment.