Emulation Set-up:

The ideal set-up to run emulation would be to have a minimum of three (3) PC’s. One would be the real source, the second would run NetSim emulation server, and the third would be the real destination.

Alternately, this set-up can also be managed where the two (2) PC's are running client applications that communicate with the central server, where NetSim Emulation server is running.

Setting up the NetSim Server:

• Run NetSim in Administrative Mode (Right Click on NetSim.exe Run as Administrator).
• User has to open any Stack based Network (Any network except Legacy Networks, Wireless Sensor Network, Zigbee Network and Cellular Network) in NetSim with Emulation.
• Create a network scenario of your choice (refer application examples provided) and set the Application properties.
• In the Application Properties, set Application Type as “EMULATION”. Assign real Source IP address and Destination IP address in the respective fields. Then Click Accept.
• Set the Simulation Time as how long you want to perform the Emulation in Real World. Do not run the simulation until setting up Emulation in the Client system.

NOTE: If the Emulation Server is located in a different subnet from clients

• User has to configure the router settings of the real-world network so as to allow the packets to be transmitted to the Emulation Server

For Example, if we consider a sample real world network scenario where the Emulation clients and server are located in different subnets

• Routing table of router C needs to be configured such that any packet having Source Address as IP Address of Node 6 (Client Source) and Destination Address as IP Address of Node 8 (Client Destination) must be routed to Emulation Server. NetSim configuration will the ensure that the packet is re-injected with destination set to the appropriate IP Address (set in the application properties)

Setting up the Client systems (Real Source and Destination system)

• Open command prompt in administrative mode.
• Type command,

route delete <Network Address>

then press Enter key. You will get “OK”. For example if your IP address is 192.168.0.4 and the subnet mask is 255.255.255.0 then the network address is 192.168.0.0 (Got by performing a bitwise AND of the IP Address and the subnet mask)

• Type command

route add <Network Address>mask 255.255.255.0 <IP Address where NetSim Emulation server is running> metric 1

here the subnet mask is taken as 255.255.255.0). After execution, you will get “OK”.

• Type command

netstat –r

To check if the IP configuration is done or not.

Note that in the above screenshot, for the network 192.168.0.0, the gateway address assigned is 192.168.0.87 (Address of the system where NetSim Emulation Server is running).

Setting multiple Virtual Machines (VM) to act as Nodes for Emulation

NOTE - VM enabled license are required

VMs sharing the same network as the host.

A computer on which one or more virtual machines are running is defined as a Host Machine. Each virtual machine is called a Guest Machine. In this scenario, we have 3 VMs running in a Host Machine – VM1, VM2 and VM3. Users can run NetSim License server in any system connected to the network in which Host Machine is running.

Now right click on each VM and select Settings. Click on Network Adapter, and select “Bridged: Connected directly to the physical network”. Also enable the “Replicate Physical network connection state”.

An advantage of this technique is that, if the license server is running in another system, connected to the same network as the original host, then NetSim running in the VM can obtain the licenses.

VMs sharing a network but insulated from the host network.

A computer on which one or more virtual machines are running is defined as a Host Machine. Each virtual machine is called a Guest Machine. In this scenario, we have 3 VMs running in a Host Machine – VM1, VM2 and VM3. NetSim License server is running in one of these 3 VMs.

If user needs to create an internal network which is segregated from host network, follow the steps

1. Right click on each VM and select Settings
2. Click on Network Adapter, and select “Custom: Specific Virtual network”
3. Select “VMnet8 (NAT)”

By default, a network address is assigned to this segregated network by VMware. To configure this IP address, go to EDIT Virtual Network Editor

User can modify the Subnet IP and Subnet Mask to suit their own preference.

The disadvantage of this technique is that, if the license server must compulsorily run in the VM for NetSim to obtain the licenses.