Setting up a gateway on Linux

There are a few different ways to run an AMPRnet gateway on a Linux system. Each has some benefits, so you'll need to pick your favourite.

Before configuring the Linux gateway you'll need to follow the common instructions for setting up a gateway: Obtain your AMPRnet 44/8 IP addresses from a regional coordinator, obtain a public static IP address for your gateway, insert your gateway in the Gateways database using the Portal and get some of your 44.* IP addresses registered in the ampr.org DNS.

Flavours of Linux gateways

Native Linux kernel AX.25 and IPIP tunneling

Linux contains the necessary building blocks for a gateway without much added software. Radio interfaces are configured much like any other network interfaces such as Ethernet, they're just given amateur radio callsigns in addition to an IP address (callsign will act the role of the Ethernet MAC address). If you're familiar with Linux configuration but have not heard of NOS, or if you wish to go with minimal amount of moving parts, this would probably be your choice.

Setting up a native Linux gateway consists of two main steps:

Setting up tunnel routing to the rest of the AMPRnet

1. Automatically Learning about other tunnel endpoints via modified RIPv2 advertisements. Two popular programs to do this are:
   1. Using amprripd, a C based routing daemon
   2. Using rip44d, a PERL based routing daemon
2. Manually Downloading the encap.txt file using FTP and setting up routes using a munge script is the traditional method

Example Gateway Configuration Instructions

• Ubuntu Linux Gateway Example

Setting up radio interfaces in Linux

• Linux AX.25 set-up
• 802.11 WiFi on amateur frequencies (2.4 or 5 GHz) is a new popular way to set up fast links

Running JNOS (or other NOS) on top of Linux

If you're already familiar with running NOS on top of DOS or Linux, or wish to keep the AMPRnet IP packet routing away from the host Linux system, it might make sense to run JNOS as an application on top of Linux.

The downside is that it'll have a slightly higher overhead (consumed memory and CPU), and you'll have two IP routers running on top of each other instead of just one, which is seen as slightly complicated by some.

The upside is that you'll also get the JNOS BBS-type features, and some other traditional services without installing additional software on top.

John Martin KF8KK has written a Linux - Jnos Setup and Configuration HOW-TO.