So habe eben meinem Befehl noch ein -v hinzugefügt. Hier die Rückgabe:
pi@raspberrypi:~ $ ssh -p2000 -v -fNC -R 10011:localhost:22 Sebastian@XXX.XXX.XXX.XXX
OpenSSH_6.7p1 Raspbian-5+deb8u3, OpenSSL 1.0.1t 3 May 2016
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: /etc/ssh/ssh_config line 19: Applying options for *
debug1: Connecting to XXX.XXX.XXX.XXX [XXX.XXX.XXX.XXX] port 2000.
debug1: Connection established.
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_rsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_rsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_dsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_dsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_ecdsa type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_ecdsa-cert type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_ed25519 type -1
debug1: key_load_public: No such file or directory
debug1: identity file /home/pi/.ssh/id_ed25519-cert type -1
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_6.7p1 Raspbian-5+deb8u3
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.2
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.2 pat OpenSSH* compat 0x04000000
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr umac-64-etm@openssh.com zlib@openssh.com
debug1: kex: client->server aes128-ctr umac-64-etm@openssh.com zlib@openssh.com
debug1: sending SSH2_MSG_KEX_ECDH_INIT
debug1: expecting SSH2_MSG_KEX_ECDH_REPLY
debug1: Server host key: ECDSA 34:63:9d:9c:59:71:2f:f8:e5:19:a0:08:22:5c:35:c2
debug1: checking without port identifier
debug1: Host 'XXX.XXX.XXX.XXX' is known and matches the ECDSA host key.
debug1: Found key in /home/pi/.ssh/known_hosts:1
debug1: found matching key w/out port
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: publickey
debug1: Trying private key: /home/pi/.ssh/id_rsa
debug1: Trying private key: /home/pi/.ssh/id_dsa
debug1: Trying private key: /home/pi/.ssh/id_ecdsa
debug1: Trying private key: /home/pi/.ssh/id_ed25519
debug1: Next authentication method: keyboard-interactive
debug1: Authentications that can continue: publickey,password,keyboard-interactive
debug1: Next authentication method: password
Sebastian@XXX.XXX.XXX.XXX's password:
debug1: Authentications that can continue: publickey,password,keyboard-interactive
Permission denied, please try again.
sebastian@sebastian-X75A1:~$ ls -l .ssh
insgesamt 4
-rw-r--r-- 1 sebastian sebastian 395 Dez 9 17:51 known_hosts
Fehlen mir irgendwelche files? Ich mach nun erstmal Feierabend. 