The ns Manual (formerly ns Notes and Documentation)1 - NM Lab at ...

40.2 ConfigurationTo set up simulation scenario, we first build the detailed network. We also need to create one extra node to represent theabstract network, and connect it to the detailed network.For nodes in the detailed network, we first attach a MessagePassing agent to each node:set a [new Agent/MessagePassing]$n attach $a $probing_portIf the node represents a vulnerable host, we use class DnhWormAppset w [new Application/Worm/Dnh]$w attach-agent $aOtherwise, we configure the node as invulnerable:set w [new Application/Worm]$w attach-agent $aWe configure the abstract network as:set a [new Agent/MessagePassing]$na attach $a $probing_portset w [new Application/Worm/An]$w attach-agent $aIn order for the abstract network to receive probing packets generated by nodes within the detailed networks, we need to usemanual routing. There are some extra configuration for the abstract-network node:set p [$na set dmux_]$p defaulttarget $a[$na entry] defaulttarget $p40.3 Commands at a glanceSome common parameters can be configured through TCL script:ScanRate # the rate that a compromised host sends probing packetsScanPort # the vulnerable service port numberScanPacketSize # the size of worm probing packetsBy default, compromised hosts scan the Internet randomly. We can also simulate local-scanning worm by setting the localscanningprobability:361