Staging: batman-adv: updating README

[state: 22-03-2010]

[state: 03-05-2010]

BATMAN-ADV

----------

Batman-advanced is a new approach to wireless networking which does no longer

operate on the IP basis. Unlike B.A.T.M.A.N, which exchanges information

using UDP packets and sets routing tables, batman-advanced operates on ISO/OSI

Layer 2 only and uses and routes (or better: bridges) Ethernet Frames. It

emulates a virtual network switch of all nodes participating. Therefore all

nodes appear to be link local, thus all higher operating protocols won't be

affected by any changes within the network. You can run almost any protocol

above B.A.T.M.A.N. Advanced, prominent examples are: IPv4, IPv6, DHCP, IPX.

This is batman-advanced implemented as Linux kernel driver. It does not depend

on any network (other) driver, and can be used on wifi as well as ethernet,

Batman  advanced  is  a new approach to wireless networking which

does no longer operate on the IP basis. Unlike the batman daemon,

which  exchanges  information  using UDP packets and sets routing

tables, batman-advanced operates on ISO/OSI Layer 2 only and uses

and  routes  (or  better: bridges) Ethernet Frames. It emulates a

virtual network switch of all nodes participating.  Therefore all

nodes  appear  to be link local, thus all higher operating proto-

cols won't be affected by any changes within the network. You can

run almost any protocol above batman advanced, prominent examples

are: IPv4, IPv6, DHCP, IPX.

Batman advanced was implemented as a Linux kernel driver  to  re-

duce the overhead to a minimum. It does not depend on any (other)

network driver, and can be used on wifi as well as ethernet  lan,

vpn,  etc ... (anything with ethernet-style layer 2).

USAGE

-----

CONFIGURATION

-------------

insmod the batman-adv.ko in your kernel:

Load the batman-adv module into your kernel:

# insmod batman-adv.ko

the module is now waiting for activation. You must add some interfaces

on which batman can operate. Each interface must be added separately:

The  module  is now waiting for activation. You must add some in-

terfaces on which batman can operate. After  loading  the  module

batman  advanced  will scan your systems interfaces to search for

compatible interfaces. Once found, it will create  subfolders  in

the /sys directories of each supported interface, e.g.

# echo wlan0 > /proc/net/batman-adv/interfaces

# ls /sys/class/net/eth0/batman_adv/

# iface_status  mesh_iface

( # echo wlan1 > /proc/net/batman-adv/interfaces )

( # echo eth0 > /proc/net/batman-adv/interfaces )

( ... )

If an interface does not have the "batman_adv" subfolder it prob-

ably is not supported. Not supported  interfaces  are:  loopback,

non-ethernet and batman's own interfaces.

Now batman starts broadcasting on this interface.

You can now view the table of originators (mesh participants) with:

Note:  After the module was loaded it will continuously watch for

new interfaces to verify the compatibility. There is no  need  to

reload the module if you plug your USB wifi adapter into your ma-

chine after batman advanced was initially loaded.

# cat /proc/net/batman-adv/originators

To activate a  given  interface  simply  write  "bat0"  into  its

"mesh_iface" file inside the batman_adv subfolder:

The module will create a new interface "bat0", which can be used as a

regular interface:

# echo bat0 > /sys/class/net/eth0/batman_adv/mesh_iface

# ifconfig bat0 inet 192.168.0.1 up

# ping 192.168.0.2

...

Repeat  this step for all interfaces you wish to add.  Now batman

starts using/broadcasting on this/these interface(s).

---

If you want topology visualization, your meshnode must be configured

as VIS-server:

By reading the "iface_status" file you can check its status:

# echo "server" > /proc/net/batman-adv/vis_server

# cat /sys/class/net/eth0/batman_adv/iface_status

# active

Each node is either configured as "server" or as "client" (default:

"client"). Clients send their topology data to the server next to them,

and server synchronize with other servers. If there is no server

configured (default) within the mesh, no topology information will be

transmitted. With these "synchronizing servers", there can be 1 or

more vis servers sharing the same (or at least very similar) data.

To deactivate an interface you have  to  write  "none"  into  its

"mesh_iface" file:

When configured as server, you can get a topology snapshot of your mesh:

# echo none > /sys/class/net/eth0/batman_adv/mesh_iface

# cat /proc/net/batman-adv/vis_data

This raw output is intended to be easily parsable and convertable with

other tools. Have a look at the batctl README if you want a vis output

in dot or json format for instance and how those outputs could then be

visualised in an image.

All  mesh  wide  settings  can be found in batman's own interface

folder:

The raw format consists of comma seperated values per entry where each

entry is giving information about a certain source interface. Each entry

can/has to have the following values:

-> "mac" -> mac address of an originator's source interface

           (each line begins with it)

-> "TQ mac value" -> src mac's link quality towards mac address of a neighbor

                     originator's interface which is being used for routing

-> "HNA mac" -> HNA announced by source mac

-> "PRIMARY" -> this is a primary interface

-> "SEC mac" -> secondary mac address of source (requires preceeding

-> PRIMARY)

#  ls  /sys/class/net/bat0/mesh/

#  aggregate_ogm   originators        transtable_global  vis_mode

#  orig_interval   transtable_local   vis_data

The TQ value has a range from 4 to 255 with 255 being the best.

The HNA entries are showing which hosts are connected to the mesh via bat0

or being bridged into the mesh network.

The PRIMARY/SEC values are only applied on primary interfaces

---

Some of the files contain all sort of status information  regard-

ing  the  mesh  network.  For  example, you can view the table of

originators (mesh participants) with:

# cat /sys/class/net/bat0/mesh/originators

Other files allow to change batman's behaviour to better fit your

requirements.  For instance, you can check the current originator

interval (value in milliseconds which determines how often batman

sends its broadcast packets):

# cat /sys/class/net/bat0/mesh/orig_interval

# status: 1000

and also change its value:

# echo 3000 > /sys/class/net/bat0/mesh/orig_interval

In very mobile scenarios, you might want to adjust the originator

interval to a lower value. This will make the mesh more responsive to

topology changes, but will also increase the overhead. Please make sure

that all nodes in your mesh use the same interval. The default value

is 1000 ms (1 second).

interval to a lower value. This will make the mesh  more  respon-

sive to topology changes, but will also increase the overhead.

USAGE

-----

To  make use of your newly created mesh, batman advanced provides

a new interface "bat0" which you should use from this  point  on.

All  interfaces  added  to  batman  advanced are not relevant any

longer because batman handles them for you. Basically, one "hands

over" the data by using the batman interface and batman will make

sure it reaches its destination.

The "bat0" interface can be used like any  other  regular  inter-

face.  It needs an IP address which can be either statically con-

figured or dynamically (by using DHCP or similar services):

# echo 1000 > /proc/net/batman-adv/orig_interval

# NodeA: ifconfig bat0 192.168.0.1

# NodeB: ifconfig bat0 192.168.0.2

# NodeB: ping 192.168.0.1

To deactivate batman, do:

Note:  In  order to avoid problems remove all IP addresses previ-

ously assigned to interfaces now used by batman advanced, e.g.

# ifconfig eth0 0.0.0.0

VISUALIZATION

-------------

If you want topology visualization, at least one mesh  node  must

be configured as VIS-server:

# echo "server" > /sys/class/net/bat0/mesh/vis_mode

Each  node  is  either configured as "server" or as "client" (de-

fault: "client").  Clients send their topology data to the server

next to them, and server synchronize with other servers. If there

is no server configured (default) within the  mesh,  no  topology

information   will  be  transmitted.  With  these  "synchronizing

servers", there can be 1 or more vis servers sharing the same (or

at least very similar) data.

When  configured  as  server,  you can get a topology snapshot of

your mesh:

# cat /sys/class/net/bat0/mesh/vis_data

This raw output is intended to be easily parsable and convertable

with  other tools. Have a look at the batctl README if you want a

vis output in dot or json format for instance and how those  out-

puts could then be visualised in an image.

The raw format consists of comma separated values per entry where

each entry is giving information about a  certain  source  inter-

face.  Each  entry can/has to have the following values:

-> "mac" - mac address of an originator's source interface

           (each line begins with it)

-> "TQ mac  value"  -  src mac's link quality towards mac address

                       of a neighbor originator's interface which

                       is being used for routing

-> "HNA mac" - HNA announced by source mac

-> "PRIMARY" - this  is a primary interface

-> "SEC mac" - secondary mac address of source

               (requires preceding PRIMARY)

The TQ value has a range from 4 to 255 with 255 being  the  best.

The HNA entries are showing which hosts are connected to the mesh

via bat0 or being bridged into the mesh network.  The PRIMARY/SEC

values are only applied on primary interfaces

# echo "" > /proc/net/batman-adv/interfaces

LOGGING/DEBUGGING

-----------------

All error messages, warnings and information messages are sent to the

kernel log. Depending on your operating system distribution this can be

read in one of a number of ways. Try using the commands: dmesg,

logread, or looking in the files /var/log/kern.log or

/var/log/syslog. All batman-adv messages are prefixed with

All error messages, warnings and information messages are sent to

the kernel log. Depending on your operating  system  distribution

this  can  be read in one of a number of ways. Try using the com-

mands: dmesg, logread, or looking in the files  /var/log/kern.log

or  /var/log/syslog.  All  batman-adv  messages are prefixed with

"batman-adv:" So to see just these messages try

dmesg | grep batman-adv

# dmesg | grep batman-adv

When investigating problems with your mesh network it is sometimes

necessary to see more detail debug messages. This must be enabled when

compiling the batman-adv module. Use "make menuconfig" and enable the

When investigating problems with your mesh network  it  is  some-

times  necessary  to see more detail debug messages. This must be

enabled when compiling the batman-adv module. When building  bat-

man-adv  as  part of kernel, use "make menuconfig" and enable the

option "B.A.T.M.A.N. debugging".

The additional debug output is by default disabled. It can be enabled

either at kernel module load time or during run time. To enable debug

output at module load time, add the module parameter debug=<value>.

<value> can take one of four values.

The additional debug output is by default disabled. It can be en-

abled  either  at kernel modules load time or during run time. To

enable debug output at module load time, add the module parameter

debug=<value>.  <value> can take one of four values.

0 - All  debug  output  disabled

1 - Enable messages related to routing / flooding / broadcasting

e.g.

modprobe batman-adv debug=2

# modprobe batman-adv debug=2

will load the module and enable debug messages for when routes or HNAs

change.

will load the module and enable debug messages for when routes or

HNAs change.

The debug output can also be changed at runtime  using  the  file

/sys/module/batman-adv/parameters/debug. e.g.

echo 2 > /sys/module/batman-adv/parameters/debug

# echo 2 > /sys/module/batman-adv/parameters/debug

enables debug messages for when routes or HNAs

The debug output is sent to the kernel logs. So try dmesg, logread etc

to see the debug messages.

The  debug  output  is sent to the kernel logs. So try dmesg, lo-

gread, etc to see the debug messages.

BATCTL

------

B.A.T.M.A.N.  advanced operates on layer 2 and thus all hosts

participating in the virtual switch are completely transparent for all

protocols above layer 2. Therefore the common diagnosis tools do not

work as expected. To overcome these problems batctl was created. At

As batman advanced operates on layer 2 all hosts participating in

the  virtual switch are completely transparent for all  protocols

above layer 2. Therefore the common diagnosis tools do  not  work

as  expected.  To  overcome these problems batctl was created. At

the  moment the  batctl contains ping,  traceroute,  tcpdump  and

interfaces to the kernel module settings.

For more information, please see the manpage (man batctl).

batctl is available on http://www.open-mesh.net/

batctl is available on http://www.open-mesh.org/

CONTACT

-------

Please send us comments, experiences, questions, anything :)

IRC:            #batman   on   irc.freenode.org

Mailing-list:    b.a.t.m.a.n@open-mesh.net

(subscription at https://list.open-mesh.net/mm/listinfo/b.a.t.m.a.n )

Mailing-list:   b.a.t.m.a.n@open-mesh.net (optional  subscription

          at https://lists.open-mesh.org/mm/listinfo/b.a.t.m.a.n)

You can also contact the Authors:

Marek  Lindner  <lindner_marek@yahoo.de>

Simon  Wunderlich  <siwu@hrz.tu-chemnitz.de>