From the category archives:

Networking

Determine the autonegotiated ethernet connection speed and duplex using the mii-tool command. Running the following command as superuser with no options will generate basic information about all of the ethernet interfaces on the computer: [[email protected] ~]# mii-tool

{ 0 comments }

How to find the default gateway on Linux

by lifeLinux on May 2, 2011

Whether you are troubleshooting network problems or trying to set up a VPN…, knowing what address your computer has configured as the default gateway is always useful. Running a simple command from the terminal can give you this. [email protected]:~# route -n Sample outputs: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface […]

{ 0 comments }

How to disable ICMP echo responses in Linux

by lifeLinux on May 2, 2011

Many malicious attacks begin with a ping scan. Disabling ICMP echo requests prevents your system’s discovery with a ping. Disable ICMP echo responses temporarily You can temporarily disable the ICMP using the following method but this setting will be erased after the reboot. [email protected]:~# echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all

{ 0 comments }

How to install IPTables on RedHat / Centos Linux

by lifeLinux on April 24, 2011

iptables is a user space application program that allows a system administrator to configure the tables provided by the Linux kernel firewall (implemented as different Netfilter modules) and the chains and rules it stores. Different kernel modules and programs are currently used for different protocols; iptables applies to IPv4, ip6tables to IPv6, arptables to ARP, […]

{ 1 comment }

Anti SYN Flood with IPTables

by lifeLinux on April 21, 2011

#!/bin/sh # A simple shell to build a Firewall anti SYN Flood # Under CentOS, Fedora and RHEL / Redhat Enterprise Linux # servers. # —————————————————————————- # Written by LongVNIT # (c) 2009 lifeLinux under GNU GPL v2.0+ IPT=”iptables” MODPROBE=”modprobe” IF=”eth0″ IP=”192.168.1.112″ PORT=”22 80 443″ CHECK_TIME=60 BAN_TIME=120 HITCOUNT=10 MOD=”ip_tables ip_conntrack iptable_filter ipt_state” # Load Module […]

{ 1 comment }

Load balancing helps provide redundancy to your website. However, one often asked question is how to keep your content synchronized on each server. If you put a new web page on one server, how does it get copied over to the second server? In this article, i’ll explain how to use rsync command to synchronize […]

{ 0 comments }