需求服务器是CEOS1.1需要配置telnet服务允许root通过telnet服务远程登录。本文这里使用systemd 直接管理 telnet。# 查看已安装的 telnet 相关包[rootlocalhost packages]# rpm -qa | grep telnettelnet-0.17-76.oe1.x86_64# 看看系统自带的 in.telnetd 在不在[rootlocalhost packages]# ls -l /usr/sbin/in.telnetd-rwxr-xr-x1root root570721月12022/usr/sbin/in.telnetd系统自带 in.telnetd 已经有了那就不需要再装 telnet-server 了。直接用系统自带的只创建 systemd 服务文件即可# 1. 创建 systemd socket 文件sudotee/etc/systemd/system/telnet.socketEOF [Unit] DescriptionTelnet Server Socket [Socket] ListenStream23 Acceptyes [Install] WantedBysockets.target EOF# 2. 创建 systemd service 文件sudotee/etc/systemd/system/telnet.serviceEOF [Unit] DescriptionTelnet Server Service [Service] ExecStart-/usr/sbin/in.telnetd StandardInputsocket StandardOutputsocket StandardErrorjournal EOF# 3. 加载并启动sudosystemctl daemon-reloadsudosystemctlenabletelnet.socketsudosystemctl start telnet.socket# 4. 放行 23 端口sudofirewall-cmd --add-port23/tcp--permanent2/dev/nullsudofirewall-cmd--reload2/dev/nullsudoiptables-IINPUT-ptcp--dport23-jACCEPT2/dev/null# 5. 允许 root 通过 telnet 登录sudosed-is/^auth[[:space:]]\required[[:space:]]\pam_securetty.so/#//etc/pam.d/remote# 6. 检查监听状态sudonetstat-tlnp|grep23[rootlocalhost packages]# sudo netstat -tlnp | grep 23tcp600:::23 :::* LISTEN1/systemd看到 LISTEN 后去笔记本测试cmd telnet 你的服务器IP出现 login: 就是通了输入 root 和密码。如果系统没有安装telnet还需要安装完整步骤如下cd/usr/local/src/packages# 1. 直接装 telnet忽略依赖sudorpm-ivhtelnet-server-0.17-65.el7_8.x86_64.rpm--nodepssudorpm-ivhtelnet-0.17-65.el7_8.x86_64.rpm--nodeps# 2. 创建 systemd socket 文件sudotee/etc/systemd/system/telnet.socketEOF [Unit] DescriptionTelnet Server Socket [Socket] ListenStream23 Acceptyes [Install] WantedBysockets.target EOF# 3. 创建 systemd service 文件sudotee/etc/systemd/system/telnet.serviceEOF [Unit] DescriptionTelnet Server Service [Service] ExecStart-/usr/sbin/in.telnetd StandardInputsocket StandardOutputsocket StandardErrorjournal EOF# 4. 加载并启动sudosystemctl daemon-reloadsudosystemctlenabletelnet.socketsudosystemctl start telnet.socket# 5. 放行 23 端口防火墙sudofirewall-cmd --add-port23/tcp--permanent2/dev/nullsudofirewall-cmd--reload2/dev/nullsudoiptables-IINPUT-ptcp--dport23-jACCEPT2/dev/null# 6. 允许 root 登录sudosed-is/^auth[[:space:]]\required[[:space:]]\pam_securetty.so/#//etc/pam.d/remote# 7. 检查监听状态sudonetstat-tlnp|grep23