Windows

Enable or disable ping in Windows Server 2008 R2

I always forget where to change the ping setting in the Windows Server 2008 R2 Firewall. To enable ping Go to Start >> Administrative Tools >> Windows Firewall with Advanced Security >> Inbound Rules >> File and Printer Sharing (Echo Request – ICMPv4-IN) >> right click and select Enable Rule. To disable the ping rule […]

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Security

Port Knocking

What is Port Knocking? Port knocking is a method by which you can dynamically open ports on your server to a single IP address. Port knocking allows you to transparently run a service on your server without exposing the services of that port to all IP addresses. In practice, it is very similar to having […]

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Scripting

SSH Dictionary Attack Prevention with iptables

It is ideal to slow down the SSH dictionary attack when the infested host started to brute force the SSH authentication. There are many scripts/user-land daemons that perform monitoring and blocking. I prefer to use something that has less demand in memory/CPU usage. IPTables module provides a kernel level solution with little overhead.

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Security

Open a range of ports with iptables

In RedHat/Fedora you can define firewall rules in the file /etc/sysconfig/iptables. By adding this line you open ports in the range 5920-5960 -A RH-Firewall-1-INPUT -p tcp –destination-port 5920:5960 -j ACCEPT

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