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 # elp_interval  iface_status  mesh_iface  throughput_override
  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        fragmentation  isolation_mark  routing_algo
  75 # ap_isolation           gw_bandwidth   log_level       vlan0
  76 # bonding                gw_mode        multicast_mode
  77 # bridge_loop_avoidance  gw_sel_class   network_coding
  78 # distributed_arp_table  hop_penalty    orig_interval
  79
  80 There is a special folder for debugging information:
  81
  82 # ls /sys/kernel/debug/batman_adv/bat0/
  83 # bla_backbone_table  log          neighbors          transtable_local
  84 # bla_claim_table     mcast_flags  originators
  85 # dat_cache           nc           socket
  86 # gateways            nc_nodes     transtable_global
  87
  88 Some of the files contain all sort of status information  regard-
  89 ing  the  mesh  network.  For  example, you can view the table of
  90 originators (mesh participants) with:
  91
  92 # cat /sys/kernel/debug/batman_adv/bat0/originators
  93
  94 Other files allow to change batman's behaviour to better fit your
  95 requirements.  For instance, you can check the current originator
  96 interval (value in milliseconds which determines how often batman
  97 sends its broadcast packets):
  98
  99 # cat /sys/class/net/bat0/mesh/orig_interval
 100 # 1000
 101
 102 and also change its value:
 103
 104 # echo 3000 > /sys/class/net/bat0/mesh/orig_interval
 105
 106 In very mobile scenarios, you might want to adjust the originator
 107 interval to a lower value. This will make the mesh  more  respon-
 108 sive to topology changes, but will also increase the overhead.
 109
 110
 111 USAGE
 112 -----
 113
 114 To  make use of your newly created mesh, batman advanced provides
 115 a new interface "bat0" which you should use from this  point  on.
 116 All  interfaces  added  to  batman  advanced are not relevant any
 117 longer because batman handles them for you. Basically, one "hands
 118 over" the data by using the batman interface and batman will make
 119 sure it reaches its destination.
 120
 121 The "bat0" interface can be used like any  other  regular  inter-
 122 face.  It needs an IP address which can be either statically con-
 123 figured or dynamically (by using DHCP or similar services):
 124
 125 # NodeA: ip link set up dev bat0
 126 # NodeA: ip addr add 192.168.0.1/24 dev bat0
 127
 128 # NodeB: ip link set up dev bat0
 129 # NodeB: ip addr add 192.168.0.2/24 dev bat0
 130 # NodeB: ping 192.168.0.1
 131
 132 Note:  In  order to avoid problems remove all IP addresses previ-
 133 ously assigned to interfaces now used by batman advanced, e.g.
 134
 135 # ip addr flush dev eth0
 136
 137
 138 LOGGING/DEBUGGING
 139 -----------------
 140
 141 All error messages, warnings and information messages are sent to
 142 the kernel log. Depending on your operating  system  distribution
 143 this  can  be read in one of a number of ways. Try using the com-
 144 mands: dmesg, logread, or looking in the files  /var/log/kern.log
 145 or  /var/log/syslog.  All  batman-adv  messages are prefixed with
 146 "batman-adv:" So to see just these messages try
 147
 148 # dmesg | grep batman-adv
 149
 150 When investigating problems with your mesh network  it  is  some-
 151 times  necessary  to see more detail debug messages. This must be
 152 enabled when compiling the batman-adv module. When building  bat-
 153 man-adv  as  part of kernel, use "make menuconfig" and enable the
 154 option "B.A.T.M.A.N. debugging".
 155
 156 Those additional  debug messages can be accessed  using a special
 157 file in debugfs
 158
 159 # cat /sys/kernel/debug/batman_adv/bat0/log
 160
 161 The additional debug output is by default disabled. It can be en-
 162 abled  during run time. Following log_levels are defined:
 163
 164   0 - All  debug  output  disabled
 165   1 - Enable messages related to routing / flooding / broadcasting
 166   2 - Enable messages related to route added / changed / deleted
 167   4 - Enable messages related to translation table operations
 168   8 - Enable messages related to bridge loop avoidance
 169  16 - Enable messages related to DAT, ARP snooping and parsing
 170  32 - Enable messages related to network coding
 171  64 - Enable messages related to multicast
 172 128 - Enable messages related to throughput meter
 173 255 - Enable all messages
 174
 175 The debug output can be changed at runtime  using  the  file
 176 /sys/class/net/bat0/mesh/log_level. e.g.
 177
 178 # echo 6 > /sys/class/net/bat0/mesh/log_level
 179
 180 will enable debug messages for when routes change.
 181
 182 Counters for different types of packets entering and leaving the
 183 batman-adv module are available through ethtool:
 184
 185 # ethtool --statistics bat0
 186
 187
 188 BATCTL
 189 ------
 190
 191 As batman advanced operates on layer 2 all hosts participating in
 192 the  virtual switch are completely transparent for all  protocols
 193 above layer 2. Therefore the common diagnosis tools do  not  work
 194 as  expected.  To  overcome these problems batctl was created. At
 195 the  moment the  batctl contains ping,  traceroute,  tcpdump  and
 196 interfaces to the kernel module settings.
 197
 198 For more information, please see the manpage (man batctl).
 199
 200 batctl is available on https://www.open-mesh.org/
 201
 202
 203 CONTACT
 204 -------
 205
 206 Please send us comments, experiences, questions, anything :)
 207
 208 IRC:            #batman   on   irc.freenode.org
 209 Mailing-list:   b.a.t.m.a.n@open-mesh.org (optional  subscription
 210           at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)
 211
 212 You can also contact the Authors:
 213
 214 Marek  Lindner  <mareklindner@neomailbox.ch>
 215 Simon  Wunderlich  <sw@simonwunderlich.de>