Configuration¶

Load the batman-adv module into your kernel:

$ insmod batman-adv.ko

The module is now waiting for activation. You must add some interfaces on whichbatman-adv can operate. The batman-adv soft-interface can be created using theiproute2 toolip:

$ ip link add name bat0 type batadv

To activate a given interface simply attach it to thebat0 interface:

$ ip link set dev eth0 master bat0

Repeat this step for all interfaces you wish to add. Now batman-adv startsusing/broadcasting on this/these interface(s).

To deactivate an interface you have to detach it from the “bat0” interface:

$ ip link set dev eth0 nomaster

The same can also be done using the batctl interface subcommand:

batctl -m bat0 interface createbatctl -m bat0 interface add -M eth0

To detach eth0 and destroy bat0:

batctl -m bat0 interface del -M eth0batctl -m bat0 interface destroy

There are additional settings for each batadv mesh interface, vlan and hardifwhich can be modified using batctl. Detailed information about this can be foundin its manual.

For instance, you can check the current originator interval (valuein milliseconds which determines how often batman-adv sends its broadcastpackets):

$ batctl -M bat0 orig_interval1000

and also change its value:

$ batctl -M bat0 orig_interval 3000

In very mobile scenarios, you might want to adjust the originator interval to alower value. This will make the mesh more responsive to topology changes, butwill also increase the overhead.

Information about the current state can be accessed via the batadv genericnetlink family. batctl provides a human readable version via its debug tablessubcommands.

Usage¶

To make use of your newly created mesh, batman advanced provides a newinterface “bat0” which you should use from this point on. All interfaces addedto batman advanced are not relevant any longer because batman handles them foryou. Basically, one “hands over” the data by using the batman interface andbatman will make sure it reaches its destination.

The “bat0” interface can be used like any other regular interface. It needs anIP address which can be either statically configured or dynamically (by usingDHCP or similar services):

NodeA: ip link set up dev bat0NodeA: ip addr add 192.168.0.1/24 dev bat0NodeB: ip link set up dev bat0NodeB: ip addr add 192.168.0.2/24 dev bat0NodeB: ping 192.168.0.1

Note: In order to avoid problems remove all IP addresses previously assigned tointerfaces now used by batman advanced, e.g.:

$ ip addr flush dev eth0

Logging/Debugging¶

All error messages, warnings and information messages are sent to the kernellog. Depending on your operating system distribution this can be read in one ofa number of ways. Try using the commands:dmesg,logread, or looking inthe files/var/log/kern.log or/var/log/syslog. All batman-adv messagesare prefixed with “batman-adv:” So to see just these messages try:

$ dmesg | grep batman-adv

When investigating problems with your mesh network, it is sometimes necessary tosee more detailed debug messages. This must be enabled when compiling thebatman-adv module. When building batman-adv as part of the kernel, use “makemenuconfig” and enable the optionB.A.T.M.A.N.debugging(CONFIG_BATMAN_ADV_DEBUG=y).

Those additional debug messages can be accessed using the perf infrastructure:

$ trace-cmd stream -e batadv:batadv_dbg

The additional debug output is by default disabled. It can be enabled duringrun time:

$ batctl -m bat0 loglevel routes tt

will enable debug messages for when routes and translation table entries change.

Counters for different types of packets entering and leaving the batman-advmodule are available through ethtool:

$ ethtool --statistics bat0

batctl¶

As batman advanced operates on layer 2, all hosts participating in the virtualswitch are completely transparent for all protocols above layer 2. Thereforethe common diagnosis tools do not work as expected. To overcome these problems,batctl was created. At the moment the batctl contains ping, traceroute, tcpdumpand interfaces to the kernel module settings.

For more information, please see the manpage (manbatctl).

batctl is available onhttps://www.open-mesh.org/

Contact¶

Please send us comments, experiences, questions, anything :)

IRC:

#batman on irc.freenode.org

Mailing-list:

b.a.t.m.a.n@open-mesh.org (optional subscription athttps://lists.open-mesh.org/mailman3/postorius/lists/b.a.t.m.a.n.lists.open-mesh.org/)

You can also contact the Authors:

• Marek Lindner <mareklindner@neomailbox.ch>
• Simon Wunderlich <sw@simonwunderlich.de>