1
vote
4answers
62 views

Securing debain with fail2ban or iptables

I'm looking to secure my server. Initially my first thought was to use iptables but then I also learnt about Fail2ban. I understand that Fail2ban is based on iptables, but it has the advantages of ...
2
votes
1answer
65 views

fail2ban with PermitRootLogin without-password?

I tried to choose a title that cover the topic: Why should I use fail2ban (or similar programs) if I've my PermitRootLogin set to without-password? A very trusted and experienced sysadmin that I ...
0
votes
1answer
155 views

How to unban from fail2ban?

fail2ban banned my ip for SSH. In email I received that said I got banned via fail2ban after 5 attempts against SSH. Which is not even truth i wasn't even loging to SSH. I can still access webmin. I ...
0
votes
0answers
49 views

Using fail2ban for auth.log POSSIBLE BREAK-IN ATTEMPT!s when on VPN

I've been getting a bunch of reverse mapping checking getaddrinfo for some-long-domain.example.com [X.X.X.X] failed - POSSIBLE BREAK-IN ATTEMPT! on my personal server. It's not as if these ...
2
votes
4answers
246 views

Protect ssh server

I've got a debian-machine running several services, like apache with http and https, jabber and an openssh server for administration. The ssh-server is not running on port 22. It's on something like ...
0
votes
1answer
119 views

fail2ban block retry count always changes

As title mentions clearly, fail2ban block retry count always changes. I set all retry counts to 3; but sometimes it blocks me after 6 or 7 retries. How can set its behavior a constant value? I added ...
2
votes
3answers
2k views

fail2ban iptables having port 22 and fails to block ssh on custom port

This question is almost same problem like mine but accepted answer doesn't solve my issues In Fail2Ban, How to Change the SSH port number? SSH on port 22 everything works great. After 5 attempts ...
1
vote
2answers
294 views

Is there any reason to use fail2ban with SSH password logins disabled?

I am setting up an Ubuntu server hosted by Linode. I am stepping through their security guide and they recommend installing fail2ban after disabling password based SSH logins. I don't see the point ...
4
votes
4answers
7k views

In Fail2Ban, How to Change the SSH port number?

In my server, the ssh port is not the standard 22. I have set a different one. If I setup fail2ban, will it be able to detect that port? How can I tell it to check that port rather than port 22? The ...
1
vote
3answers
510 views

Firewalls (ufw vs apf) on Ubuntu

On my LAMP servers, do either of the firewall interfaces (ufw or apt) allow you to setup rate limiting to automatically ban brute force attempts (e.g. via SSH)? Or, is it best to install fail2ban in ...
2
votes
2answers
2k views

Fail2Ban - how to prevent my ISP IP dynamic get banned?

I have just installed Fail2Ban. I want to add my ISP IP to my ignore list but my IP is dynamic. In the jail.conf file, I have like this: [DEFAULT] # "ignoreip" can be an IP address, a CIDR mask or ...
0
votes
2answers
288 views

SSH Authentication - Bruteforce attack prevention

I use certificate/key based ssh authentication with sshd running on non standard port. Do I still need to install denyhosts/fail2ban or log analysis based detection?. Do I get any advantage?
0
votes
1answer
144 views

Fail2ban Custom Port

I have a rule like this in my jail.local file: [ssh-ddos] enabled = true port = ssh,sftp filter = sshd-ddos logpath = /var/log/messages maxretry = 4 If I want to use a custom port for SSH, ...
0
votes
1answer
282 views

fail2ban Service Crashing

I have a miss behaving fail2ban service on a very much live server. It'll tally up to 100% cpu usage after boot for about 30min then goes down to a stable 0.1% It freakin me out, something is crashing ...
2
votes
3answers
583 views

fail2ban bans me after a series of *successful* logins

I created a passwordless ssh login for one of my servers by using the authorized_keys file. The server has fail2ban on it, and I noticed that after several successful logins I could no longer log in ...
6
votes
5answers
3k views

Is it worth the effort to block failed login attempts

Is it worthwhile running fail2ban, sshdfilter or similar tools, which blacklist IP addresses which attempt and fail to login? I've seen it argued that this is security theatre on a "properly ...
1
vote
2answers
239 views

SSHD logs events in the future

I'm setting up a small VPS (last Centos) and I'm facing a problem with my SSHD logs. I want to install fail2ban and everything seems to run fine, but I noticed a lot of attempts of bruteforce in the ...
8
votes
5answers
1k views

is fail2ban safe? Better to use ssh keys?

I'm in doubt if I should use key authentication when logging into SSH, or just go for fail2ban + ssh (root login disabled). Is fail2ban safe or is it really better to just go ahead and generate keys ...
4
votes
6answers
3k views

fail2ban and denyhosts constantly ban me on Ubuntu

I just got an Ubuntu instance on Linode. To secure the SSH on it, I installed fail2ban (using apt-get), but then had a problem: fail2ban kept banning my IP (for limited durations, thankfully) even ...