我正在尝试利用 ssh 的跳转主机选项，但由于某种原因它不起作用，我得到：
$ ssh -J user1@host1 user2@target
kex_exchange_identification: banner line contains invalid characters
banner exchange: Connection to UNKNOWN port 65535: invalid format
$ ssh -J user1@host1:22 user2@target:22
channel 0: open failed: connect failed: Name or service not known
stdio forwarding failed
kex_exchange_identification: Connection closed by remote host
Connection closed by UNKNOWN port 65535
我想知道为什么，我可以通过 ssh 从用户笔记本登录到 host1，然后从 host1 登录到目标。我也设置了所有键。我很困惑，我错过了什么？
添加后-v，我可以观察到以下内容：
debug1: kex_exchange_identification: banner line 39: \033[?25h\033[?7hSSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
kex_exchange_identification: banner line contains invalid characters
banner exchange: Connection to UNKNOWN port 65535: invalid format
debug1: channel 0: free: direct-tcpip: listening port 0 for target port 22, connect from 127.0.0.1 port 65535 to UNKNOWN port 65536, nchannels 1
debug1: fd 0 clearing O_NONBLOCK
Killed by signal 1.
请注意，我可以从 LAN 上的其他主机正常连接，target但ssh -J user1@host1 user2@target只有这台主机似乎无法连接。
当我将该行更改为 时ssh -J user1@host1:22 user2@target:22 -v，我得到以下信息：
debug1: client_input_hostkeys: no new or deprecated keys from server
debug1: Remote: /home/user1/.ssh/authorized_keys:3: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
debug1: Remote: /home/user1/.ssh/authorized_keys:3: key options: agent-forwarding port-forwarding pty user-rc x11-forwarding
channel 0: open failed: connect failed: Name or service not known
stdio forwarding failed
kex_exchange_identification: Connection closed by remote host
Connection closed by UNKNOWN port 65535
它想做什么port 65535？我还通过 ssh 访问host1并执行了以下操作：
netcat target 22
SSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
在 后touch ~/.hushlogin，添加更多-vs，并-vvv附加 I 得到；
debug2: channel 0: open confirm rwindow 2097152 rmax 32768
debug1: kex_exchange_identification: banner line 39: \033[?25h\033[?7hSSH-2.0-OpenSSH_7.6p1 Ubuntu-4ubuntu0.3
kex_exchange_identification: banner line contains invalid characters
banner exchange: Connection to UNKNOWN port 65535: invalid format
debug3: send packet: type 1
debug1: channel 0: free: direct-tcpip: listening port 0 for ghnvm port 22, connect from 127.0.0.1 port 65535 to UNKNOWN port 65536, nchannels 1
debug3: channel 0: status: The following connections are open:
#0 direct-tcpip: listening port 0 for ghnvm port 22, connect from 127.0.0.1 port 65535 to UNKNOWN port 65536 (t4 r0 i0/0 o0/0 e[closed]/0 fd 4/5/-1 sock -1 cc -1)
debug1: fd 0 clearing O_NONBLOCK
debug3: fd 1 is not O_NONBLOCK
Killed by signal 1.
甚至ssh -oProxyCommand='ssh -p22 user1@host1 -W %h:%p' -p22 user2@target会返回：
kex_exchange_identification: banner line contains invalid characters
banner exchange: Connection to UNKNOWN port 65535: invalid format