Zack Weinberg on Nostr: 6. fail2ban is most definitely worth it, but other firewalling has a good chance of ...

6. fail2ban is most definitely worth it, but other firewalling has a good chance of being more trouble than it's worth. In particular, I wouldn't bother with dropping instead of rejecting SYNs to closed ports, and I'm dubious about firewalling by port number. (About the only thing that's good for, IMO, is putting an extra speed bump in front of an adversary who already has remote execution and wants to persist it.)