About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / networking / batman-adv.txt




Custom Search

Based on kernel version 3.13. Page generated on 2014-01-20 22:03 EST.

1	BATMAN-ADV
2	----------
3	
4	Batman  advanced  is  a new approach to wireless networking which
5	does no longer operate on the IP basis. Unlike the batman daemon,
6	which  exchanges  information  using UDP packets and sets routing
7	tables, batman-advanced operates on ISO/OSI Layer 2 only and uses
8	and  routes  (or  better: bridges) Ethernet Frames. It emulates a
9	virtual network switch of all nodes participating.  Therefore all
10	nodes  appear  to be link local, thus all higher operating proto-
11	cols won't be affected by any changes within the network. You can
12	run almost any protocol above batman advanced, prominent examples
13	are: IPv4, IPv6, DHCP, IPX.
14	
15	Batman advanced was implemented as a Linux kernel driver  to  re-
16	duce the overhead to a minimum. It does not depend on any (other)
17	network driver, and can be used on wifi as well as ethernet  lan,
18	vpn,  etc ... (anything with ethernet-style layer 2).
19	
20	
21	CONFIGURATION
22	-------------
23	
24	Load the batman-adv module into your kernel:
25	
26	# insmod batman-adv.ko
27	
28	The  module  is now waiting for activation. You must add some in-
29	terfaces on which batman can operate. After  loading  the  module
30	batman  advanced  will scan your systems interfaces to search for
31	compatible interfaces. Once found, it will create  subfolders  in
32	the /sys directories of each supported interface, e.g.
33	
34	# ls /sys/class/net/eth0/batman_adv/
35	# iface_status  mesh_iface
36	
37	If an interface does not have the "batman_adv" subfolder it prob-
38	ably is not supported. Not supported  interfaces  are:  loopback,
39	non-ethernet and batman's own interfaces.
40	
41	Note:  After the module was loaded it will continuously watch for
42	new interfaces to verify the compatibility. There is no  need  to
43	reload the module if you plug your USB wifi adapter into your ma-
44	chine after batman advanced was initially loaded.
45	
46	To activate a  given  interface  simply  write  "bat0"  into  its
47	"mesh_iface" file inside the batman_adv subfolder:
48	
49	# echo bat0 > /sys/class/net/eth0/batman_adv/mesh_iface
50	
51	Repeat  this step for all interfaces you wish to add.  Now batman
52	starts using/broadcasting on this/these interface(s).
53	
54	By reading the "iface_status" file you can check its status:
55	
56	# cat /sys/class/net/eth0/batman_adv/iface_status
57	# active
58	
59	To deactivate an interface you have  to  write  "none"  into  its
60	"mesh_iface" file:
61	
62	# echo none > /sys/class/net/eth0/batman_adv/mesh_iface
63	
64	
65	All  mesh  wide  settings  can be found in batman's own interface
66	folder:
67	
68	# ls /sys/class/net/bat0/mesh/
69	# aggregated_ogms        gw_bandwidth           log_level
70	# ap_isolation           gw_mode                orig_interval
71	# bonding                gw_sel_class           routing_algo
72	# bridge_loop_avoidance  hop_penalty            fragmentation
73	
74	
75	There is a special folder for debugging information:
76	
77	# ls /sys/kernel/debug/batman_adv/bat0/
78	# bla_backbone_table  log                 transtable_global
79	# bla_claim_table     originators         transtable_local
80	# gateways            socket
81	
82	Some of the files contain all sort of status information  regard-
83	ing  the  mesh  network.  For  example, you can view the table of
84	originators (mesh participants) with:
85	
86	# cat /sys/kernel/debug/batman_adv/bat0/originators
87	
88	Other files allow to change batman's behaviour to better fit your
89	requirements.  For instance, you can check the current originator
90	interval (value in milliseconds which determines how often batman
91	sends its broadcast packets):
92	
93	# cat /sys/class/net/bat0/mesh/orig_interval
94	# 1000
95	
96	and also change its value:
97	
98	# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
99	
100	In very mobile scenarios, you might want to adjust the originator
101	interval to a lower value. This will make the mesh  more  respon-
102	sive to topology changes, but will also increase the overhead.
103	
104	
105	USAGE
106	-----
107	
108	To  make use of your newly created mesh, batman advanced provides
109	a new interface "bat0" which you should use from this  point  on.
110	All  interfaces  added  to  batman  advanced are not relevant any
111	longer because batman handles them for you. Basically, one "hands
112	over" the data by using the batman interface and batman will make
113	sure it reaches its destination.
114	
115	The "bat0" interface can be used like any  other  regular  inter-
116	face.  It needs an IP address which can be either statically con-
117	figured or dynamically (by using DHCP or similar services):
118	
119	# NodeA: ifconfig bat0 192.168.0.1
120	# NodeB: ifconfig bat0 192.168.0.2
121	# NodeB: ping 192.168.0.1
122	
123	Note:  In  order to avoid problems remove all IP addresses previ-
124	ously assigned to interfaces now used by batman advanced, e.g.
125	
126	# ifconfig eth0 0.0.0.0
127	
128	
129	LOGGING/DEBUGGING
130	-----------------
131	
132	All error messages, warnings and information messages are sent to
133	the kernel log. Depending on your operating  system  distribution
134	this  can  be read in one of a number of ways. Try using the com-
135	mands: dmesg, logread, or looking in the files  /var/log/kern.log
136	or  /var/log/syslog.  All  batman-adv  messages are prefixed with
137	"batman-adv:" So to see just these messages try
138	
139	# dmesg | grep batman-adv
140	
141	When investigating problems with your mesh network  it  is  some-
142	times  necessary  to see more detail debug messages. This must be
143	enabled when compiling the batman-adv module. When building  bat-
144	man-adv  as  part of kernel, use "make menuconfig" and enable the
145	option "B.A.T.M.A.N. debugging".
146	
147	Those additional  debug messages can be accessed  using a special
148	file in debugfs
149	
150	# cat /sys/kernel/debug/batman_adv/bat0/log
151	
152	The additional debug output is by default disabled. It can be en-
153	abled  during run time. Following log_levels are defined:
154	
155	0 - All  debug  output  disabled
156	1 - Enable messages related to routing / flooding / broadcasting
157	2 - Enable messages related to route added / changed / deleted
158	4 - Enable messages related to translation table operations
159	8 - Enable messages related to bridge loop avoidance
160	16 - Enable messaged related to DAT, ARP snooping and parsing
161	31 - Enable all messages
162	
163	The debug output can be changed at runtime  using  the  file
164	/sys/class/net/bat0/mesh/log_level. e.g.
165	
166	# echo 6 > /sys/class/net/bat0/mesh/log_level
167	
168	will enable debug messages for when routes change.
169	
170	Counters for different types of packets entering and leaving the
171	batman-adv module are available through ethtool:
172	
173	# ethtool --statistics bat0
174	
175	
176	BATCTL
177	------
178	
179	As batman advanced operates on layer 2 all hosts participating in
180	the  virtual switch are completely transparent for all  protocols
181	above layer 2. Therefore the common diagnosis tools do  not  work
182	as  expected.  To  overcome these problems batctl was created. At
183	the  moment the  batctl contains ping,  traceroute,  tcpdump  and
184	interfaces to the kernel module settings.
185	
186	For more information, please see the manpage (man batctl).
187	
188	batctl is available on http://www.open-mesh.org/
189	
190	
191	CONTACT
192	-------
193	
194	Please send us comments, experiences, questions, anything :)
195	
196	IRC:            #batman   on   irc.freenode.org
197	Mailing-list:   b.a.t.m.a.n@open-mesh.org (optional  subscription
198	          at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
199	
200	You can also contact the Authors:
201	
202	Marek  Lindner  <mareklindner@neomailbox.ch>
203	Simon  Wunderlich  <sw@simonwunderlich.de>
Hide Line Numbers
About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Information is copyright its respective author. All material is available from the Linux Kernel Source distributed under a GPL License. This page is provided as a free service by mjmwired.net.