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 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>