Mesh Node HOWTO

Following are instructions to set up a mesh-networking node in Debian. This guide assumes Debian Stable, jessie or later. If you are unsure of which release of Debian you are using, try the command lsb_release -a

This is a step-by-step guide to help in understanding the process. If you want easy deployment, see http://libre-mesh.org/howitworks.html, OpenWRT, or other projects that will be listed here.

Set up hardware

First you will need to verify that your radio supports mesh mode or IBSS mode. These two modes are the new version of what used to be called "Repeater" and "Ad Hoc" modes. No mode called "Ad Hoc" exists any more in the

iw

tool.

iwconfig

in Jessie still supports Ad-Hoc mode. https://wireless.wiki.kernel.org/en/users/drivers uses the mesh / IBSS terminology, so this guide will standardize on that.

The difference between the two modes

https://wireless.wiki.kernel.org/en/users/documentation/modes

From the

iwconfig

man page:

             The mode can be Ad-Hoc (network composed of only
             one cell and without Access Point), Managed (node connects to  a
             network  composed  of  many Access Points, with roaming), Master
             (the node is the synchronisation master or  acts  as  an  Access
             Point),  Repeater (the node forwards packets between other wire‐
             less  nodes),  Secondary  (the  node  acts  as  a  backup   mas‐
             ter/repeater), Monitor (the node is not associated with any cell
             and passively monitor all packets on the frequency) or Auto.

Firmware

Once you have verified that your radio hardware supports the requisite mode, you must ensure that the correct firmware is installed to make it work properly. Some radios will still work with limited functionality without the correct firmware file installed, which can be confusing.

Kernel module / driver

https://wireless.wiki.kernel.org/en/users/drivers contains a list and feature matrix of available kernel modules.

Of course, your system should detect and use the correct kernel module on its own; use

lsmod

to check once you have verified the correct chipset ID of the radio hardware using lspci / lsusb as appropriate.

Choosing and installing a mesh routing program

https://android.googlesource.com/kernel/common/+/android-trusty-3.10/net/batman-adv/

cjdns

CJDNS is an all-in-one networking stack authored mostly (entirely?) by Caleb James Delisle (cjd, not to be confused with [djb]). It offers a host of excellent features such as end-to-end encryption, zeroconf, and other nice things. It has a strange build system (nodejs - based, but not one of the existing node libs for this purpose) and can be difficult in deployment. Joining a cjdns mesh requires interaction with a human being to acquire a key. To my knowledge cjdns is not packaged for any Linux distribution.

olsrd

Optimized Link State Routing Daemon is packaged in Debian.

https://packages.debian.org/search?suite=jessie&searchon=names&keywords=olsrd

Babel

Babel is the routing protocol developed by HacDC's Byzantium project.

BATMAN

Better Approach to Mobile Ad-Hoc Networking is a project related in some way to FreiFunk.

https://www.open-mesh.org/projects/batmand/wiki/Faq

BATMAN works only with ipv4 and has other limitations, which is why batman-adv exists.

batmand

Resources

https://manpages.debian.org/cgi-bin/man.cgi?query=batmand
https://www.open-mesh.org/projects/batmand/wiki/InternetTuning - managing and announcing Internet gateways on your BATMAN network

batgat

From the BATMAN FAQ: What is the batgat kernel module good for?

The batman daemon maintains a tunnel connection to every "batman internet client". Every packet that goes to the internet or comes back has to go through this tunnel. As it is a user space tunnel a lot of copying between user space and kernel land is necessary. Depending on the number of clients and the CPU power available this might be a bottleneck. The batgat kernel module tries to overcome this limitation. Once loaded the batman daemon will detect its presence automatically on startup. The daemon will activate the kernel module to let it handle the tunneling, hence avoiding the expensive copy operations. There is no difference between the daemon tunneling and the kernel tunneling other than that.