Information Security Management: prevents SSH password retry tool software. read Information Security Management: prevents SSH password retry tool software. Fail2ban can be used by the system.
Fail2ban can use the built-in firewall, such as Linux iptables or FreeBSD ipfw, and can be used with tcpd. In addition, it can be extended to other network services, currently, I mainly use monitoring port 22 and/var/log/secure logs, mainly for those logs with illegal access. When an IP address is found in a defined period of time, if an SSH password attempt fails to reach a defined number of times, the LINUX iptables can be used to prevent the IP address from being modified for a defined period of time. of course, you can also disable it without a deadline.
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Download the fail2ban-0.6.2-1brn.src.rpm, because the 0.6.1 version has time to judge the BUG, and the use of source code re-compilation can be more with the actual system environment, to achieve the best performance, so... the source code package of the selected version.
Rpmbuild -- rebuild fail2ban-0.6.2-1brn.src.rpm
From the compilation log we can know that the compiled RPM in/usr/src/redhat/RPMS/noarch/fail2ban-0.6.2-1brn.noarch.rpm
Rpm-Uvh/usr/src/redhat/RPMS/noarch/fail2ban-0.6.2-1brn.noarch.rpm
The execution file is already in/etc/init. d/fail2ban. as a service, you can use service fail2ban {start | stop | status | restart | condrestart} for operations.
The configuration file is in/etc/fail2ban. conf.
The default configuration is to monitor SSH ports and logs, so I have not made any major changes. if you are interested, you can try to monitor the logs and ports of other services.
I changed several parameters:
"Locale =" is changed to "locale = en_US", which is mainly used for time format matching. the BUG in version 0.6.1 does not have this parameter, which makes it unavailable after installation, 0.6.2 is installed normally.
"Maxfailures = 3", which is actually the maximum number of attempts. if the time range defined later exceeds the number of attempts, IP addresses are blocked from accessing the SSH port.
"Bantime = 3600" is actually a blocking period. when the blocking condition is reached, the IP address is blocked from accessing the SSH port for 3600 seconds, the document says that if "-1" is set to permanent blocking, you can set it as needed.
"Findtime = 60", this parameter is the time period of the attempt. in this time period, determine the number of previous attempts. When this parameter is reached, it will prevent other parameters from being moved. wait for time to study again.
The startup method is very simple, so I won't talk about it here.