sftp连接太多的publickey验证尝试都出错了

我正在尝试进行sftp连接。目的地使用公钥+密码认证和端口2222。

我能够从现有的linux主机连接到目的地。我们现有的linux主机使用Openssh_5.3。

sftp -v -oPort=2222 -oIdentityFile=/home/xyz/.ssh/abc/id_rsa user@sftp.abc.com
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering public key: /home/xyz/.ssh/abc/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: read PEM private key done: type RSA
Authenticated with partial success.
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering public key ...
...
debug1: Next authentication method: keyboard-interactive
Here it goes to the next authentication method keyboard-interactive with no problem.

我无法从我们的下一个linux主机连接。它使用OpenSSH_6.6.1。我们的新linux主机具有相同的出站IP，目标不是按IP地址过滤连接。我正在使用完全相同的私钥文件和sftp命令。所以这似乎是一个ssh问题？

我得到的错误是：

sftp -v -oPort=2222 -oIdentityFile=/home/xyz/.ssh/abc/id_rsa user@sftp.abc.com
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering RSA public key: /home/xyz/.ssh/abc/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
Authenticated with partial success.
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering RSA public key: ....
......
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering RSA public key: /home/xyz/.ssh/abc/id_rsa
debug1: Server accepts key: pkalg ssh-rsa blen 277
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
Authenticated with partial success.
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Offering RSA public key: ....
......
Here it goes as infinite loop and keep trying the same private key again and again (although it already got partial success)
until it got "**Too many publickey verification attempts were made**" error.

如果我用-vvv运行，这是输出：

debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Trying private key: /home/xyz/.ssh/abc/id_rsa
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey: RSA 7f:69:c6:c9:be:54:6e:7a:35:7d:63:b6:7f:28:0f:20
debug2: we sent a publickey packet, wait for reply
Authenticated with partial success.
debug2: key: /home/xyz/.ssh/abc/id_rsa ((nil)), explicit
debug2: key: /home/xyz/.ssh/id_rsa ((nil)),
debug2: key: /home/xyz/.ssh/id_dsa ((nil)),
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Trying private key: /home/xyz/.ssh/abc/id_rsa
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey: RSA 7f:69:c6:c9:be:54:6e:7a:35:7d:63:b6:7f:28:0f:20
debug2: we sent a publickey packet, wait for reply
Authenticated with partial success.
debug2: key: /home/xyz/.ssh/abc/id_rsa ((nil)), explicit
debug2: key: /home/xyz/.ssh/id_rsa ((nil)),
debug2: key: /home/xyz/.ssh/id_dsa ((nil)),
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Trying private key: /home/xyz/.ssh/abc/id_rsa
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey: RSA 7f:69:c6:c9:be:54:6e:7a:35:7d:63:b6:7f:28:0f:20
debug2: we sent a publickey packet, wait for reply
Authenticated with partial success.
debug2: key: /home/xyz/.ssh/abc/id_rsa ((nil)), explicit
debug2: key: /home/xyz/.ssh/id_rsa ((nil)),
debug2: key: /home/xyz/.ssh/id_dsa ((nil)),
debug1: Authentications that can continue: password,publickey,keyboard-interactive
debug1: Trying private key: /home/xyz/.ssh/abc/id_rsa
debug1: key_parse_private2: missing begin marker
debug1: read PEM private key done: type RSA
debug3: sign_and_send_pubkey: RSA 7f:69:c6:c9:be:54:6e:7a:35:7d:63:b6:7f:28:0f:20
debug2: we sent a publickey packet, wait for reply

This goes on again and again, so I just killed it.