Book Image

Linux Networking Cookbook

By : Agnello Dsouza, Gregory Boyce
5 (1)
Book Image

Linux Networking Cookbook

5 (1)
By: Agnello Dsouza, Gregory Boyce

Overview of this book

Linux can be configured as a networked workstation, a DNS server, a mail server, a firewall, a gateway router, and many other things. These are all part of administration tasks, hence network administration is one of the main tasks of Linux system administration. By knowing how to configure system network interfaces in a reliable and optimal manner, Linux administrators can deploy and configure several network services including file, web, mail, and servers while working in large enterprise environments. Starting with a simple Linux router that passes traffic between two private networks, you will see how to enable NAT on the router in order to allow Internet access from the network, and will also enable DHCP on the network to ease configuration of client systems. You will then move on to configuring your own DNS server on your local network using bind9 and tying it into your DHCP server to allow automatic configuration of local hostnames. You will then future enable your network by setting up IPv6 via tunnel providers. Moving on, we’ll configure Samba to centralize authentication for your network services; we will also configure Linux client to leverage it for authentication, and set up a RADIUS server that uses the directory server for authentication. Toward the end, you will have a network with a number of services running on it, and will implement monitoring in order to detect problems as they occur.
Table of Contents (19 chapters)
Linux Networking Cookbook
About the Author
About the Reviewer

Monitoring via NRPE

As I mentioned earlier, a number of plugins, such as check_memory, collect information from the system itself, which means that they cannot be directly used for monitoring remote systems. As these are often critical things to monitor, there are ways available to indirectly collect that information from remote systems using the Nagios Remote Plugin Executer (NRPE).

NRPE runs on the machine that you'd like to monitor and executes the same commands/plugins which Nagios itself would have. Nagios is then configured to collect data from NRPE rather than collecting data directly.

How to do it…

  1. Install nrpe on your monitoring target:

    sudo apt-get install nagios-nrpe-server
  2. Restrict access to the NRPE service:

    sed -i 's|allowed_hosts=.*|allowed_hosts=|g' /etc/nagios/nrpe.cfg
  3. Define any additional checks to run by adding them into /etc/nagios/nrpe.cfg:

  4. Configure your nagios server to collect data via nrpe by creating...