Re:How to Protect Your Infrastructure Against the Basic Atta...
by mordechai9000 on Wednesday January 06, 2016 @02:01PM
(#10852732)
I like to use a limit rule (ufw limit 22/tcp) for SSH, to discourage brute force attacks. If nothing else, it will help reduce the noise in the log files.
This isn't a replacement for basic precautions such as disabling root login and not allowing password authentication, of course.
ufw comes pre-installed on ubuntu and is dead simple to use, there's really no reason not to use it.
should be all you need to have connection tracking on both v6 and v4, have a tried and trusted icmpv6 accept list, and keep your v6 and v4 firewalls in sync.