1.. SPDX-License-Identifier: GPL-2.0
2
3==========
4batman-adv
5==========
6
7Batman advanced is a new approach to wireless networking which does no longer
8operate on the IP basis. Unlike the batman daemon, which exchanges information
9using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI
10Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It
11emulates a virtual network switch of all nodes participating. Therefore all
12nodes appear to be link local, thus all higher operating protocols won't be
13affected by any changes within the network. You can run almost any protocol
14above batman advanced, prominent examples are: IPv4, IPv6, DHCP, IPX.
15
16Batman advanced was implemented as a Linux kernel driver to reduce the overhead
17to a minimum. It does not depend on any (other) network driver, and can be used
18on wifi as well as ethernet lan, vpn, etc ... (anything with ethernet-style
19layer 2).
20
21
22Configuration
23=============
24
25Load the batman-adv module into your kernel::
26
27  $ insmod batman-adv.ko
28
29The module is now waiting for activation. You must add some interfaces on which
30batman-adv can operate. The batman-adv soft-interface can be created using the
31iproute2 tool ``ip``::
32
33  $ ip link add name bat0 type batadv
34
35To activate a given interface simply attach it to the ``bat0`` interface::
36
37  $ ip link set dev eth0 master bat0
38
39Repeat this step for all interfaces you wish to add. Now batman-adv starts
40using/broadcasting on this/these interface(s).
41
42To deactivate an interface you have to detach it from the "bat0" interface::
43
44  $ ip link set dev eth0 nomaster
45
46The same can also be done using the batctl interface subcommand::
47
48  batctl -m bat0 interface create
49  batctl -m bat0 interface add -M eth0
50
51To detach eth0 and destroy bat0::
52
53  batctl -m bat0 interface del -M eth0
54  batctl -m bat0 interface destroy
55
56There are additional settings for each batadv mesh interface, vlan and hardif
57which can be modified using batctl. Detailed information about this can be found
58in its manual.
59
60For instance, you can check the current originator interval (value
61in milliseconds which determines how often batman-adv sends its broadcast
62packets)::
63
64  $ batctl -M bat0 orig_interval
65  1000
66
67and also change its value::
68
69  $ batctl -M bat0 orig_interval 3000
70
71In very mobile scenarios, you might want to adjust the originator interval to a
72lower value. This will make the mesh more responsive to topology changes, but
73will also increase the overhead.
74
75Information about the current state can be accessed via the batadv generic
76netlink family. batctl provides a human readable version via its debug tables
77subcommands.
78
79
80Usage
81=====
82
83To make use of your newly created mesh, batman advanced provides a new
84interface "bat0" which you should use from this point on. All interfaces added
85to batman advanced are not relevant any longer because batman handles them for
86you. Basically, one "hands over" the data by using the batman interface and
87batman will make sure it reaches its destination.
88
89The "bat0" interface can be used like any other regular interface. It needs an
90IP address which can be either statically configured or dynamically (by using
91DHCP or similar services)::
92
93  NodeA: ip link set up dev bat0
94  NodeA: ip addr add 192.168.0.1/24 dev bat0
95
96  NodeB: ip link set up dev bat0
97  NodeB: ip addr add 192.168.0.2/24 dev bat0
98  NodeB: ping 192.168.0.1
99
100Note: In order to avoid problems remove all IP addresses previously assigned to
101interfaces now used by batman advanced, e.g.::
102
103  $ ip addr flush dev eth0
104
105
106Logging/Debugging
107=================
108
109All error messages, warnings and information messages are sent to the kernel
110log. Depending on your operating system distribution this can be read in one of
111a number of ways. Try using the commands: ``dmesg``, ``logread``, or looking in
112the files ``/var/log/kern.log`` or ``/var/log/syslog``. All batman-adv messages
113are prefixed with "batman-adv:" So to see just these messages try::
114
115  $ dmesg | grep batman-adv
116
117When investigating problems with your mesh network, it is sometimes necessary to
118see more detailed debug messages. This must be enabled when compiling the
119batman-adv module. When building batman-adv as part of the kernel, use "make
120menuconfig" and enable the option ``B.A.T.M.A.N. debugging``
121(``CONFIG_BATMAN_ADV_DEBUG=y``).
122
123Those additional debug messages can be accessed using the perf infrastructure::
124
125  $ trace-cmd stream -e batadv:batadv_dbg
126
127The additional debug output is by default disabled. It can be enabled during
128run time::
129
130  $ batctl -m bat0 loglevel routes tt
131
132will enable debug messages for when routes and translation table entries change.
133
134Counters for different types of packets entering and leaving the batman-adv
135module are available through ethtool::
136
137  $ ethtool --statistics bat0
138
139
140batctl
141======
142
143As batman advanced operates on layer 2, all hosts participating in the virtual
144switch are completely transparent for all protocols above layer 2. Therefore
145the common diagnosis tools do not work as expected. To overcome these problems,
146batctl was created. At the moment the batctl contains ping, traceroute, tcpdump
147and interfaces to the kernel module settings.
148
149For more information, please see the manpage (``man batctl``).
150
151batctl is available on https://www.open-mesh.org/
152
153
154Contact
155=======
156
157Please send us comments, experiences, questions, anything :)
158
159IRC:
160  #batman on irc.freenode.org
161Mailing-list:
162  b.a.t.m.a.n@open-mesh.org (optional subscription at
163  https://lists.open-mesh.org/mailman3/postorius/lists/b.a.t.m.a.n.lists.open-mesh.org/)
164
165You can also contact the Authors:
166
167* Marek Lindner <mareklindner@neomailbox.ch>
168* Simon Wunderlich <sw@simonwunderlich.de>
169