ATCOM Mesh Potato, User Manual

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SECN User Guide
to access the MPs for management in this configuration, it is necessary to configure a PC with a
static address in the same range as the MPs, and attach via Ethernet cable or WiFi.
The default IP address assigned to the
br-lan interface in the MPs is 10.130.1.20 which is unlikely
to conflict with the default address range of commodity routers.
If it is desired to have the MPs appear on the LAN, the
br-lan IP address should be assigned
accordingly during set up.
The address assigned to the
br-lan interface for each MP must be changed to be unique, so that each
device can provide a separate telephone number. This IP address assignment may be made by a
number of methods including telephone IVR, web interface or manipulation of the
/etc/config/network file.
5.2 Batman-Advanced Operation
Batman-advanced is a "OSI layer 2" routing protocol which is implemented as a kernel module in
the Linux kernel. Since Linux 2.6.38 batman-advanced is an official part of Linux.
When you assign at least one active physical network interface to batman-advanced, it will create
the virtual
bat0 interface. In the SECN firmware ath0 is assigned to the batman-advanced kernel
module. ath0 is the wireless interface operating in multipoint-to-multipoint mode (ad-hoc).
Because batman-advanced operates entirely on MAC layer (OSI layer 2), ath0 doesn't need any
Layer 3 configuration. Only its Layer 2 MAC address is required. The MAC address is configured
during production, so we don't need to configure it. All we need to do is make sure to switch
ath0 on. To sum it up: ath0 is the link-local transport interface for the batman-advanced mesh.
Batman-adv itself bridges all bat0 interfaces in all the mesh devices to a big, smart, virtual switch.
This means that all bat0 interfaces in the mesh are link-local - even if they are multiple wireless
hops away.
Despite being virtual,
bat0 acts like a real, physical, network interface connected to a big switch. As
such you can run all kinds of network protocols on it, like IPv4, IPv6, ARP, Zeroconf (yes, you can
run mDNS on
bat0 !), IPX – or whatever protocol that can communicate over a network interface
that is connected link local (which means directly connected, like a straight Ethernet cable
connected between two computers, or a bunch of computers connected to a switch).
In the SECN firmware the
bat0 interface itself is again assigned (or rather enslaved) to a bridge in
each machine. bat0 is part of the bridge named br-lan , together with ath1 and eth0 .
eth0 is the LAN port of the MP. ath1 is a access-point interface, operating as a master in WiFi
infrastructure mode. (As opposed to a infrastructure client, like laptops or smartphones with a WiFi
interface).
Hence
all eth0 and ath1 interfaces in all devices running the SECN firmware are part of one big
wireless bridge. The ath0 interface does the low level work to carry the traffic link-locally from hop
to hop and batman-advanced takes care about the routes that the MAC packets have to take.
Note: It is not possible to add IP settings to an interface which is encapsulated in a bridge - you can
only assign IP settings to the bridge interface itself. eth0 is part of the bridge br-lan, together with
ath1 , bat0 (the batman-advanced virtual interface, which is routed by the mesh routing protocol on
MAC level). Hence you can not assign any IP settings to eth0 , ath1 or bat0 - only to br-lan .
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