03 Mar 2010 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 just select Disable Rule in the last step.
These steps does also work in Windows 7 to enable ping.
Tags: firewall, Windows 7, Windows Server 2008 R2
Posted by Hans-Henry Jakobsen
05 Sep 2007 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 a whitelist of IP addresses which are allowed to access your server. The advantage of this setup is that you can grant the machine you are using access to the ports on your server dynamically without having to reconfigure your firewall or access list.
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Posted by Hans-Henry Jakobsen
08 May 2007 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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Tags: firewall, iptables, ssh, syslog
Posted by Hans-Henry Jakobsen
18 Apr 2007 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
Tags: Fedora, firewall, iptables
Posted by Hans-Henry Jakobsen
