OpenSSH security

[savook]

I would really appreciate, if someone answer to below questions.

1. How to tell sshd (or the firewall) to ban ip address after -let's say- 3 failed attempts.

2. How can I allow remote user to connect to the server only one connection per time.

3. How can I allow ssh root login from perticular host.

Thanks & regards
Savook

[b2bwild]

try this command once.

man ssh_config

[proopnarine]

1. How to tell sshd (or the firewall) to ban ip address after -let's say- 3 failed attempts.

Try installing denyhost.

[b2bwild]

denyhost, is good option but fail2ban is better, it supports ssh, vsftpd and apache.