我编辑了我的 SSH 配置以接受端口 213 上的连接，因为它是我的工作防火墙允许通过的少数端口之一。
然后我重新启动了 sshd，一切正常。
我在本地测试了 ssh 服务器，并检查 sshd 服务是否在端口 213 上监听；但是，我仍然无法让它在本地主机之外工作。
PuTTY 显示连接被拒绝消息，并且我尝试过的一些允许检查端口的站点说端口已关闭。
对我来说，这要么是防火墙，要么是端口转发。但我已经为其添加了入站和出站例外。
这是我的服务器主机的问题吗，还是我遗漏了什么？
根据要求，我的完整 SSH 配置文件：
# $OpenBSD: sshd_config,v 1.73 2005/12/06 22:38:28 reyk Exp $
# This is the sshd server system-wide configuration file. See
# sshd_config(5) for more information.
# This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin
# The strategy used for options in the default sshd_config shipped with
# OpenSSH is to specify options with their default value where
# possible, but leave them commented. Uncommented options change a
# default value.
Port 22
Port 213
#Protocol 2,1
Protocol 2
#AddressFamily any
#ListenAddress 0.0.0.0
#ListenAddress ::
# HostKey for protocol version 1
#HostKey /etc/ssh/ssh_host_key
# HostKeys for protocol version 2
#HostKey /etc/ssh/ssh_host_rsa_key
#HostKey /etc/ssh/ssh_host_dsa_key
# Lifetime and size of ephemeral version 1 server key
#KeyRegenerationInterval 1h
#ServerKeyBits 768
# Logging
# obsoletes QuietMode and FascistLogging
#SyslogFacility AUTH
SyslogFacility AUTHPRIV
#LogLevel INFO
# Authentication:
#LoginGraceTime 2m
#PermitRootLogin yes
#StrictModes yes
#MaxAuthTries 6
#RSAAuthentication yes
#PubkeyAuthentication yes
#AuthorizedKeysFile .ssh/authorized_keys
# For this to work you will also need host keys in /etc/ssh/ssh_known_hosts
#RhostsRSAAuthentication no
# similar for protocol version 2
#HostbasedAuthentication no
# Change to yes if you don't trust ~/.ssh/known_hosts for
# RhostsRSAAuthentication and HostbasedAuthentication
#IgnoreUserKnownHosts no
# Don't read the user's ~/.rhosts and ~/.shosts files
#IgnoreRhosts yes
# To disable tunneled clear text passwords, change to no here!
#PasswordAuthentication yes
#PermitEmptyPasswords no
PasswordAuthentication yes
# Change to no to disable s/key passwords
#ChallengeResponseAuthentication yes
ChallengeResponseAuthentication no
# Kerberos options
#KerberosAuthentication no
#KerberosOrLocalPasswd yes
#KerberosTicketCleanup yes
#KerberosGetAFSToken no
# GSSAPI options
#GSSAPIAuthentication no
GSSAPIAuthentication yes
#GSSAPICleanupCredentials yes
GSSAPICleanupCredentials yes
# 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 mechanism.
# Depending on your PAM configuration, this may bypass the setting of
# PasswordAuthentication, PermitEmptyPasswords, and
# "PermitRootLogin without-password". If you just want the PAM account and
# session checks to run without PAM authentication, then enable this but set
# ChallengeResponseAuthentication=no
#UsePAM no
UsePAM yes
# Accept locale-related environment variables
AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES
AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT
AcceptEnv LC_IDENTIFICATION LC_ALL
#AllowTcpForwarding yes
#GatewayPorts no
#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
#X11UseLocalhost yes
#PrintMotd yes
#PrintLastLog yes
#TCPKeepAlive yes
#UseLogin no
#UsePrivilegeSeparation yes
#PermitUserEnvironment no
#Compression delayed
#ClientAliveInterval 0
#ClientAliveCountMax 3
#ShowPatchLevel no
#UseDNS yes
#PidFile /var/run/sshd.pid
#MaxStartups 10
#PermitTunnel no
#ChrootDirectory none
# no default banner path
#Banner /some/path
# override default of no subsystems
Subsystem sftp /usr/libexec/openssh/sftp-server
答案1
您可以使用一个简单的命令来验证它是否正在公共接口上监听这些端口。
netstat -tunelp | grep -i ssh
显然，您还需要确保远程计算机的出站端口 213 已打开，并且相关服务器的入站端口 213 已打开。远程计算机的 Nmap 将显示此信息
nmap -v -sT myremotehost.com -p 213
考虑到远程主机可能被阻止出站，而服务器可能阻止入站，因此这不是一门精确的科学。因此，禁用防火墙并使用排除法就足够简单了。
保存现有的 iptables 规则
iptables-save > /root/iptables.rules
清除现有规则
iptables -F
iptables -X
iptables -t nat -F
iptables -t nat -X
iptables -t mangle -F
iptables -t mangle -X
iptables -P INPUT ACCEPT
iptables -P FORWARD ACCEPT
iptables -P OUTPUT ACCEPT
然后运行测试。
然后恢复旧规则...
iptables-restore < /root/iptables.rules
请注意，我不赞成在生产机器上禁用防火墙。