OpenSSH
Remote operations are done using ssh, scp, and sftp.
Key management with ssh-add, ssh-keysign, ssh-keyscan, and ssh-keygen.
The service side consists of sshd, sftp-server, and ssh-agent.
基本用法 ssh root@ip
或 ssh -l root -p 22 ip
-l Specifies the user to log in as on the remote machine.
-p Port to connect to on the remote host.
-f Requests ssh to go to background just before command execution.
-C Requests compression of all data.
-N Do not execute a remote command. This is useful for just forwarding ports.
-R remote (server) host are to be forwarded to the local side.
-L local (client) host are to be forwarded to the given host and port, or Unix socket, on the remote side.
重启
1 2 3 service sshd restart 或 systemctl restart sshd
相关配置
1 grep -v '^\s*$\|^\s*\#' /etc/ssh/sshd_config
UsePrivilegeSeparation
连接慢
1 2 GSSAPIAuthentication no UseDNS no
修改端口
https://www.cyberciti.biz/faq/howto-change-ssh-port-on-linux-or-unix-server/
免密码登录
生成公钥
1 2 cd ~/.ssh ssh-keygen -t rsa
传输公钥至服务器
1 2 scp id_rsa.pub root@ip:~/.ssh cat id_rsa.pub >> authorized_keys
ssh-keyscan
1 ssh-keyscan -H -t rsa ip >> known_hosts
1 2 cat /var/run/sshd.pid kill $(cat /var/run/sshd.pid)
idle timeout for OpenSSH
端口转发 1 ssh -N -L*:80:localhost:9600 root@localhost
autossh 自动重连
主页 https://www.harding.motd.ca/autossh/ 文档 https://www.harding.motd.ca/autossh/README.txt
安装
1 2 Linux yum -y install autossh macOS brew install autossh
使用
1 2 3 4 autossh -M 10010 -N root@ip autossh -M 5122 -N -L2001:localhost:22 root@ip ssh root@127.0.0.1 -p 2001
https://stackoverflow.com/questions/25084288/keep-ssh-session-alive
ssh NAT traversal
1 2 3 4 5 6 7 ssh -N -R8887:localhost:8000 root@ip ssh root@ip ssh -N -L*:80:localhost:8887 root@localhost http://ip/ autossh -M 5122 -N -L2001:localhost:22 root@localhost ssh -N -L*:80:localhost:8887 root@localhost
sftp Compared to the SCP protocol, which only allows file transfers, the SFTP protocol allows for a range of operations on remote files which make it more like a remote file system protocol. An SFTP client’s extra capabilities include resuming interrupted transfers, directory listings, and remote file removal.
参考