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

Installing OpenSSH

Our first option for remote access is the simplest, assuming that you just need to be able to remotely access a shell on your Linux system. All Linux distributions offer the ability to install a Secure Shell (SSH) server. The most common SSH server available is OpenSSH, which is distributed by the OpenBSD team. A lighter weight option called Dropbear is also available and is often found in embedded Linux platforms, such as OpenWRT.

How to do it…

Installing OpenSSH on a Linux system is very easy but the specifics on how to do it will depend on the Linux distribution that you are using.

Let's install SSH server in Debian/Ubuntu through the following command:

# sudo apt-get install ssh

For Fedora, CentOS, and other RedHat derivatives, it would be sudo yum install openssh-server.

Now, once OpenSSH is installed, anyone with network access to tcp port 22 on your system may attempt to log in to your system. If this machine is your firewall or if you forward port 22 from your firewall...