1========== 2batman-adv 3========== 4 5Batman advanced is a new approach to wireless networking which does no longer 6operate on the IP basis. Unlike the batman daemon, which exchanges information 7using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI 8Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It 9emulates a virtual network switch of all nodes participating. Therefore all 10nodes appear to be link local, thus all higher operating protocols won't be 11affected by any changes within the network. You can run almost any protocol 12above batman advanced, prominent examples are: IPv4, IPv6, DHCP, IPX. 13 14Batman advanced was implemented as a Linux kernel driver to reduce the overhead 15to a minimum. It does not depend on any (other) network driver, and can be used 16on wifi as well as ethernet lan, vpn, etc ... (anything with ethernet-style 17layer 2). 18 19 20Configuration 21============= 22 23Load the batman-adv module into your kernel:: 24 25 $ insmod batman-adv.ko 26 27The module is now waiting for activation. You must add some interfaces on which 28batman can operate. After loading the module batman advanced will scan your 29systems interfaces to search for compatible interfaces. Once found, it will 30create subfolders in the ``/sys`` directories of each supported interface, 31e.g.:: 32 33 $ ls /sys/class/net/eth0/batman_adv/ 34 elp_interval iface_status mesh_iface throughput_override 35 36If an interface does not have the ``batman_adv`` subfolder, it probably is not 37supported. Not supported interfaces are: loopback, non-ethernet and batman's 38own interfaces. 39 40Note: After the module was loaded it will continuously watch for new 41interfaces to verify the compatibility. There is no need to reload the module 42if you plug your USB wifi adapter into your machine after batman advanced was 43initially loaded. 44 45The batman-adv soft-interface can be created using the iproute2 tool ``ip``:: 46 47 $ ip link add name bat0 type batadv 48 49To activate a given interface simply attach it to the ``bat0`` interface:: 50 51 $ ip link set dev eth0 master bat0 52 53Repeat this step for all interfaces you wish to add. Now batman starts 54using/broadcasting on this/these interface(s). 55 56By reading the "iface_status" file you can check its status:: 57 58 $ cat /sys/class/net/eth0/batman_adv/iface_status 59 active 60 61To deactivate an interface you have to detach it from the "bat0" interface:: 62 63 $ ip link set dev eth0 nomaster 64 65 66All mesh wide settings can be found in batman's own interface folder:: 67 68 $ ls /sys/class/net/bat0/mesh/ 69 aggregated_ogms fragmentation isolation_mark routing_algo 70 ap_isolation gw_bandwidth log_level vlan0 71 bonding gw_mode multicast_mode 72 bridge_loop_avoidance gw_sel_class network_coding 73 distributed_arp_table hop_penalty orig_interval 74 75There is a special folder for debugging information:: 76 77 $ ls /sys/kernel/debug/batman_adv/bat0/ 78 bla_backbone_table log neighbors transtable_local 79 bla_claim_table mcast_flags originators 80 dat_cache nc socket 81 gateways nc_nodes transtable_global 82 83Some of the files contain all sort of status information regarding the mesh 84network. For example, you can view the table of originators (mesh 85participants) with:: 86 87 $ cat /sys/kernel/debug/batman_adv/bat0/originators 88 89Other files allow to change batman's behaviour to better fit your requirements. 90For instance, you can check the current originator interval (value in 91milliseconds which determines how often batman sends 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 interval to a 101lower value. This will make the mesh more responsive to topology changes, but 102will also increase the overhead. 103 104 105Usage 106===== 107 108To make use of your newly created mesh, batman advanced provides a new 109interface "bat0" which you should use from this point on. All interfaces added 110to batman advanced are not relevant any longer because batman handles them for 111you. Basically, one "hands over" the data by using the batman interface and 112batman will make sure it reaches its destination. 113 114The "bat0" interface can be used like any other regular interface. It needs an 115IP address which can be either statically configured or dynamically (by using 116DHCP 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 125Note: In order to avoid problems remove all IP addresses previously assigned to 126interfaces now used by batman advanced, e.g.:: 127 128 $ ip addr flush dev eth0 129 130 131Logging/Debugging 132================= 133 134All error messages, warnings and information messages are sent to the kernel 135log. Depending on your operating system distribution this can be read in one of 136a number of ways. Try using the commands: ``dmesg``, ``logread``, or looking in 137the files ``/var/log/kern.log`` or ``/var/log/syslog``. All batman-adv messages 138are prefixed with "batman-adv:" So to see just these messages try:: 139 140 $ dmesg | grep batman-adv 141 142When investigating problems with your mesh network, it is sometimes necessary to 143see more detail debug messages. This must be enabled when compiling the 144batman-adv module. When building batman-adv as part of kernel, use "make 145menuconfig" and enable the option ``B.A.T.M.A.N. debugging`` 146(``CONFIG_BATMAN_ADV_DEBUG=y``). 147 148Those additional debug messages can be accessed using a special file in 149debugfs:: 150 151 $ cat /sys/kernel/debug/batman_adv/bat0/log 152 153The additional debug output is by default disabled. It can be enabled during 154run time. Following log_levels are defined: 155 156.. flat-table:: 157 158 * - 0 159 - All debug output disabled 160 * - 1 161 - Enable messages related to routing / flooding / broadcasting 162 * - 2 163 - Enable messages related to route added / changed / deleted 164 * - 4 165 - Enable messages related to translation table operations 166 * - 8 167 - Enable messages related to bridge loop avoidance 168 * - 16 169 - Enable messages related to DAT, ARP snooping and parsing 170 * - 32 171 - Enable messages related to network coding 172 * - 64 173 - Enable messages related to multicast 174 * - 128 175 - Enable messages related to throughput meter 176 * - 255 177 - Enable all messages 178 179The debug output can be changed at runtime using the file 180``/sys/class/net/bat0/mesh/log_level``. e.g.:: 181 182 $ echo 6 > /sys/class/net/bat0/mesh/log_level 183 184will enable debug messages for when routes change. 185 186Counters for different types of packets entering and leaving the batman-adv 187module are available through ethtool:: 188 189 $ ethtool --statistics bat0 190 191 192batctl 193====== 194 195As batman advanced operates on layer 2, all hosts participating in the virtual 196switch are completely transparent for all protocols above layer 2. Therefore 197the common diagnosis tools do not work as expected. To overcome these problems, 198batctl was created. At the moment the batctl contains ping, traceroute, tcpdump 199and interfaces to the kernel module settings. 200 201For more information, please see the manpage (``man batctl``). 202 203batctl is available on https://www.open-mesh.org/ 204 205 206Contact 207======= 208 209Please send us comments, experiences, questions, anything :) 210 211IRC: 212 #batman on irc.freenode.org 213Mailing-list: 214 b.a.t.m.a.n@open-mesh.org (optional subscription at 215 https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n) 216 217You can also contact the Authors: 218 219* Marek Lindner <mareklindner@neomailbox.ch> 220* Simon Wunderlich <sw@simonwunderlich.de> 221