September 8, 2008

How do I disable the ping response?

Filed under: Fedora, linux, open source, Ubuntu, Uncategorized — Tags: — egoleo @ 3:37 pm

Usually a ping is used to check if a machine is up and to check the network status.

It is a small network packet sent to the machine. If the machine is up, an answer will be sent. The time needed to get the answer is called ping time or round-trip time.

The ping response from an IP indicates the machine is up.

Unfortunately this can be used to quickly scan an IP-range for reachable hosts.

This can be used to find potential hackable machines. If your machine doesn’t answer to pings, your chance to be seen is reduced. (That doesn’t mean your machine is more secure, the machine is just not that easy to be seen from the internet. Nothing more.)

Add the following line to your init script for the network (the name depends on the distribution you use):

echo 1 >/proc/sys/net/ipv4/icmp_echo_ignore_all

This disables ping responses.

To reenable, use the following command:

echo 0 >/proc/sys/net/ipv4/icmp_echo_ignore_all

To make this permanent set the following into /etc/sysctl.conf (if you have such a file)

net.ipv4.conf.icmp_echo_ignore_all = 1


February 22, 2007

Review of Fedora Core 6 Installation

Filed under: Fedora — Tags: — egoleo @ 7:50 am

After wondering in the world of ubuntu(debian), i decided to get into the world of fedora core specifically core 6. I was really happy with the looks. More over with the use YUM which makes it easier in updating and installing packages.My Desktop Screenshot

*** It seems Fedora made a error with the installation disc and mixed up i586 and i686 arches. To see if your installation got the error type this in the terminal as root user :***

rpm -q --qf='%{name}-%{version}-%{release}.%{arch}n' kernel
if the output says i586 then it indeed got the error and to fix this type this in the terminal :

su -c "yum install yum-utils"
yumdownloader kernel-2.6.18-1.2798.fc6.i686
su -c "rpm -Uvh --replacefiles --replacepkgs kernel-2.6.18-1.2798.fc6.i686.rpm"
yum update
And from this point, u can install all other stuffs

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