[Mesh] batman-adv README

Miguel Vargas unroar at gmail.com
Fri May 17 15:26:28 PDT 2013


Hi guys,

Here is the README file I kept mentioning last night,
https://www.open-mesh.org/projects/batman-adv/repository/revisions/master/entry/README

It gives a simple explanation of batam-adv configuration without getting
into batctl, just the config files. The interesting piece is that you need
to provide an IP address to the bat0 interface.

The idea is that all the bat0 interfaces in the network together act like a
Layer 2 LAN. And just like a LAN you need to provide an IP address on the
same subnet to each interface in order for any packet routing to happen.
This is a problem for our idea of having a standard image that we can flash
onto all routers since each router will have to have individual
configuration.

The standard solution for assigning IP addresses in a network is to use
DHCP, but that is a problem because 1) we don't want any central control,
2) the network will probably end up being segmented into clusters that
don't talk to each other.

I was thinking one idea for assigning IP addresses could be to use IPv6 and
map the interface's MAC address onto it, we could then have a configuration
script to configure the address. But it turns out that this kind of thing
is built into the IPv6 protocol [1] . This seems to be what the Quickstart
guide is talking about when it says "You can now use the automatically
assigned IPv6 link-local adresses on bat0 (usually starting with
fe80::...), modern operating systems should support this." [2], although
when I followed the guide I didn't see any auto-configured IPv6 address.
I'm not very familiar with IPv6, I need to learn a lot more.

Another issue with batman-adv being a pure Layer 2 protocol is that there
needs to be some kind of Layer 3 routing protocol used on top of it in
order to direct packets to where they need to go. It turns out that
batman-adv has implemented such a thing as an optional 'gateway' feature.
The gateway documentation is interesting because it seems to show some of
the controversy generated around their philosophy of having a "clean
network layer separation" [3]. This gateway feature piggybacks on DHCP,
which has the problems I mentioned above.

Anyway, we need to keep reading and testing, there is a lot for us to
learn. It might be that we decide that batman-adv isn't the right choice
for the network we want to build, I think last night was great for getting
us towards making that decision. Though I think it's important for us to
develop a stronger vision for what it is that we do want to build.

Happy hacking.

[1]
http://en.wikipedia.org/wiki/IPv6_address#Stateless_address_autoconfiguration
[2] https://www.open-mesh.org/projects/batman-adv/wiki/Quick-start-guide
[3] http://www.open-mesh.org/projects/batman-adv/wiki/Gateways
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://sudoroom.org/lists/private/mesh/attachments/20130517/6a340dd9/attachment.html>


More information about the mesh mailing list