Ubuntu Linux Gateway Example

From 44Net Wiki
Revision as of 23:43, 29 March 2014 by Njohnson (talk | contribs)
Jump to navigation Jump to search

The following are the steps necessary to create a general purpose gateway to AMPRNet using an Ubuntu Linux Server.

Not everyone needs a gateway!

You only need to setup a gateway if:

  • You want to access AMPRNet resources that are not accessible from the Global Internet.
  • You want to provide access to AMPRNet over RF (via packet or using WiFi).

Design

The basic design consists of a standard PC running Ubuntu 12.04 (LTS) and three network connections:

  1. The first connection is to your ISP so you can reach the Internet.
  2. The second connection is used to connect your normal "non-ham" devices to the Internet.
  3. The third connection is used to connect your "ham" devices so they can see and be seen by other AMPRNet devices.

The following diagram shows the layout of the connections. (Click on the image to enlarge).

Error creating thumbnail: File missing

Prerequisites

Hardware

I'm running an old Dell Optiplex GX260 (a Pentium 4 with 512 MB of RAM and a 20 GB Hard drive). You don't need much if your Internet Service Provider's bandwidth is 100Mb/s or less.

Along with the built in Ethernet network interface, I've installed two additional 10/100 Ethernet network cards I purchased from Amazon.

Software

On the Dell I've installed Ubuntu 12.04 LTS (the 32-bit server version).

IP Addresses

What is an IPv4 Address ?

An IPv4 address is a unique 32-bit binary number that is assigned to every publicly connected Internet device.

To make the address easy for humans to read, it is usually represented as a four decimal numbers separated by periods (i.e. 192.0.0.2)

More information on IPv4 address can be found here

Static IPv4 from your ISP

What is a Static IP ?

Normally your ISP assigns you an IP address dynamically from a pool of IP addresses.

Private IPv4 Addresses for "Non-Ham" Devices

AMPRNet IPv4 Address Allocation

Installing Required Software

Setting up the ISP (Internet) Interface

Configuring the interface

Testing

Setting up the "Non-Ham" Network Interface

Configuring the Interface

Setting up Routing (Part 1)

Setting up DNS

Setting up DHCP

Testing

Setting up the Firewall (Part 1)

Setting up NAT

Protecting the Gateway

Protecting the "Non-Ham" Network

Saving the firewall rules

Setting up the Local "Ham" Network (AMPRNet) Interface

Configuring the Interface

More DHCP

Setting up the Tunnel to AMPRNet

Setting up Routing (Part 2)

Setting up Policy Based Routing

Automating Routing Updates with rip44d

Getting rip44d

Compiling and installing rip44d

Running rip44d

Setting up the Firewall (Part 2)

Projecting the Local "Ham" Network

Testing

Saving your work

Next Steps