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1[state: 21-11-2010]
2
3BATMAN-ADV
4----------
5
6Batman advanced is a new approach to wireless networking which
7does no longer operate on the IP basis. Unlike the batman daemon,
8which exchanges information using UDP packets and sets routing
9tables, batman-advanced operates on ISO/OSI Layer 2 only and uses
10and routes (or better: bridges) Ethernet Frames. It emulates a
11virtual network switch of all nodes participating. Therefore all
12nodes appear to be link local, thus all higher operating proto-
13cols won't be affected by any changes within the network. You can
14run almost any protocol above batman advanced, prominent examples
15are: IPv4, IPv6, DHCP, IPX.
16
17Batman advanced was implemented as a Linux kernel driver to re-
18duce the overhead to a minimum. It does not depend on any (other)
19network driver, and can be used on wifi as well as ethernet lan,
20vpn, etc ... (anything with ethernet-style layer 2).
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 in-
30terfaces on which batman can operate. After loading the module
31batman advanced will scan your systems interfaces to search for
32compatible interfaces. Once found, it will create subfolders in
33the /sys directories of each supported interface, e.g.
34
35# ls /sys/class/net/eth0/batman_adv/
36# iface_status mesh_iface
37
38If an interface does not have the "batman_adv" subfolder it prob-
39ably is not supported. Not supported interfaces are: loopback,
40non-ethernet and batman's own interfaces.
41
42Note: After the module was loaded it will continuously watch for
43new interfaces to verify the compatibility. There is no need to
44reload the module if you plug your USB wifi adapter into your ma-
45chine after batman advanced was initially loaded.
46
47To activate a given interface simply write "bat0" into its
48"mesh_iface" file inside the batman_adv subfolder:
49
50# echo bat0 > /sys/class/net/eth0/batman_adv/mesh_iface
51
52Repeat this step for all interfaces you wish to add. Now batman
53starts using/broadcasting on this/these interface(s).
54
55By reading the "iface_status" file you can check its status:
56
57# cat /sys/class/net/eth0/batman_adv/iface_status
58# active
59
60To deactivate an interface you have to write "none" into its
61"mesh_iface" file:
62
63# echo none > /sys/class/net/eth0/batman_adv/mesh_iface
64
65
66All mesh wide settings can be found in batman's own interface
67folder:
68
69# ls /sys/class/net/bat0/mesh/
70# aggregated_ogms bonding fragmentation orig_interval
71# vis_mode
72
73
74There is a special folder for debugging informations:
75
76# ls /sys/kernel/debug/batman_adv/bat0/
77# originators socket transtable_global transtable_local
78# vis_data
79
80
81Some of the files contain all sort of status information regard-
82ing the mesh network. For example, you can view the table of
83originators (mesh participants) with:
84
85# cat /sys/kernel/debug/batman_adv/bat0/originators
86
87Other files allow to change batman's behaviour to better fit your
88requirements. For instance, you can check the current originator
89interval (value in milliseconds which determines how often batman
90sends its broadcast packets):
91
92# cat /sys/class/net/bat0/mesh/orig_interval
93# 1000
94
95and also change its value:
96
97# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
98
99In very mobile scenarios, you might want to adjust the originator
100interval to a lower value. This will make the mesh more respon-
101sive to topology changes, but will also increase the overhead.
102
103
104USAGE
105-----
106
107To make use of your newly created mesh, batman advanced provides
108a new interface "bat0" which you should use from this point on.
109All interfaces added to batman advanced are not relevant any
110longer because batman handles them for you. Basically, one "hands
111over" the data by using the batman interface and batman will make
112sure it reaches its destination.
113
114The "bat0" interface can be used like any other regular inter-
115face. It needs an IP address which can be either statically con-
116figured or dynamically (by using DHCP or similar services):
117
118# NodeA: ifconfig bat0 192.168.0.1
119# NodeB: ifconfig bat0 192.168.0.2
120# NodeB: ping 192.168.0.1
121
122Note: In order to avoid problems remove all IP addresses previ-
123ously assigned to interfaces now used by batman advanced, e.g.
124
125# ifconfig eth0 0.0.0.0
126
127
128VISUALIZATION
129-------------
130
131If you want topology visualization, at least one mesh node must
132be configured as VIS-server:
133
134# echo "server" > /sys/class/net/bat0/mesh/vis_mode
135
136Each node is either configured as "server" or as "client" (de-
137fault: "client"). Clients send their topology data to the server
138next to them, and server synchronize with other servers. If there
139is no server configured (default) within the mesh, no topology
140information will be transmitted. With these "synchronizing
141servers", there can be 1 or more vis servers sharing the same (or
142at least very similar) data.
143
144When configured as server, you can get a topology snapshot of
145your mesh:
146
147# cat /sys/kernel/debug/batman_adv/bat0/vis_data
148
149This raw output is intended to be easily parsable and convertable
150with other tools. Have a look at the batctl README if you want a
151vis output in dot or json format for instance and how those out-
152puts could then be visualised in an image.
153
154The raw format consists of comma separated values per entry where
155each entry is giving information about a certain source inter-
156face. Each entry can/has to have the following values:
157-> "mac" - mac address of an originator's source interface
158 (each line begins with it)
159-> "TQ mac value" - src mac's link quality towards mac address
160 of a neighbor originator's interface which
161 is being used for routing
162-> "HNA mac" - HNA announced by source mac
163-> "PRIMARY" - this is a primary interface
164-> "SEC mac" - secondary mac address of source
165 (requires preceding PRIMARY)
166
167The TQ value has a range from 4 to 255 with 255 being the best.
168The HNA entries are showing which hosts are connected to the mesh
169via bat0 or being bridged into the mesh network. The PRIMARY/SEC
170values are only applied on primary interfaces
171
172
173LOGGING/DEBUGGING
174-----------------
175
176All error messages, warnings and information messages are sent to
177the kernel log. Depending on your operating system distribution
178this can be read in one of a number of ways. Try using the com-
179mands: dmesg, logread, or looking in the files /var/log/kern.log
180or /var/log/syslog. All batman-adv messages are prefixed with
181"batman-adv:" So to see just these messages try
182
183# dmesg | grep batman-adv
184
185When investigating problems with your mesh network it is some-
186times necessary to see more detail debug messages. This must be
187enabled when compiling the batman-adv module. When building bat-
188man-adv as part of kernel, use "make menuconfig" and enable the
189option "B.A.T.M.A.N. debugging".
190
191Those additional debug messages can be accessed using a special
192file in debugfs
193
194# cat /sys/kernel/debug/batman_adv/bat0/log
195
196The additional debug output is by default disabled. It can be en-
197abled during run time. Following log_levels are defined:
198
1990 - All debug output disabled
2001 - Enable messages related to routing / flooding / broadcasting
2012 - Enable route or hna added / changed / deleted
2023 - Enable all messages
203
204The debug output can be changed at runtime using the file
205/sys/class/net/bat0/mesh/log_level. e.g.
206
207# echo 2 > /sys/class/net/bat0/mesh/log_level
208
209will enable debug messages for when routes or HNAs change.
210
211
212BATCTL
213------
214
215As batman advanced operates on layer 2 all hosts participating in
216the virtual switch are completely transparent for all protocols
217above layer 2. Therefore the common diagnosis tools do not work
218as expected. To overcome these problems batctl was created. At
219the moment the batctl contains ping, traceroute, tcpdump and
220interfaces to the kernel module settings.
221
222For more information, please see the manpage (man batctl).
223
224batctl is available on http://www.open-mesh.org/
225
226
227CONTACT
228-------
229
230Please send us comments, experiences, questions, anything :)
231
232IRC: #batman on irc.freenode.org
233Mailing-list: b.a.t.m.a.n@b.a.t.m.a.n@lists.open-mesh.org
234 (optional subscription at
235 https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
236
237You can also contact the Authors:
238
239Marek Lindner <lindner_marek@yahoo.de>
240Simon Wunderlich <siwu@hrz.tu-chemnitz.de>