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How website valuation actually works, what traffic estimates can and cannot tell you, and which once-standard metrics have quietly stopped existing.
Postfix mail for domain.com loops back to myself Error and Solution
The "mail for domain.com loops back to myself" error occurs when a mail server is configured to accept email for a domain it is responsible for but is unable to deliver it to the correct recipient. This usually happens because the DNS MX record for the domain points to the server itself. To fix t
BIND: Max open files (1024) is smaller than max sockets (4096) Error and Solution
When running the BIND (Berkeley Internet Name Domain) DNS server on a Linux or Unix-based system, you may encounter the following error message:rn rn rn max open files ( 1024 ) is smaller than max sockets ( 4096 )rn rn rnThis error message indicates that the maximum number of open files allowed by t
Upgrade FreeBSD 7.x to 7.2 Stable Release
Upgrading from FreeBSD 7.x to 7.2 Stable Release involves performing a source upgrade. Here are the steps to upgrade from FreeBSD 7.x to 7.2:rn rn Before starting the upgrade process, it is recommended to back up important data and configurations. This will help you recover in case anything goes wro
CentOS Linux Install zlib-devel RPM Package
The zlib-devel RPM package contains the development libraries and header files for the zlib library. These files are required to compile programs that use the zlib library. Here's how to install the zlib-devel RPM package on CentOS:rn rn Open a terminal window on your CentOS system. rn Install the y
SPAMHAUS BLOCKLIST ADDRESS IS WRONG MUST FIX Error and Solution
The "SPAMHAUS BLOCKLIST ADDRESS IS WRONG MUST FIX" error usually occurs when there is an incorrect or outdated IP address in the Spamhaus blocklist configuration file. This can cause legitimate email messages to be blocked by the email server. Here's how to fix the issue:rn rn Edit the Spamhaus b
Tunneling X Connection Through Intermediate Linux / BSD Gateway
Tunneling an X connection through an intermediate Linux/BSD gateway involves forwarding X11 protocol packets over SSH connections, so that the display of the remote X application can be displayed on the local X server. Here are the steps to set up tunneling of X connections:rn rn Connect to the i
FreeBSD Move /usr or /var File System To Another Hard Disk
In FreeBSD, it is possible to move the /usr or /var file systems to another hard disk. The steps below will guide you through the process: n n Backup the contents of the /usr or /var file system to the new hard disk. You can use rsync for this purpose:n n n sudo rsync -avz /usr /mnt/new_disk n n n I
FreeBSD Jail Allow Ping / tracerouter Commands
To allow ping and traceroute commands inside a FreeBSD jail, you will need to modify the jail's configuration to allow ICMP traffic.rn rn Edit the jail's configuration file:rn rn rn sudo vi /etc/jail.confrn rn rn Add the following line to the configuration file, replacing jail_name with the name of
Red Hat / CentOS Install mod_security Apache Intrusion Detection And Prevention Engine
To install and configure mod_security on Red Hat or CentOS, you can follow these steps:rn rn Install the mod_security package using yum :rn rn rn sudo yum install mod_securityrn rn rn After installation, the mod_security module is enabled by default. You can edit the mod_security.conf file to custom
Gracefully Restart Lighttpd Web Server
To gracefully restart the Lighttpd web server, you can use the lighttpd command with the -s option and the graceful-restart argument. Here's the command you can use:rn rn rn sudo lighttpd -s graceful-restartrn rn rnWhen you run this command, Lighttpd will reload its configuration and gracefully r
HowTo: Skip Bash For Loop
In Bash, you can skip a for loop iteration using the continue keyword. Here's an example:rn rn rn #!/bin/bash for i in {1..10}rn do rn if ]; then rn continue rn fi echo "Iteration $i " rn done rn rn rnIn this example, we have a for loop that iterates from 1 to 10. Inside the loop, we have
OpenSuse Linux: How to Read Logs or Log Files
In openSUSE Linux, you can use various commands to read and analyze logs or log files. Here are some of the most commonly used commands:rn rn less : This command allows you to view the contents of a log file and navigate through it. For example, to view the /var/log/messages file, you can run:rn rn
Awk Print Line After A Matching /regex/
To print the line after a pattern match in awk , you can use a flag variable to keep track of whether the current line matches the pattern, and print the next line if the flag is set. Here's an example: Suppose we have a file called data.txt with the following content:rn rn rn applernbananarnc
Reset PF Firewall Automatically While Testing Configuration With Remote Server Over SSH Session
If you are testing PF firewall configuration on a remote server over an SSH session, it is important to have a way to automatically reset the firewall in case something goes wrong and you lose your connection to the server. One way to do this is to use a script that runs periodically and resets the
How to use yum-cron to automatically update RHEL/CentOS Linux
Yum-cron is a package that can be used to automatically update packages on RHEL/CentOS Linux systems. Here are the steps to set up yum-cron:rn rn Install yum-cron:rn rn rn sudo yum install yum-cronrn rn rn Edit the configuration file for yum-cron:rn rn rn sudo vi /etc/yum/yum-cron.confrn rn rnThe co
Debian / Ubuntu Linux Install Advanced Intrusion Detection Environment (AIDE) Software
AIDE (Advanced Intrusion Detection Environment) is a popular and powerful tool for monitoring file system changes on a Linux system. It can be used to detect and alert on any unauthorized changes to files, directories, and other system objects. Here are the steps to install and configure AIDE on Deb
How to run crontab job every minute on a Linux or Unix-like system
To run a crontab job every minute on a Linux or Unix-like system, you can use the following syntax:rn rn rn * * * * * command- to -be-executedrn rn rnThis will run the command-to-be-executed every minute of every hour of every day of the week. Here's a breakdown of what each * represents:rn rn *
Linux Tune Network Stack (Buffers Size) To Increase Networking Performance
The networking performance of a Linux system can be improved by tuning the network stack buffers sizes. The buffer sizes can be adjusted using the sysctl command. Here are the steps to tune the network stack buffers size:rn rn Open a terminal or shell prompt on your Linux system. rn Verify that t
How To Verify SSL Certificate From A Shell Prompt
You can verify an SSL certificate from a shell prompt using the openssl command-line tool. Here's how to do it:rn rn Open a terminal or shell prompt on your Linux or Unix system. rn Run the following command to check the SSL certificate of a website:rn rn rn openssl s_client - connect example.com: 4
Linux Limit CPU Usage Per Process
In Linux, you can limit the CPU usage of a process by using the cpulimit command. Here's how to use it:rn rn Install cpulimit on your Linux system, if it is not already installed. You can do this using your distribution's package manager. For example, on Ubuntu or Debian, you can run:rn rn rn sudo a
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