Just some advice to make your SSH server more secure:
* Use private not public keys with strong passwords
* Do not allow root login to the SSH server
* Don't use the default port 22 but choose one of the high order ports
* Use a port knocker to hide your SSH port (install and configure: knockd)
* Configure your iptables to allow only certain addressees (only if you connect from static places for example your work or home)
* Also configure your /etc/hosts.deny and /etc/hosts.allow for sshd
* Use fail2ban to defend yourself from bruteforce attacks
* Use fwsnort to have SNORT rules in your iptables which will protect you against exploits for example. You do need to configure this: fwsnort --update-rules && fwsnort
Then run the sh script in /etc/fwsnort and save your iptables with for example: iptables-persistent
* Use and configure PSAD for port scan protection
* Only allow certain users to connect to the SSH deamon
If you need more detail on any of these tips then just ask and I'll provide ;-)
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Met vriendelijke groet,
Kees de Jong
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