1 .. SPDX-License-Identifier: GPL-2.0
7 Batman advanced is a new approach to wireless networking which does no longer
8 operate on the IP basis. Unlike the batman daemon, which exchanges information
9 using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI
10 Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It
11 emulates a virtual network switch of all nodes participating. Therefore all
12 nodes appear to be link local, thus all higher operating protocols won't be
13 affected by any changes within the network. You can run almost any protocol
14 above batman advanced, prominent examples are: IPv4, IPv6, DHCP, IPX.
16 Batman advanced was implemented as a Linux kernel driver to reduce the overhead
17 to a minimum. It does not depend on any (other) network driver, and can be used
18 on wifi as well as ethernet lan, vpn, etc ... (anything with ethernet-style
25 Load the batman-adv module into your kernel::
27 $ insmod batman-adv.ko
29 The module is now waiting for activation. You must add some interfaces on which
30 batman can operate. After loading the module batman advanced will scan your
31 systems interfaces to search for compatible interfaces. Once found, it will
32 create subfolders in the ``/sys`` directories of each supported interface,
35 $ ls /sys/class/net/eth0/batman_adv/
36 elp_interval iface_status mesh_iface throughput_override
38 If an interface does not have the ``batman_adv`` subfolder, it probably is not
39 supported. Not supported interfaces are: loopback, non-ethernet and batman's
42 Note: After the module was loaded it will continuously watch for new
43 interfaces to verify the compatibility. There is no need to reload the module
44 if you plug your USB wifi adapter into your machine after batman advanced was
47 The batman-adv soft-interface can be created using the iproute2 tool ``ip``::
49 $ ip link add name bat0 type batadv
51 To activate a given interface simply attach it to the ``bat0`` interface::
53 $ ip link set dev eth0 master bat0
55 Repeat this step for all interfaces you wish to add. Now batman starts
56 using/broadcasting on this/these interface(s).
58 By reading the "iface_status" file you can check its status::
60 $ cat /sys/class/net/eth0/batman_adv/iface_status
63 To deactivate an interface you have to detach it from the "bat0" interface::
65 $ ip link set dev eth0 nomaster
68 All mesh wide settings can be found in batman's own interface folder::
70 $ ls /sys/class/net/bat0/mesh/
71 aggregated_ogms fragmentation isolation_mark routing_algo
72 ap_isolation gw_bandwidth log_level vlan0
73 bonding gw_mode multicast_mode
74 bridge_loop_avoidance gw_sel_class network_coding
75 distributed_arp_table hop_penalty orig_interval
77 Some files allow to change batman-adv's behaviour to better fit your
78 requirements. For instance, you can check the current originator interval (value
79 in milliseconds which determines how often batman sends its broadcast packets)::
81 $ cat /sys/class/net/bat0/mesh/orig_interval
84 and also change its value::
86 $ echo 3000 > /sys/class/net/bat0/mesh/orig_interval
88 In very mobile scenarios, you might want to adjust the originator interval to a
89 lower value. This will make the mesh more responsive to topology changes, but
90 will also increase the overhead.
92 Information about the current state can be accessed via the batadv generic
93 netlink family. batctl provides human readable version via its debug tables
100 To make use of your newly created mesh, batman advanced provides a new
101 interface "bat0" which you should use from this point on. All interfaces added
102 to batman advanced are not relevant any longer because batman handles them for
103 you. Basically, one "hands over" the data by using the batman interface and
104 batman will make sure it reaches its destination.
106 The "bat0" interface can be used like any other regular interface. It needs an
107 IP address which can be either statically configured or dynamically (by using
108 DHCP or similar services)::
110 NodeA: ip link set up dev bat0
111 NodeA: ip addr add 192.168.0.1/24 dev bat0
113 NodeB: ip link set up dev bat0
114 NodeB: ip addr add 192.168.0.2/24 dev bat0
115 NodeB: ping 192.168.0.1
117 Note: In order to avoid problems remove all IP addresses previously assigned to
118 interfaces now used by batman advanced, e.g.::
120 $ ip addr flush dev eth0
126 All error messages, warnings and information messages are sent to the kernel
127 log. Depending on your operating system distribution this can be read in one of
128 a number of ways. Try using the commands: ``dmesg``, ``logread``, or looking in
129 the files ``/var/log/kern.log`` or ``/var/log/syslog``. All batman-adv messages
130 are prefixed with "batman-adv:" So to see just these messages try::
132 $ dmesg | grep batman-adv
134 When investigating problems with your mesh network, it is sometimes necessary to
135 see more detail debug messages. This must be enabled when compiling the
136 batman-adv module. When building batman-adv as part of kernel, use "make
137 menuconfig" and enable the option ``B.A.T.M.A.N. debugging``
138 (``CONFIG_BATMAN_ADV_DEBUG=y``).
140 Those additional debug messages can be accessed using the perf infrastructure::
142 $ trace-cmd stream -e batadv:batadv_dbg
144 The additional debug output is by default disabled. It can be enabled during
145 run time. Following log_levels are defined:
150 - All debug output disabled
152 - Enable messages related to routing / flooding / broadcasting
154 - Enable messages related to route added / changed / deleted
156 - Enable messages related to translation table operations
158 - Enable messages related to bridge loop avoidance
160 - Enable messages related to DAT, ARP snooping and parsing
162 - Enable messages related to network coding
164 - Enable messages related to multicast
166 - Enable messages related to throughput meter
168 - Enable all messages
170 The debug output can be changed at runtime using the file
171 ``/sys/class/net/bat0/mesh/log_level``. e.g.::
173 $ echo 6 > /sys/class/net/bat0/mesh/log_level
175 will enable debug messages for when routes change.
177 Counters for different types of packets entering and leaving the batman-adv
178 module are available through ethtool::
180 $ ethtool --statistics bat0
186 As batman advanced operates on layer 2, all hosts participating in the virtual
187 switch are completely transparent for all protocols above layer 2. Therefore
188 the common diagnosis tools do not work as expected. To overcome these problems,
189 batctl was created. At the moment the batctl contains ping, traceroute, tcpdump
190 and interfaces to the kernel module settings.
192 For more information, please see the manpage (``man batctl``).
194 batctl is available on https://www.open-mesh.org/
200 Please send us comments, experiences, questions, anything :)
203 #batman on irc.freenode.org
205 b.a.t.m.a.n@open-mesh.org (optional subscription at
206 https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
208 You can also contact the Authors:
210 * Marek Lindner <mareklindner@neomailbox.ch>
211 * Simon Wunderlich <sw@simonwunderlich.de>