Documentation/networking/batman-adv.txt

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