Month: September 2013

  • How to use IPTABLES

    To Drop IP in iptables Port Specific: iptables -A INPUT -p tcp -s xx.xx.xx.xx –dport {PORT} -j DROP iptables -A INPUT -p tcp -s xx.xx.xx.xx –dport 80 -j DROP /sbin/service iptables save No Port Specified: iptables -A INPUT -s xx.xx.xx.xx -j DROP /sbin/service iptables save Example: /sbin/iptables -I INPUT -s {IP-HERE} -j DROP /sbin/iptables -I…

  • Boot Repair

    Boot-Repair is a simple tool to repair frequent boot issues you may encounter in Ubuntu like when you can’t boot Ubuntu after installing Windows or another Linux distribution, or when you can’t boot Windows after installing Ubuntu, or when GRUB is not displayed anymore, some upgrade breaks GRUB, etc. Boot-Repair lets you fix these issues…

  • Setting timezone and synchronizing time with NTP

    Check available timezones in your server by executing the command below. ls /usr/share/zoneinfo/ Then simply delete the current timezone: rm /etc/localtime Create a symbolic link to /etc/localtime. ln –s /usr/share/zoneinfo/Asia/Singapore /etc/localtime If symblolic link not working, then you may use a copy command. cp /usr/share/zoneinfo/Asia/Singapore /etc/localtime Install NTP yum install ntp See all the timezones…

  • How to enable port 587 (submission) in postfix

    To enable port 587, edit the file /etc/postfix/master.cf vi /etc/postfix/master.cf and remove the # in front of the line: #submission inet n – n – – smtpd so that it looks like this: submission inet n – n – – smtpd and restart postfix: /etc/init.d/postfix restart