linux/Documentation/networking/batman-adv.txt
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   1BATMAN-ADV
   2----------
   3
   4Batman  advanced  is  a new approach to wireless networking which
   5does no longer operate on the IP basis. Unlike the batman daemon,
   6which  exchanges  information  using UDP packets and sets routing
   7tables, batman-advanced operates on ISO/OSI Layer 2 only and uses
   8and  routes  (or  better: bridges) Ethernet Frames. It emulates a
   9virtual network switch of all nodes participating.  Therefore all
  10nodes  appear  to be link local, thus all higher operating proto-
  11cols won't be affected by any changes within the network. You can
  12run almost any protocol above batman advanced, prominent examples
  13are: IPv4, IPv6, DHCP, IPX.
  14
  15Batman advanced was implemented as a Linux kernel driver  to  re-
  16duce the overhead to a minimum. It does not depend on any (other)
  17network driver, and can be used on wifi as well as ethernet  lan,
  18vpn,  etc ... (anything with ethernet-style layer 2).
  19
  20
  21CONFIGURATION
  22-------------
  23
  24Load the batman-adv module into your kernel:
  25
  26# insmod batman-adv.ko
  27
  28The  module  is now waiting for activation. You must add some in-
  29terfaces on which batman can operate. After  loading  the  module
  30batman  advanced  will scan your systems interfaces to search for
  31compatible interfaces. Once found, it will create  subfolders  in
  32the /sys directories of each supported interface, e.g.
  33
  34# ls /sys/class/net/eth0/batman_adv/
  35# iface_status  mesh_iface
  36
  37If an interface does not have the "batman_adv" subfolder it prob-
  38ably is not supported. Not supported  interfaces  are:  loopback,
  39non-ethernet and batman's own interfaces.
  40
  41Note:  After the module was loaded it will continuously watch for
  42new interfaces to verify the compatibility. There is no  need  to
  43reload the module if you plug your USB wifi adapter into your ma-
  44chine after batman advanced was initially loaded.
  45
  46To 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
  51Repeat  this step for all interfaces you wish to add.  Now batman
  52starts using/broadcasting on this/these interface(s).
  53
  54By reading the "iface_status" file you can check its status:
  55
  56# cat /sys/class/net/eth0/batman_adv/iface_status
  57# active
  58
  59To 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
  65All  mesh  wide  settings  can be found in batman's own interface
  66folder:
  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            vis_mode
  73# fragmentation
  74
  75
  76There is a special folder for debugging information:
  77
  78# ls /sys/kernel/debug/batman_adv/bat0/
  79# bla_backbone_table  log                 transtable_global
  80# bla_claim_table     originators         transtable_local
  81# gateways            socket              vis_data
  82
  83Some of the files contain all sort of status information  regard-
  84ing  the  mesh  network.  For  example, you can view the table of
  85originators (mesh participants) with:
  86
  87# cat /sys/kernel/debug/batman_adv/bat0/originators
  88
  89Other files allow to change batman's behaviour to better fit your
  90requirements.  For instance, you can check the current originator
  91interval (value in milliseconds which determines how often batman
  92sends its broadcast packets):
  93
  94# cat /sys/class/net/bat0/mesh/orig_interval
  95# 1000
  96
  97and also change its value:
  98
  99# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
 100
 101In very mobile scenarios, you might want to adjust the originator
 102interval to a lower value. This will make the mesh  more  respon-
 103sive to topology changes, but will also increase the overhead.
 104
 105
 106USAGE
 107-----
 108
 109To  make use of your newly created mesh, batman advanced provides
 110a new interface "bat0" which you should use from this  point  on.
 111All  interfaces  added  to  batman  advanced are not relevant any
 112longer because batman handles them for you. Basically, one "hands
 113over" the data by using the batman interface and batman will make
 114sure it reaches its destination.
 115
 116The "bat0" interface can be used like any  other  regular  inter-
 117face.  It needs an IP address which can be either statically con-
 118figured or dynamically (by using DHCP or similar services):
 119
 120# NodeA: ifconfig bat0 192.168.0.1
 121# NodeB: ifconfig bat0 192.168.0.2
 122# NodeB: ping 192.168.0.1
 123
 124Note:  In  order to avoid problems remove all IP addresses previ-
 125ously assigned to interfaces now used by batman advanced, e.g.
 126
 127# ifconfig eth0 0.0.0.0
 128
 129
 130VISUALIZATION
 131-------------
 132
 133If you want topology visualization, at least one mesh  node  must
 134be configured as VIS-server:
 135
 136# echo "server" > /sys/class/net/bat0/mesh/vis_mode
 137
 138Each  node  is  either configured as "server" or as "client" (de-
 139fault: "client").  Clients send their topology data to the server
 140next to them, and server synchronize with other servers. If there
 141is no server configured (default) within the  mesh,  no  topology
 142information   will  be  transmitted.  With  these  "synchronizing
 143servers", there can be 1 or more vis servers sharing the same (or
 144at least very similar) data.
 145
 146When  configured  as  server,  you can get a topology snapshot of
 147your mesh:
 148
 149# cat /sys/kernel/debug/batman_adv/bat0/vis_data
 150
 151This raw output is intended to be easily parsable and convertable
 152with  other tools. Have a look at the batctl README if you want a
 153vis output in dot or json format for instance and how those  out-
 154puts could then be visualised in an image.
 155
 156The raw format consists of comma separated values per entry where
 157each entry is giving information about a  certain  source  inter-
 158face.  Each  entry can/has to have the following values:
 159-> "mac" - mac address of an originator's source interface
 160           (each line begins with it)
 161-> "TQ mac  value"  -  src mac's link quality towards mac address
 162                       of a neighbor originator's interface which
 163                       is being used for routing
 164-> "TT mac" - TT announced by source mac
 165-> "PRIMARY" - this  is a primary interface
 166-> "SEC mac" - secondary mac address of source
 167               (requires preceding PRIMARY)
 168
 169The TQ value has a range from 4 to 255 with 255 being  the  best.
 170The TT entries are showing which hosts are connected to the mesh
 171via bat0 or being bridged into the mesh network.  The PRIMARY/SEC
 172values are only applied on primary interfaces
 173
 174
 175LOGGING/DEBUGGING
 176-----------------
 177
 178All error messages, warnings and information messages are sent to
 179the kernel log. Depending on your operating  system  distribution
 180this  can  be read in one of a number of ways. Try using the com-
 181mands: dmesg, logread, or looking in the files  /var/log/kern.log
 182or  /var/log/syslog.  All  batman-adv  messages are prefixed with
 183"batman-adv:" So to see just these messages try
 184
 185# dmesg | grep batman-adv
 186
 187When investigating problems with your mesh network  it  is  some-
 188times  necessary  to see more detail debug messages. This must be
 189enabled when compiling the batman-adv module. When building  bat-
 190man-adv  as  part of kernel, use "make menuconfig" and enable the
 191option "B.A.T.M.A.N. debugging".
 192
 193Those additional  debug messages can be accessed  using a special
 194file in debugfs
 195
 196# cat /sys/kernel/debug/batman_adv/bat0/log
 197
 198The additional debug output is by default disabled. It can be en-
 199abled  during run time. Following log_levels are defined:
 200
 2010 - All  debug  output  disabled
 2021 - Enable messages related to routing / flooding / broadcasting
 2032 - Enable messages related to route added / changed / deleted
 2044 - Enable messages related to translation table operations
 2058 - Enable messages related to bridge loop avoidance
 20615 - enable all messages
 207
 208The debug output can be changed at runtime  using  the  file
 209/sys/class/net/bat0/mesh/log_level. e.g.
 210
 211# echo 6 > /sys/class/net/bat0/mesh/log_level
 212
 213will enable debug messages for when routes change.
 214
 215Counters for different types of packets entering and leaving the
 216batman-adv module are available through ethtool:
 217
 218# ethtool --statistics bat0
 219
 220
 221BATCTL
 222------
 223
 224As batman advanced operates on layer 2 all hosts participating in
 225the  virtual switch are completely transparent for all  protocols
 226above layer 2. Therefore the common diagnosis tools do  not  work
 227as  expected.  To  overcome these problems batctl was created. At
 228the  moment the  batctl contains ping,  traceroute,  tcpdump  and
 229interfaces to the kernel module settings.
 230
 231For more information, please see the manpage (man batctl).
 232
 233batctl is available on http://www.open-mesh.org/
 234
 235
 236CONTACT
 237-------
 238
 239Please send us comments, experiences, questions, anything :)
 240
 241IRC:            #batman   on   irc.freenode.org
 242Mailing-list:   b.a.t.m.a.n@open-mesh.org (optional  subscription
 243          at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
 244
 245You can also contact the Authors:
 246
 247Marek  Lindner  <lindner_marek@yahoo.de>
 248Simon  Wunderlich  <siwu@hrz.tu-chemnitz.de>
 249
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