Howto: Ad-hoc networks with Mobilemesh - Ubuntu Forums

Howto: Ad-hoc networks with Mobilemesh - Ubuntu Forums

Howto: Ad-hoc networks with Mobilemesh

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If you want to create an mobile ad-hoc mesh network with several nodes that are able to dynamically alter paths to find each other, then this is for you. See http://www.mitre.org/work/tech_transfer/mobilemesh/ for more information.

This guide charts the method I used to set up a small test network of three nodes sharing an Internet connection. If you have any problems or difficulties please post them below. Most of this guide uses a terminal for issuing commands, when it comes to editing files I have mentioned gedit, but there is no other dependence on GNOME. I have tested this guide on Ubuntu 6.10 (Edgy) i386 only. All systems were fully up-to-date as of 26 January 2007. Please make sure that you have the Universe repository enabled before you begin.

Step 1: What you will need
In order to run mobilemesh you will need at least one network card that is already setup and known to be working. If you are going to use wireless then please ensure you have a driver that works, I have tested this only on madwifi and an NDISwrapped Broadcom card (v1.33).

Wired/Infrastructure mode
Mobilemesh does work on wired/infrastructure networks quite happily, but it won't take advantage of the dynamic routing.

Ad-hoc mode
If you want to use ad-hoc mode then so far I have come accross three scenarios
(i) Some cards, such as those running ndiswrapper, should work simply by changing the interface into ad-hoc mode.

Code:

sudo iwconfig wlan0 mode ad-hoc

(ii) At the moment the bcm43xx driver does not support ad-hoc mode with the kernel's softmac stack, so you will have to replace it with the new dscape stack or switch to ndiswrapper.
(ii) For madwifi you will need to create a VAP in adhoc mode with the wlanconfig tool. Unfortunately Ubuntu doesn't include wlanconfig by default, so you will have to build madwifi from source. There may be a way to build just the tools, but I haven't found it yet.

Step 2: Install
Before you enable adhoc mode you will first need to download and install some software. Mobilemesh is packaged and ready for Edgy in the Universe repository. You can get it through Synaptic or at a terminal with

Code:

sudo apt-get install mobilemesh

Alternatively you can download the package and install off-line. All dependencies are included on a default install of Ubuntu.
After installation I found that it didn't create the /var/run/mobilemesh directory. So I had to create it manually.

Code:

sudo mkdir /var/run/mobilemesh

Step 3: Enable connections
Assuming you have the interface in adhoc mode, you will need to attach it to an ssid (with WEP encryption).

Code:

sudo ifconfig wlan0 up sudo iwconfig wlan0 essid mobilemesh sudo iwconfig wlan0 key 012345678910

Next you will need to assign the interface an ip address. Here we will use local-link addresses, replace the Xs with any unique combination of numbers (1-255).

Code:

sudo ifconfig wlan0 169.254.X.X

You should now have an adhoc network and be able to ping directly with other nodes that are in range.

Step 4: Configure
Take note of the interface names you will be using, e.g. eth0, eth1, wlan0 etc. These need to added to the /etc/mobilemesh/mmrp.conf.

Code:

gksudo gedit /etc/mobilemesh/mmrp.conf

It should look something like this

Code:

# # Config File for Mobile Mesh Routing Protocol #  # This file is used to: #   1) Specify configuration parameters for the routing protocol: #        port          #        alpha        , where (1.0 <= value <= 2.0)  #        minTxDelay    #        maxTxDelay    #        updatePeriod  #        maxAge        # #   2) Specify the interfaces that will participate in the MMRP  #        interface   # #   3) Specify external routes that should be advertised within the MMRP cloud #        external    # #  port 20471 alpha 1.0 minTxDelay 1 maxTxDelay 4 maxAge 20 updatePeriod 4  interface wlan0         # <- Change/add interface here  #external 0.0.0.0 0.0.0.0 7  # Don't delete this line!

If you want to advertise an external internet connection then uncomment the external line, first making sure you have turned on ip forwarding and masquerading or setup firestarter.

Step 5: Enable Mobilemesh
Each interface you want to use will need to have an mmdiscover daemon attached to it.

Code:

sudo mmdiscover -i wlan0

Finally start mmrp to manage the routing protocols.

Code:

sudo mmrp

To check that it is up and working, view the kernel routing table.

Code:

ip route

Step 6: Uninstallation
To bring down the mobilemesh daemons you can kill them directly.

Code:

sudo killall mmrp sudo killall mmdiscover

Mobilemesh can be uninstalled through synaptic or apt.

Troubleshooting
A. First time through I found it useful to append the -z switch to check for error messages.
B. Check that you have named each of the interfaces to be used in the /etc/mobilemesh/mmrp.conf file and that they each have an instance of the mmdiscover daemon attached to them.
C. Remove any interfaces from the /etc/mobilemesh/mmrp.conf file that are not being used by mobilemesh.
D. Run tcpdump or wireshark to catch packets as they are sent between nodes.
E. If you have difficulty changing the interfaces to ad-hoc mode or changing the wireless network settings, it might be a good idea to comment out the relevant sections of the /etc/network/interfaces file. Be sure not to delete this file or alter the Lo interface.
F. According to the information I gathered mobilemesh is a set of userspace tools, so it shouldn't need root privilege. However, when trying to run as a normal user it complains about access to certain root owned files. This is why I have chosen to run all commands as root, though I'm not sure if this presents a security risk.

Credits
Thanks to Mitre for creating this software tool and releasing it under an open source license. Also, thanks go to the Debian and MotU teams for packaging Mobilemesh.