1.. SPDX-License-Identifier: GPL-2.0 2 3========== 4batman-adv 5========== 6 7Batman advanced is a new approach to wireless networking which does no longer 8operate on the IP basis. Unlike the batman daemon, which exchanges information 9using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI 10Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It 11emulates a virtual network switch of all nodes participating. Therefore all 12nodes appear to be link local, thus all higher operating protocols won't be 13affected by any changes within the network. You can run almost any protocol 14above batman advanced, prominent examples are: IPv4, IPv6, DHCP, IPX. 15 16Batman advanced was implemented as a Linux kernel driver to reduce the overhead 17to a minimum. It does not depend on any (other) network driver, and can be used 18on wifi as well as ethernet lan, vpn, etc ... (anything with ethernet-style 19layer 2). 20 21 22Configuration 23============= 24 25Load the batman-adv module into your kernel:: 26 27 $ insmod batman-adv.ko 28 29The module is now waiting for activation. You must add some interfaces on which 30batman can operate. After loading the module batman advanced will scan your 31systems interfaces to search for compatible interfaces. Once found, it will 32create subfolders in the ``/sys`` directories of each supported interface, 33e.g.:: 34 35 $ ls /sys/class/net/eth0/batman_adv/ 36 elp_interval iface_status mesh_iface throughput_override 37 38If an interface does not have the ``batman_adv`` subfolder, it probably is not 39supported. Not supported interfaces are: loopback, non-ethernet and batman's 40own interfaces. 41 42Note: After the module was loaded it will continuously watch for new 43interfaces to verify the compatibility. There is no need to reload the module 44if you plug your USB wifi adapter into your machine after batman advanced was 45initially loaded. 46 47The batman-adv soft-interface can be created using the iproute2 tool ``ip``:: 48 49 $ ip link add name bat0 type batadv 50 51To activate a given interface simply attach it to the ``bat0`` interface:: 52 53 $ ip link set dev eth0 master bat0 54 55Repeat this step for all interfaces you wish to add. Now batman starts 56using/broadcasting on this/these interface(s). 57 58By reading the "iface_status" file you can check its status:: 59 60 $ cat /sys/class/net/eth0/batman_adv/iface_status 61 active 62 63To deactivate an interface you have to detach it from the "bat0" interface:: 64 65 $ ip link set dev eth0 nomaster 66 67 68All mesh wide settings can be found in batman's own interface folder:: 69 70 $ ls /sys/class/net/bat0/mesh/ 71 aggregated_ogms fragmentation isolation_mark routing_algo 72 ap_isolation gw_bandwidth log_level vlan0 73 bonding gw_mode multicast_mode 74 bridge_loop_avoidance gw_sel_class network_coding 75 distributed_arp_table hop_penalty orig_interval 76 77There is a special folder for debugging information:: 78 79 $ ls /sys/kernel/debug/batman_adv/bat0/ 80 bla_backbone_table log neighbors transtable_local 81 bla_claim_table mcast_flags originators 82 dat_cache nc socket 83 gateways nc_nodes transtable_global 84 85Some of the files contain all sort of status information regarding the mesh 86network. For example, you can view the table of originators (mesh 87participants) with:: 88 89 $ cat /sys/kernel/debug/batman_adv/bat0/originators 90 91Other files allow to change batman's behaviour to better fit your requirements. 92For instance, you can check the current originator interval (value in 93milliseconds which determines how often batman sends its broadcast packets):: 94 95 $ cat /sys/class/net/bat0/mesh/orig_interval 96 1000 97 98and also change its value:: 99 100 $ echo 3000 > /sys/class/net/bat0/mesh/orig_interval 101 102In very mobile scenarios, you might want to adjust the originator interval to a 103lower value. This will make the mesh more responsive to topology changes, but 104will also increase the overhead. 105 106 107Usage 108===== 109 110To make use of your newly created mesh, batman advanced provides a new 111interface "bat0" which you should use from this point on. All interfaces added 112to batman advanced are not relevant any longer because batman handles them for 113you. Basically, one "hands over" the data by using the batman interface and 114batman will make sure it reaches its destination. 115 116The "bat0" interface can be used like any other regular interface. It needs an 117IP address which can be either statically configured or dynamically (by using 118DHCP or similar services):: 119 120 NodeA: ip link set up dev bat0 121 NodeA: ip addr add 192.168.0.1/24 dev bat0 122 123 NodeB: ip link set up dev bat0 124 NodeB: ip addr add 192.168.0.2/24 dev bat0 125 NodeB: ping 192.168.0.1 126 127Note: In order to avoid problems remove all IP addresses previously assigned to 128interfaces now used by batman advanced, e.g.:: 129 130 $ ip addr flush dev eth0 131 132 133Logging/Debugging 134================= 135 136All error messages, warnings and information messages are sent to the kernel 137log. Depending on your operating system distribution this can be read in one of 138a number of ways. Try using the commands: ``dmesg``, ``logread``, or looking in 139the files ``/var/log/kern.log`` or ``/var/log/syslog``. All batman-adv messages 140are prefixed with "batman-adv:" So to see just these messages try:: 141 142 $ dmesg | grep batman-adv 143 144When investigating problems with your mesh network, it is sometimes necessary to 145see more detail debug messages. This must be enabled when compiling the 146batman-adv module. When building batman-adv as part of kernel, use "make 147menuconfig" and enable the option ``B.A.T.M.A.N. debugging`` 148(``CONFIG_BATMAN_ADV_DEBUG=y``). 149 150Those additional debug messages can be accessed using a special file in 151debugfs:: 152 153 $ cat /sys/kernel/debug/batman_adv/bat0/log 154 155The additional debug output is by default disabled. It can be enabled during 156run time. Following log_levels are defined: 157 158.. flat-table:: 159 160 * - 0 161 - All debug output disabled 162 * - 1 163 - Enable messages related to routing / flooding / broadcasting 164 * - 2 165 - Enable messages related to route added / changed / deleted 166 * - 4 167 - Enable messages related to translation table operations 168 * - 8 169 - Enable messages related to bridge loop avoidance 170 * - 16 171 - Enable messages related to DAT, ARP snooping and parsing 172 * - 32 173 - Enable messages related to network coding 174 * - 64 175 - Enable messages related to multicast 176 * - 128 177 - Enable messages related to throughput meter 178 * - 255 179 - Enable all messages 180 181The debug output can be changed at runtime using the file 182``/sys/class/net/bat0/mesh/log_level``. e.g.:: 183 184 $ echo 6 > /sys/class/net/bat0/mesh/log_level 185 186will enable debug messages for when routes change. 187 188Counters for different types of packets entering and leaving the batman-adv 189module are available through ethtool:: 190 191 $ ethtool --statistics bat0 192 193 194batctl 195====== 196 197As batman advanced operates on layer 2, all hosts participating in the virtual 198switch are completely transparent for all protocols above layer 2. Therefore 199the common diagnosis tools do not work as expected. To overcome these problems, 200batctl was created. At the moment the batctl contains ping, traceroute, tcpdump 201and interfaces to the kernel module settings. 202 203For more information, please see the manpage (``man batctl``). 204 205batctl is available on https://www.open-mesh.org/ 206 207 208Contact 209======= 210 211Please send us comments, experiences, questions, anything :) 212 213IRC: 214 #batman on irc.freenode.org 215Mailing-list: 216 b.a.t.m.a.n@open-mesh.org (optional subscription at 217 https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n) 218 219You can also contact the Authors: 220 221* Marek Lindner <mareklindner@neomailbox.ch> 222* Simon Wunderlich <sw@simonwunderlich.de> 223