Category Archives: Linux

Articles for Linux

iptables port forwarding

iptables port forwarding I am port forwarding  public ip x.x.x.x  to private ip 192.168.200.200  . iptables -A INPUT -i eth0 -p tcp –dport 5001 -m state –state NEW,ESTABLISHED -j ACCEPT iptables -A OUTPUT -o eth0 -p tcp –sport 5001 -m … Continue reading

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how to configure Static IP on Centos 6

how to configure Static IP on Centos 6 ## Configure eth0 # # vi /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=”eth0″ NM_CONTROLLED=”yes” ONBOOT=yes HWADDR=A4:BA:DB:37:F1:04 TYPE=Ethernet BOOTPROTO=static NAME=”System eth0″ UUID=5fb06bd0-0bb0-7ffb-45f1-d6edd65f3e03 IPADDR=192.168.1.44 NETMASK=255.255.255.0

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How to Show All NAT Tables Rules IPTABLES

How to Show All NAT Tables Rules IPTABLES iptables -t nat -L iptables -t nat -L -n -v | grep ‘something’ iptables -t nat -L -n -v The netstat-nat command display the natted connections on a Linux iptable firewall yum … Continue reading

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no “setup” command found in CentOS minimal install

no “setup” command found in CentOS minimal install In Minimum Install this will not get install If we got below Error, we need to install some packages to get work with setup command [root@gkhan.in ~] setup -bash: setup: command not … Continue reading

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fail2ban missing whois program

fail2ban missing whois program missing whois program in fail2ban email alerts . you are not able to receive IP information . #yum search whois gnome-nettool.x86_64 : A GNOME interface for various networking tools jwhois.x86_64 : Internet whois/nicname client. perl-Net-Whois.noarch : … Continue reading

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How to Install the noip Client on Linux

How to Install the noip Client on Linux noip  provides free Dynamic DNS services  ( http://www.noip.com/remote-access) as DynDns was providing but its allow only three hostnames as free. This guide will walk you through the installation and setup of the … Continue reading

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Remote Host Identification Has Changed error and solution

Remote Host Identification Has Changed error and solution When we run scp command  to copy data to remote host its gives us error @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ @ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @ @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@ IT IS POSSIBLE THAT SOMEONE IS DOING … Continue reading

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How to search text in linux

How to search text in linux You can use grep command in Linux  for example grep -Ril “text-to-find-here” / i stands for upper/lower case (optional in your case). R stands for recursive. l stands for “show the file name, not … Continue reading

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how to run multiple command on single line on CentOS

If you want to run multiple command on single line on CentOS. If you want to execute each command only if the previous one succeeded, then combine them using the  “&&” operator. If one of the commands fails, then all … Continue reading

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