通过私有 IP 进行 SSH 即可
我能够通过 SSH 通过其私有 IP 地址连接到服务器：
C:\Users\m3>ssh -vvvvA [email protected]
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5
debug3: Failed to open file:C:/Users/m3/.ssh/config error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_config error:2
debug2: resolve_canonicalize: hostname 192.168.1.11 is address
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to 192.168.1.11 [192.168.1.11] port 22.
debug1: Connection established.
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_rsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_rsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_dsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_dsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ecdsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ecdsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519 error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ed25519 type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ed25519-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_xmss type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_7.7
debug1: Remote protocol version 2.0, remote software version OpenSSH_7.2p2 Ubuntu-4ubuntu2.10
debug1: match: OpenSSH_7.2p2 Ubuntu-4ubuntu2.10 pat OpenSSH* compat 0x04000000
debug2: fd 3 setting O_NONBLOCK
debug1: Authenticating to 192.168.1.11:22 as 'uconn'
debug3: hostkeys_foreach: reading file "C:\\Users\\m3/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file C:\\Users\\m3/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from 192.168.1.11
debug3: Failed to open file:C:/Users/m3/.ssh/known_hosts2 error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts2 error:2
debug3: order_hostkeyalgs: prefer hostkeyalgs: [email protected],[email protected],[email protected],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,[email protected],ecdh-sha2-nistp256,ecdh-sha2-nistp384,ecdh-sha2-nistp521,diffie-hellman-group-exchange-sha256,diffie-hellman-group16-sha512,diffie-hellman-group18-sha512,diffie-hellman-group-exchange-sha1,diffie-hellman-group14-sha256,diffie-hellman-group14-sha1,ext-info-c
debug2: host key algorithms: [email protected],[email protected],[email protected],ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521,[email protected],[email protected],ssh-ed25519,rsa-sha2-512,rsa-sha2-256,ssh-rsa
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none
debug2: compression stoc: none
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug2: peer server KEXINIT proposal
debug2: KEX algorithms: [email protected],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-nistp256,ssh-ed25519
debug2: ciphers ctos: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: ciphers stoc: [email protected],aes128-ctr,aes192-ctr,aes256-ctr,[email protected],[email protected]
debug2: MACs ctos: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: MACs stoc: [email protected],[email protected],[email protected],[email protected],[email protected],[email protected],[email protected],hmac-sha2-256,hmac-sha2-512,hmac-sha1
debug2: compression ctos: none,[email protected]
debug2: compression stoc: none,[email protected]
debug2: languages ctos:
debug2: languages stoc:
debug2: first_kex_follows 0
debug2: reserved 0
debug1: kex: algorithm: [email protected]
debug1: kex: host key algorithm: ecdsa-sha2-nistp256
debug1: kex: server->client cipher: [email protected] MAC: <implicit> compression: none
debug1: kex: client->server cipher: [email protected] 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-nistp256 SHA256:eyPiBvKLgJOk1xJc0k6cx9UnwIXbUUaXu9pPHTKt5Rg
debug3: hostkeys_foreach: reading file "C:\\Users\\m3/.ssh/known_hosts"
debug3: record_hostkey: found key type ECDSA in file C:\\Users\\m3/.ssh/known_hosts:1
debug3: load_hostkeys: loaded 1 keys from 192.168.1.11
debug3: Failed to open file:C:/Users/m3/.ssh/known_hosts2 error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_known_hosts2 error:2
debug1: Host '192.168.1.11' is known and matches the ECDSA host key.
debug1: Found key in C:\\Users\\m3/.ssh/known_hosts:1
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
debug1: SSH2_MSG_NEWKEYS received
debug2: set_newkeys: mode 0
debug1: rekey after 134217728 blocks
debug3: unable to connect to pipe \\\\.\\pipe\\openssh-ssh-agent, error: 2
debug1: pubkey_prepare: ssh_get_authentication_socket: No such file or directory
debug2: key: C:\\Users\\m3/.ssh/id_rsa (0000000000000000)
debug2: key: C:\\Users\\m3/.ssh/id_dsa (0000000000000000)
debug2: key: C:\\Users\\m3/.ssh/id_ecdsa (0000000000000000)
debug2: key: C:\\Users\\m3/.ssh/id_ed25519 (0000000000000000)
debug2: key: C:\\Users\\m3/.ssh/id_xmss (0000000000000000)
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 51
debug1: Authentications that can continue: publickey,password
debug3: start over, passed a different list publickey,password
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: C:\\Users\\m3/.ssh/id_rsa
debug3: no such identity: C:\\Users\\m3/.ssh/id_rsa: No such file or directory
debug1: Trying private key: C:\\Users\\m3/.ssh/id_dsa
debug3: no such identity: C:\\Users\\m3/.ssh/id_dsa: No such file or directory
debug1: Trying private key: C:\\Users\\m3/.ssh/id_ecdsa
debug3: no such identity: C:\\Users\\m3/.ssh/id_ecdsa: No such file or directory
debug1: Trying private key: C:\\Users\\m3/.ssh/id_ed25519
debug3: no such identity: C:\\Users\\m3/.ssh/id_ed25519: No such file or directory
debug1: Trying private key: C:\\Users\\m3/.ssh/id_xmss
debug3: no such identity: C:\\Users\\m3/.ssh/id_xmss: No such file or directory
debug2: we did not send a packet, disable method
debug3: authmethod_lookup password
debug3: remaining preferred: ,password
debug3: authmethod_is_enabled password
debug1: Next authentication method: password
debug3: failed to open file:C:/dev/tty error:3
debug1: read_passphrase: can't open /dev/tty: No such file or directory
[email protected]'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 192.168.1.11 ([192.168.1.11]: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 [email protected]
debug3: send packet: type 80
debug1: Entering interactive session.
debug1: pledge: network
debug1: console supports the ansi parsing
debug3: Successfully set console output code page from:437 to 65001
debug3: Successfully set console input code page from:437 to 65001
debug3: receive packet: type 80
debug1: client_input_global_request: rtype [email protected] want_reply 0
debug3: receive packet: type 91
debug2: channel_input_open_confirmation: channel 0: callback start
debug3: unable to connect to pipe \\\\.\\pipe\\openssh-ssh-agent, error: 2
debug1: ssh_get_authentication_socket: No such file or directory
debug2: fd 3 setting TCP_NODELAY
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: channel_input_open_confirmation: channel 0: callback done
debug2: channel 0: open confirm rwindow 0 rmax 32768
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: PTY allocation request accepted on channel 0
debug2: channel 0: rcvd adjust 2097152
debug3: receive packet: type 99
debug2: channel_input_status_confirm: type 99 id 0
debug2: shell request accepted on channel 0
Welcome to Ubuntu 16.04.7 LTS (GNU/Linux 4.4.0-206-generic i686)
* Documentation: https://help.ubuntu.com
* Management: https://landscape.canonical.com
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0 packages can be updated.
0 of these updates are security updates.
New release '18.04.5 LTS' available.
Run 'do-release-upgrade' to upgrade to it.
Last login: Tue Mar 23 14:22:05 2021 from 192.168.1.52
通过公网 IP 进行 SSH 操作是不好的
然而，当我使用其公共IP地址时，我遇到了一个错误：
ssh_exchange_identification：远程主机关闭连接
C:\Users\m3>ssh -vvvvA [email protected]
OpenSSH_for_Windows_7.7p1, LibreSSL 2.6.5
debug3: Failed to open file:C:/Users/m3/.ssh/config error:2
debug3: Failed to open file:C:/ProgramData/ssh/ssh_config error:2
debug2: resolve_canonicalize: hostname 11.111.11.111 is address
debug2: ssh_connect_direct: needpriv 0
debug1: Connecting to 11.111.11.111 [11.111.11.111] port 22.
debug1: Connection established.
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_rsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_rsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_rsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_dsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_dsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_dsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ecdsa type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ecdsa-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ecdsa-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519 error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ed25519 type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_ed25519-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_ed25519-cert type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_xmss type -1
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss-cert error:2
debug3: Failed to open file:C:/Users/m3/.ssh/id_xmss-cert.pub error:2
debug1: key_load_public: No such file or directory
debug1: identity file C:\\Users\\m3/.ssh/id_xmss-cert type -1
debug1: Local version string SSH-2.0-OpenSSH_for_Windows_7.7
ssh_exchange_identification: Connection closed by remote host
如何调试
可能是什么原因？我该如何调试该问题？
路由器端口转发
服务器有私有 IP 地址。但是有一个路由器，有公网 IP 地址，它将 SSH 22 端口转发到私有 IP 地址。
sshd日志
建议这里，我使用了这个命令服务器记录sshd输出：
$ tail -f -n 500 /var/log/auth.log | grep 'sshd'
当我跑上ssh [email protected]客户我收到以下日志：
Mar 23 17:26:10 server-homeshine sshd[1355]: Accepted password for uconn from 192.168.1.52 port 53107 ssh2
Mar 23 17:26:10 server-homeshine sshd[1355]: pam_unix(sshd:session): session opened for user uconn by (uid=0)
但当我继续ssh [email protected]客户，没有显示任何日志。我认为这暗示路由器不是22使用公网 IP 地址时转发端口。不知道为什么。
SSHD 配置
sshd配置服务器是：
uconn@server-homeshine:/etc/ssh$ cat sshd_config
# Package generated configuration file
# See the sshd_config(5) manpage for details
# What ports, IPs and protocols we listen for
Port 22
# Use these options to restrict which interfaces/protocols sshd will bind to
ListenAddress ::
ListenAddress 0.0.0.0
Protocol 2
# HostKeys for protocol version 2
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_dsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
HostKey /etc/ssh/ssh_host_ed25519_key
#Privilege Separation is turned on for security
UsePrivilegeSeparation yes
# Lifetime and size of ephemeral version 1 server key
KeyRegenerationInterval 3600
ServerKeyBits 1024
# Logging
SyslogFacility AUTH
LogLevel INFO
# Authentication:
LoginGraceTime 120
PermitRootLogin prohibit-password
StrictModes yes
RSAAuthentication yes
PubkeyAuthentication yes
#AuthorizedKeysFile %h/.ssh/authorized_keys
# Don't read the user's ~/.rhosts and ~/.shosts files
IgnoreRhosts yes
# For this to work you will also need host keys in /etc/ssh_known_hosts
RhostsRSAAuthentication no
# similar for protocol version 2
HostbasedAuthentication no
# Uncomment if you don't trust ~/.ssh/known_hosts for RhostsRSAAuthentication
#IgnoreUserKnownHosts yes
# To enable empty passwords, change to yes (NOT RECOMMENDED)
PermitEmptyPasswords no
# Change to yes to enable challenge-response passwords (beware issues with
# some PAM modules and threads)
ChallengeResponseAuthentication no
# Change to no to disable tunnelled clear text passwords
#PasswordAuthentication yes
# Kerberos options
#KerberosAuthentication no
#KerberosGetAFSToken no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
# GSSAPI options
#GSSAPIAuthentication no
#GSSAPICleanupCredentials yes
X11Forwarding yes
X11DisplayOffset 10
PrintMotd no
PrintLastLog yes
TCPKeepAlive yes
#UseLogin no
#MaxStartups 10:30:60
#Banner /etc/issue.net
# Allow client to pass locale environment variables
AcceptEnv LANG LC_*
Subsystem sftp /usr/lib/openssh/sftp-server
# Set this to 'yes' to enable PAM authentication, account processing,
# and session processing. If this is enabled, PAM authentication will
# be allowed through the ChallengeResponseAuthentication and
# PasswordAuthentication. Depending on your PAM configuration,
# PAM authentication via ChallengeResponseAuthentication may bypass
# the setting of "PermitRootLogin without-password".
# If you just want the PAM account and session checks to run without
# PAM authentication, then enable this but set PasswordAuthentication
# and ChallengeResponseAuthentication to 'no'.
UsePAM yes
IP 表
以下是 IP 表服务器：
$ sudo iptables -S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
$ sudo ip6tables -S
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
路由表
服务器路由表：
$ sudo route -n
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 enp9s0
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 enp9s0
Wireshark/Tshark
安装tshark于服务器并检查网络数据包，结果表明，在（私有 IP）上运行ssh [email protected]客户，SSH 数据包由服务器。
但在（公共 IP）上运行ssh [email protected]客户，没有收到 SSH 数据包服务器任何。
结论是 ADSL 路由器不是将 SSH 数据包转发到服务器。
ZyXEL 询问
就此问题联系了 ZyXEL 并收到以下答复：
当进行端口转发时，您需要确保内部服务器具有指向网关的网关地址，以便能够响应外部请求。
还要检查网关本身是否使用端口 22。
服务器默认网关
我的服务器默认网关192.168.1.1应该是这样的：
$ ip r
default via 192.168.1.1 dev enp9s0 onlink
192.168.1.0/24 dev enp9s0 proto kernel scope link src 192.168.1.11
答案1
出于安全原因，ISP 关闭了 22 号端口传入。通过联系 ISP 解决了这个问题。
将 SSHD 端口从 更改22为2222：
$ sudo vim /etc/ssh/sshd_config
$ sudo systemctl restart sshd
现在我可以使用自定义端口通过 SSH 连接到公共 IP 地址：
>ssh [email protected] -p 2222