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
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Using OpenSSH to forward defined ports


One extremely useful piece of functionality is the ability to forward ports from the remote system to your local system or vice versa.

How to do it…

  • Forward a remote port locally: –L 8000:192.168.1.123:80

  • Forward a local port remotely: –R 5000:localhost:22

  • Make either port available from remote systems with –g

How it works…

The –L option allows you to make a remote port available locally. The arguments are [bind_address:]port:host:hostport.

In our example, we're logging into a remote system and then forwarding port 80 on 192.168.1.123 of your local system. This means that if you connect your web browser to localhost port 8000, you will actually be hitting the server on 192.168.1.123. This is useful for accessing resources behind a firewall or just changing the network your connection is established from. Note that if you're specifically using this for a web server, you may need to play tricks with your host files or ports in use in order to work around...