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_claim_table    log                socket             transtable_local
  80# gateways           originators        transtable_global  vis_data
  81
  82Some of the files contain all sort of status information  regard-
  83ing  the  mesh  network.  For  example, you can view the table of
  84originators (mesh participants) with:
  85
  86# cat /sys/kernel/debug/batman_adv/bat0/originators
  87
  88Other files allow to change batman's behaviour to better fit your
  89requirements.  For instance, you can check the current originator
  90interval (value in milliseconds which determines how often batman
  91sends its broadcast packets):
  92
  93# cat /sys/class/net/bat0/mesh/orig_interval
  94# 1000
  95
  96and also change its value:
  97
  98# echo 3000 > /sys/class/net/bat0/mesh/orig_interval
  99
 100In very mobile scenarios, you might want to adjust the originator
 101interval to a lower value. This will make the mesh  more  respon-
 102sive to topology changes, but will also increase the overhead.
 103
 104
 105USAGE
 106-----
 107
 108To  make use of your newly created mesh, batman advanced provides
 109a new interface "bat0" which you should use from this  point  on.
 110All  interfaces  added  to  batman  advanced are not relevant any
 111longer because batman handles them for you. Basically, one "hands
 112over" the data by using the batman interface and batman will make
 113sure it reaches its destination.
 114
 115The "bat0" interface can be used like any  other  regular  inter-
 116face.  It needs an IP address which can be either statically con-
 117figured 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
 123Note:  In  order to avoid problems remove all IP addresses previ-
 124ously assigned to interfaces now used by batman advanced, e.g.
 125
 126# ifconfig eth0 0.0.0.0
 127
 128
 129VISUALIZATION
 130-------------
 131
 132If you want topology visualization, at least one mesh  node  must
 133be configured as VIS-server:
 134
 135# echo "server" > /sys/class/net/bat0/mesh/vis_mode
 136
 137Each  node  is  either configured as "server" or as "client" (de-
 138fault: "client").  Clients send their topology data to the server
 139next to them, and server synchronize with other servers. If there
 140is no server configured (default) within the  mesh,  no  topology
 141information   will  be  transmitted.  With  these  "synchronizing
 142servers", there can be 1 or more vis servers sharing the same (or
 143at least very similar) data.
 144
 145When  configured  as  server,  you can get a topology snapshot of
 146your mesh:
 147
 148# cat /sys/kernel/debug/batman_adv/bat0/vis_data
 149
 150This raw output is intended to be easily parsable and convertable
 151with  other tools. Have a look at the batctl README if you want a
 152vis output in dot or json format for instance and how those  out-
 153puts could then be visualised in an image.
 154
 155The raw format consists of comma separated values per entry where
 156each entry is giving information about a  certain  source  inter-
 157face.  Each  entry can/has to have the following values:
 158-> "mac" - mac address of an originator's source interface
 159           (each line begins with it)
 160-> "TQ mac  value"  -  src mac's link quality towards mac address
 161                       of a neighbor originator's interface which
 162                       is being used for routing
 163-> "TT mac" - TT announced by source mac
 164-> "PRIMARY" - this  is a primary interface
 165-> "SEC mac" - secondary mac address of source
 166               (requires preceding PRIMARY)
 167
 168The TQ value has a range from 4 to 255 with 255 being  the  best.
 169The TT entries are showing which hosts are connected to the mesh
 170via bat0 or being bridged into the mesh network.  The PRIMARY/SEC
 171values are only applied on primary interfaces
 172
 173
 174LOGGING/DEBUGGING
 175-----------------
 176
 177All error messages, warnings and information messages are sent to
 178the kernel log. Depending on your operating  system  distribution
 179this  can  be read in one of a number of ways. Try using the com-
 180mands: dmesg, logread, or looking in the files  /var/log/kern.log
 181or  /var/log/syslog.  All  batman-adv  messages are prefixed with
 182"batman-adv:" So to see just these messages try
 183
 184# dmesg | grep batman-adv
 185
 186When investigating problems with your mesh network  it  is  some-
 187times  necessary  to see more detail debug messages. This must be
 188enabled when compiling the batman-adv module. When building  bat-
 189man-adv  as  part of kernel, use "make menuconfig" and enable the
 190option "B.A.T.M.A.N. debugging".
 191
 192Those additional  debug messages can be accessed  using a special
 193file in debugfs
 194
 195# cat /sys/kernel/debug/batman_adv/bat0/log
 196
 197The additional debug output is by default disabled. It can be en-
 198abled  during run time. Following log_levels are defined:
 199
 2000 - All  debug  output  disabled
 2011 - Enable messages related to routing / flooding / broadcasting
 2022 - Enable messages related to route added / changed / deleted
 2034 - Enable messages related to translation table operations
 2048 - Enable messages related to bridge loop avoidance
 20515 - enable all messages
 206
 207The debug output can be changed at runtime  using  the  file
 208/sys/class/net/bat0/mesh/log_level. e.g.
 209
 210# echo 6 > /sys/class/net/bat0/mesh/log_level
 211
 212will enable debug messages for when routes change.
 213
 214Counters for different types of packets entering and leaving the
 215batman-adv module are available through ethtool:
 216
 217# ethtool --statistics bat0
 218
 219
 220BATCTL
 221------
 222
 223As batman advanced operates on layer 2 all hosts participating in
 224the  virtual switch are completely transparent for all  protocols
 225above layer 2. Therefore the common diagnosis tools do  not  work
 226as  expected.  To  overcome these problems batctl was created. At
 227the  moment the  batctl contains ping,  traceroute,  tcpdump  and
 228interfaces to the kernel module settings.
 229
 230For more information, please see the manpage (man batctl).
 231
 232batctl is available on http://www.open-mesh.org/
 233
 234
 235CONTACT
 236-------
 237
 238Please send us comments, experiences, questions, anything :)
 239
 240IRC:            #batman   on   irc.freenode.org
 241Mailing-list:   b.a.t.m.a.n@open-mesh.org (optional  subscription
 242          at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
 243
 244You can also contact the Authors:
 245
 246Marek  Lindner  <lindner_marek@yahoo.de>
 247Simon  Wunderlich  <siwu@hrz.tu-chemnitz.de>
 248
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