Make Secure OpenSSH Server On Ubuntu Server 14.10

Make Secure OpenSSH Server On Ubuntu Server 14.10

1. Login as root
2. Goto /etc/ssh folder
3. Run nano -c sshd_config

4.  Change default SSH port, example : "Port 3456"  

and then run to test ssh.

5.  Disable root access via SSH : PermitRootLogin no

6.  Disable password based authentication : PasswordAuthentication no

7.  Limit user SSH to access (Allow or Deny Users/Group):

     example:   

           1. for Allow user:  AllowUsers anony

           2. for Deny user :  DenyUsers anony

           3. for Allow group: AllowGroups marketing

           4. for Deny group : DenyGroups marketing

8. Restrict SSH on network interface

      ListenAddress 192.168.111.123

      ListenAddress 202.xxx.xxx.21

9. Set idle user time interval to avoid unattended ssh session.

      ClientAliveInterval 300
      ClientAliveCountMax 0

10. Disable Host-Based Authentication :    HostbasedAuthentication no

11. Disable .rhosts Files : IgnoreRhosts yes

AHS