Rahul Sahu

To forward emails received by a Postfix mail server to another email account, follow these steps: Edit the Postfix configuration file /etc/postfix/main.cf: # vi /etc/postfix/main.cf Add the following line to the end of the file to specify the email address to which emails should be forwarded: virtual_alias_maps = hash:/etc/postfix/virtual Create a new file /etc/postfix/virtual and … Read more

OpenNTPD is a free and easy-to-use implementation of the Network Time Protocol (NTP) that provides accurate time synchronization between servers and clients on a network. Here are the steps to install OpenNTPD on FreeBSD: Update the package repository: # pkg update Install OpenNTPD: # pkg install openntpd Edit the configuration file /etc/ntpd.conf to specify the … Read more

Keychain is a utility that manages SSH keys in a convenient and secure way. It can be used to set up secure passwordless SSH access for backup scripts on Linux. Here are the steps to use keychain to achieve this: Install keychain on your Linux system. On Debian/Ubuntu, you can use the following command: sudo … Read more

In FreeBSD, you can disable the hardware bell, also known as the system beep, by setting the hw.syscons.bell parameter to 0. This parameter can be set in the /boot/loader.conf file, which is read during the boot process. Here are the steps to disable the hardware beep in FreeBSD: Open a terminal window or SSH into … Read more

TCP Wrappers is a security feature in Unix-based systems that provides access control and authentication for network services. TCP Wrappers allow you to specify which hosts or networks are allowed to connect to your services, and which services they are allowed to use. You can find out if a program is compiled with TCP Wrappers … Read more

Fedora 11 is a very old version of Fedora and is no longer supported. Upgrading from Fedora 11 to a newer version is not recommended, as it is likely to result in compatibility issues and other problems. If you are currently running Fedora 11 and want to upgrade to a newer version, the recommended approach … Read more

There are several command line tools you can use to identify the operating system and applications running on a remote host. Here are a few options: nmap: nmap is a powerful network exploration tool that can be used to identify the operating system and applications running on a remote host. To run a basic OS … Read more

The dump command in Unix/Linux is used to backup and restore file systems. You can exclude certain directories or files from a dump using the exclude option. Here’s how to do it: dump -0u -f /path/to/backup-file /filesystem/to/backup -X /path/to/exclude-file Here, the -X option is used to specify a file that lists directories or files to … Read more

FreeBSD jails are a lightweight virtualization technology that allow you to create multiple isolated environments on a single host. Ezjail is a popular utility that makes it easier to create and manage jails on FreeBSD. Here’s how you can set up FreeBSD jails with ezjail: Install ezjail: pkg install ezjail Create a base jail: ezjail-admin … Read more

If you have installed a new binary on your Linux or BSD system and the shell doesn’t recognize it, it’s likely because the binary is not in your system’s PATH. Here’s how you can add the directory containing the binary to the PATH: Determine the directory that contains the binary. For example, if you installed … Read more