Novasredes

Redes de computadores experimentais

802.11s FC's TrunkServ Reticulum Yggdrasil network

This is a part of yggdrasil

Written by: Tristan Brice Velloza Kildaire

This is a guide on how to create you own Yggdrasil node.

Prerequisites

Before we get started it is important that you take a look at first reading the setup process of a 802.11s node. The important parts to take note of there are those pertaining to the wifi radio and wifi interface configuration parameters specific to the Yggdrasil experiment WiFi network.

Specific

For the wifi-iface declared within this document pertaining to client access, you may use any band and channel and even SSID that you want. That’s your personal choice.

We do recommend you name it something like Novasredes (N: Y, T: CLIENT) but maybe something more basic and human readable would help.

Yggdrasil - the tree network

Before we can begin configuring anything we first need to install support for the Yggdrasil routing protocol. This is done by installing the yggdrasil package with:

opkg install yggdrasil

We will also want the ability to perform configuration via UCI and have support for a new interface type known as yggdrasil, therefore we install the luci-proto-yggdrasil package:

opkg install luci-proto-yggdrasil

Note: I had to reboot for the new protocol type to appear usable. I checked via LuCi just to confirm. Also thanks to this guy’s post for pointing it out.

Generate some keys

Before we continue we need to generate both our private key and our public key. We can do both of these via the yggdrasil command.

The way I go about generating a private key is to generate a temporary configuration file in /tmp/ygg.conf with and from which I then grab the private key:

yggdrasil -genconf > /tmp/f.txt # generate new private key in config file
head /tmp/f.txt # get top of config file

Then to derive the public key you need to use the -publickey option and tell Yggdrasil which config file to use for obtaining the private key to derive from:

yggdrasil -useconffile /tmp/f.txt -publickey # derive public key
rm /tmp/f.txt # delete the config file

Configuring an interface

We’ll now create our ygg0 interface which will provide our OpenWrt host with access to the Yggdrasil network. We name the interface entry ygg0 as follows:

config interface 'ygg0'
	option proto 'yggdrasil'
    
	option private_key '<private key>'
	option public_key '<public key>'
	option node_info '{"name": "caldeira-map2", "contact": "deavmi@redxen.eu"}'
    
	list listen_address 'tcp://[::]:2000'
	list listen_address 'tls://[::]:2001'

A few things to note:

  1. the interface entry’s name, ygg0, is what the name of the TUN adaptor will be
  2. the private_key and public_key options must contain your private and public key pair
  3. the node_info option allows you to place arbitrary JSON that can be requested by other nodes on the network via a node info request. a. It is convention to always fill in the "name" and "contact" fields with string-typed values as these allow you to be named on the Yggdrasil map and the contact information makes it easy for others to get a-hold of you
  4. the list listen_address can be appear multiple times and is for configuring the addresses you want to listen on for incoming peering connections (not from local discovery) if any

Configuring beaconing and listening

We can also configure, as a seperate yggdrasil entry, what Ethernet interfaces we should ahve Ygdrasil peform link-local IPv6 multiocvast router discovery on.

The yggdrasil entry must be named as yggdrasil_ygg0_interface or more generally as yggdrasil_<InterfaceNameHere>_interface and will look something like this:

config yggdrasil_ygg0_interface
	list interface 'eth1'
	option beacon '1'
	option listen '1'

Some things to note:

One more thing to note, if you want to have different beaconing and listening policies for different interfaces then simply define another yggdrasil entry - and yes, the name must be the same (a duplicate)

In fact we do want to do this. I want to also have link-local multicast discovery happening over the mesh0 interface - that’s the whole point remember! Let’s add another yggdrasil interface for that with:

config yggdrasil_ygg0_interface
	list interface 'mesh0'
	option beacon '1'
	option listen '1'

Configuring Internet peers

I want to configure an uplink to the wider Yggdrasil network, we do this with a peer entry named in the form of yggdrasil_<InterfaceNameHere>_peer or in our case as yggdrasil_ygg0_peer which looks as follows:

config yggdrasil_ygg0_peer
	option address 'tls://[::1]:2112'

You may also define multiple peer entries but the name must be the same:

config yggdrasil_ygg0_peer
	option address 'tls://sto01.yggdrasil.hosted-by.skhron.eu:8884'

config yggdrasil_ygg0_peer
	option address 'tls://yggdrasil.deavmi.assigned.network:2001'

Note Running service network reload doesn’t seem to do it for yggdrasil, rather a restart is needed with service network restart.

Other things

Just some other items that may be of use to you for maintenance reasons.

Installation of packages script

This script removes and installs all that is needed:

#!/bin/sh
opkg remove wpad-basic-mbedtls
opkg install yggdrasil luci-proto-yggdrasil wpad-mesh-mbedtls nano

Updating script

In order to make applying updates for all currently installed packages that may have a new version you can run this script:

#!/bin/sh
opkg update
for i in $(opkg list-upgradable | cut -d" " -f1)
do
	opkg upgrade $i
done

Advisory notes

24.10.4 and 24.10.1 differences

Next steps?

That is enough to help join the Yggdrasil network and help route traffic. The next step would be allowing people to optionally access Yggdrasil via your node.

For information on client access read this guide.