About Kernel Documentation Linux Kernel Contact Linux Resources Linux Blog

Documentation / networking / batman-adv.txt




Custom Search

Based on kernel version 4.9. Page generated on 2016-12-21 14:36 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	The batman-adv soft-interface can be created using  the  iproute2
47	tool "ip"
48	
49	# ip link add name bat0 type batadv
50	
51	To  activate a  given  interface  simply  attach it to the "bat0"
52	interface
53	
54	# ip link set dev eth0 master bat0
55	
56	Repeat  this step for all interfaces you wish to add.  Now batman
57	starts using/broadcasting on this/these interface(s).
58	
59	By reading the "iface_status" file you can check its status:
60	
61	# cat /sys/class/net/eth0/batman_adv/iface_status
62	# active
63	
64	To  deactivate  an  interface  you  have   to  detach it from the
65	"bat0" interface:
66	
67	# ip link set dev eth0 nomaster
68	
69	
70	All  mesh  wide  settings  can be found in batman's own interface
71	folder:
72	
73	# ls /sys/class/net/bat0/mesh/
74	#aggregated_ogms        distributed_arp_table  gw_sel_class    orig_interval
75	#ap_isolation           fragmentation          hop_penalty     routing_algo
76	#bonding                gw_bandwidth           isolation_mark  vlan0
77	#bridge_loop_avoidance  gw_mode                log_level
78	
79	There is a special folder for debugging information:
80	
81	# ls /sys/kernel/debug/batman_adv/bat0/
82	# bla_backbone_table  log                 transtable_global
83	# bla_claim_table     originators         transtable_local
84	# gateways            socket
85	
86	Some of the files contain all sort of status information  regard-
87	ing  the  mesh  network.  For  example, you can view the table of
88	originators (mesh participants) with:
89	
90	# cat /sys/kernel/debug/batman_adv/bat0/originators
91	
92	Other files allow to change batman's behaviour to better fit your
93	requirements.  For instance, you can check the current originator
94	interval (value in milliseconds which determines how often batman
95	sends its broadcast packets):
96	
97	# cat /sys/class/net/bat0/mesh/orig_interval
98	# 1000
99	
100	and also change its value:
101	
102	# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
103	
104	In very mobile scenarios, you might want to adjust the originator
105	interval to a lower value. This will make the mesh  more  respon-
106	sive to topology changes, but will also increase the overhead.
107	
108	
109	USAGE
110	-----
111	
112	To  make use of your newly created mesh, batman advanced provides
113	a new interface "bat0" which you should use from this  point  on.
114	All  interfaces  added  to  batman  advanced are not relevant any
115	longer because batman handles them for you. Basically, one "hands
116	over" the data by using the batman interface and batman will make
117	sure it reaches its destination.
118	
119	The "bat0" interface can be used like any  other  regular  inter-
120	face.  It needs an IP address which can be either statically con-
121	figured or dynamically (by using DHCP or similar services):
122	
123	# NodeA: ip link set up dev bat0
124	# NodeA: ip addr add 192.168.0.1/24 dev bat0
125	
126	# NodeB: ip link set up dev bat0
127	# NodeB: ip addr add 192.168.0.2/24 dev bat0
128	# NodeB: ping 192.168.0.1
129	
130	Note:  In  order to avoid problems remove all IP addresses previ-
131	ously assigned to interfaces now used by batman advanced, e.g.
132	
133	# ip addr flush dev eth0
134	
135	
136	LOGGING/DEBUGGING
137	-----------------
138	
139	All error messages, warnings and information messages are sent to
140	the kernel log. Depending on your operating  system  distribution
141	this  can  be read in one of a number of ways. Try using the com-
142	mands: dmesg, logread, or looking in the files  /var/log/kern.log
143	or  /var/log/syslog.  All  batman-adv  messages are prefixed with
144	"batman-adv:" So to see just these messages try
145	
146	# dmesg | grep batman-adv
147	
148	When investigating problems with your mesh network  it  is  some-
149	times  necessary  to see more detail debug messages. This must be
150	enabled when compiling the batman-adv module. When building  bat-
151	man-adv  as  part of kernel, use "make menuconfig" and enable the
152	option "B.A.T.M.A.N. debugging".
153	
154	Those additional  debug messages can be accessed  using a special
155	file in debugfs
156	
157	# cat /sys/kernel/debug/batman_adv/bat0/log
158	
159	The additional debug output is by default disabled. It can be en-
160	abled  during run time. Following log_levels are defined:
161	
162	0 - All  debug  output  disabled
163	1 - Enable messages related to routing / flooding / broadcasting
164	2 - Enable messages related to route added / changed / deleted
165	4 - Enable messages related to translation table operations
166	8 - Enable messages related to bridge loop avoidance
167	16 - Enable messaged related to DAT, ARP snooping and parsing
168	31 - Enable all messages
169	
170	The debug output can be changed at runtime  using  the  file
171	/sys/class/net/bat0/mesh/log_level. e.g.
172	
173	# echo 6 > /sys/class/net/bat0/mesh/log_level
174	
175	will enable debug messages for when routes change.
176	
177	Counters for different types of packets entering and leaving the
178	batman-adv module are available through ethtool:
179	
180	# ethtool --statistics bat0
181	
182	
183	BATCTL
184	------
185	
186	As batman advanced operates on layer 2 all hosts participating in
187	the  virtual switch are completely transparent for all  protocols
188	above layer 2. Therefore the common diagnosis tools do  not  work
189	as  expected.  To  overcome these problems batctl was created. At
190	the  moment the  batctl contains ping,  traceroute,  tcpdump  and
191	interfaces to the kernel module settings.
192	
193	For more information, please see the manpage (man batctl).
194	
195	batctl is available on https://www.open-mesh.org/
196	
197	
198	CONTACT
199	-------
200	
201	Please send us comments, experiences, questions, anything :)
202	
203	IRC:            #batman   on   irc.freenode.org
204	Mailing-list:   b.a.t.m.a.n@open-mesh.org (optional  subscription
205	          at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
206	
207	You can also contact the Authors:
208	
209	Marek  Lindner  <mareklindner@neomailbox.ch>
210	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.