ssh connection refused

ssh: connect to host localhost port 22: Connection refused

问题

在使用ssh连接时出现：

$ ssh localhost
ssh: connect to host localhost port 22: Connection refused

分析

SSH是否开启，端口是否监听

检查端口是否监听

$ ss -tnlp
State     Recv-Q      Send-Q            Local Address:Port             Peer Address:Port

从命令结果可以看到，SSH的监听端口(22)并没有

检查sshd.service服务是否开启

$ systemctl status sshd.service
● sshd.service - OpenSSH Daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled; vendor preset: disabled)
   Active: inactive (dead)

sshd.service没有没有激活

原因

ssh服务没有启动，端口未处于监听状态

解决

$ systemctl start sshd.service
$ systemctl status sshd.service
● sshd.service - OpenSSH Daemon
   Loaded: loaded (/usr/lib/systemd/system/sshd.service; disabled; vendor preset: disabled)
   Active: active (running) since Sun 2018-04-22 23:51:43 CST; 6s ago
 Main PID: 9429 (sshd)
    Tasks: 1 (limit: 4915)
   Memory: 1.7M
   CGroup: /system.slice/sshd.service
           └─9429 /usr/bin/sshd -D

4月 22 23:51:43 xiaoliu-manjaro systemd[1]: Started OpenSSH Daemon.
4月 22 23:51:43 xiaoliu-manjaro sshd[9429]: Server listening on 0.0.0.0 port 22.
4月 22 23:51:43 xiaoliu-manjaro sshd[9429]: Server listening on :: port 22.
$ ss -tmlp
State      Recv-Q      Send-Q            Local Address:Port            Peer Address:Port                                                                                                    
LISTEN     0           128                     0.0.0.0:ssh                  0.0.0.0:*         
     skmem:(r0,rb87380,t0,tb16384,f0,w0,o0,bl0,d0)                                              
LISTEN     0           128                        [::]:ssh                     [::]:*         
     skmem:(r0,rb87380,t0,tb16384,f0,w0,o0,bl0,d0)
$ ssh localhost
Last login: Sun Apr 22 17:22:36 2018 from ::1

附录

命令

• ss -tnlp
• systemctl status sshd.service
• systemctl start sshd.service
• ssh localhost

参考

• ArchWiki中Secure Shell章节: https://wiki.archlinux.org/index.php/OpenSSH