Kernel AODV GatewayingLuke Klein-BerndtNational Institute of Standards and Technologyhttp://w3.antd.nist.gov/wctg/aodv_kernel/----------------------------------------------------Managed Internet Gatewaying:In this mode there are two different types of nodes, Gateway Nodes and ClientNodes. A Gateway node requires two interfaces, one which hooked up to the normalnetwork and another which will connect to the AODV network. The Client issimply a regular AODV node which has been configured with the correct setting tocommunicate on the network which the Gateway node is attached to. This meansthat a client node should have the same DNS settings as a Gateway node. Thesesetting can usaully be accessed through the netconf program.A Gateway node should be configured should that it can communication with theexternal network. This means it non-AODV interface should have a correctlyconfigured IP address. The correctly route towards the subnet gateway of theexternal network should also be configured. It is also important to make surethat the subnets of the two interfaces do not overlap.The Gateway node will generate a Route Reply to all Route Request which are notin the AODV subnet. The Gateway node considers the AODV subnet to be equivlantto the subnet settings for the interface being used by AODV. So if the interfaceis configured for 192.168.1.34/255.255.255.0, AODV would consider everythingfrom 192.168.1.0 - 192.168.1.255 to be part of the AODV subnet. Of course allof the Client nodes have to be configured so that their IP address isin this subet. The Gateway node assumes every address in the AODV subnet can berouted by AODV and all other addresses can be routed locally through the routingtable.IPTABLES is used to do NAT, allowing AODV nodes to access the externalnetwork, even if their IP address is not externally routable. IPTABLES shouldbe installed on the Gateway node.After a Client node's network settings have been correctly configured it isstarted using './start.sh'. Before a Gateway node can be started, its startupscript must first be edited. Edit start_gateway.sh to reflect your currentnetwork configuration. Once that is done you should be ready to go!For example:   Node A - the gatewaying nodes            eth0- connected to internet	          IP= 129.6.53.50	    eth1- WLAN connected to other AODV nodes		  IP= 129.6.230.5   Node B - AODV node	  eth0- connected to other AODV nodes		IP=129.6.230.4   The AODV subnet in this example would be 129.6.230	Also make sure /proc/sys/net/route/min_delay is set to zero. This is the timethat changes to the routing table are cached before being written. If it is notzero, crazy things happen... crazy things...Created: 11/05/01 Updated: 03/01/04NIST is an agency of the U.S. Commerce Department's Technology Administration