Есть три сервера. На двух авторизация по ключу работает. На одном - нет.
Ключ копировал так ssh-copy-id '-p XX stas@XXX.XXX.XXX.XXX'
$ ssh -o PreferredAuthentications=publickey -v XXX.XXX.XXX.XXX
OpenSSH_5.5p1 Debian-6+squeeze2, OpenSSL 0.9.8o 01 Jun 2010
debug1: Reading configuration data /home/stas/.ssh/config
debug1: Applying options for vps
debug1: Reading configuration data /etc/ssh/ssh_config
debug1: Applying options for *
debug1: Connecting to XXX.XXX.XXX.XXX [XXX.XXX.XXX.XXX] port XXX.
debug1: Connection established.
debug1: identity file /home/stas/.ssh/id_rsa type 1
debug1: Checking blacklist file /usr/share/ssh/blacklist.RSA-2048
debug1: Checking blacklist file /etc/ssh/blacklist.RSA-2048
debug1: identity file /home/stas/.ssh/id_rsa-cert type -1
debug1: identity file /home/stas/.ssh/id_dsa type -1
debug1: identity file /home/stas/.ssh/id_dsa-cert type -1
debug1: Remote protocol version 2.0, remote software version OpenSSH_5.5p1 Debian-6+squeeze2
debug1: match: OpenSSH_5.5p1 Debian-6+squeeze2 pat OpenSSH*
debug1: Enabling compatibility mode for protocol 2.0
debug1: Local version string SSH-2.0-OpenSSH_5.5p1 Debian-6+squeeze2
debug1: SSH2_MSG_KEXINIT sent
debug1: SSH2_MSG_KEXINIT received
debug1: kex: server->client aes128-ctr hmac-md5 none
debug1: kex: client->server aes128-ctr hmac-md5 none
debug1: SSH2_MSG_KEX_DH_GEX_REQUEST(1024<1024<8192) sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_GROUP
debug1: SSH2_MSG_KEX_DH_GEX_INIT sent
debug1: expecting SSH2_MSG_KEX_DH_GEX_REPLY
debug1: checking without port identifier
debug1: Host 'XXX.XXX.XXX.XXX' is known and matches the RSA host key.
debug1: Found key in /home/stas/.ssh/known_hosts:1
debug1: found matching key w/out port
debug1: ssh_rsa_verify: signature correct
debug1: SSH2_MSG_NEWKEYS sent
debug1: expecting SSH2_MSG_NEWKEYS
debug1: SSH2_MSG_NEWKEYS received
debug1: Roaming not allowed by server
debug1: SSH2_MSG_SERVICE_REQUEST sent
debug1: SSH2_MSG_SERVICE_ACCEPT received
debug1: Authentications that can continue: publickey,password
debug1: Next authentication method: publickey
debug1: Offering public key: /home/stas/.ssh/id_rsa
debug1: Authentications that can continue: publickey,password
debug1: Trying private key: /home/stas/.ssh/id_dsa
debug1: No more authentication methods to try.
Permission denied (publickey,password).
