Routing and Switching
How to implement ARP Spoofing in NetSim?
Introduction ARP (Address Resolution Protocol) spoofing, also known as ARP poisoning, is a cyberattack where an attacker sends falsified ARP messages over a local network. This malicious activity associates the attacker’s MAC address with the IP ...
Estimating energy consumption for wireline routers in NetSim
Applicable Versions NetSim Academic NetSim Standard NetSim Pro Applicable Releases v13.3 v14.4 v15.0 NetSim supports a dedicated energy model for wireless devices in Networks such as WSN, IoT, MANETs, and VANETs. However, this is not available for ...
NetSim: Example to analyze FIFO, Priority and WFQ scheduling
Applicable Versions NetSim Standard/Acadamic NetSim Pro Applicable Release v14.4 or Higher Introduction As part of the resource allocation mechanisms, each router must implement some queuing discipline that governs how packets are buffered while ...
In NetSim, how do we configure IP addresses, subnets and applying firewall rules based on subnets?
Applicable Version All (Acad/Std/Pro) Applicable Release v13 or later In this article, we explain: What is IP addressing? How do we configure class C IP addresses in NetSim? What is a subnet? How to configure class C subnets in NetSim? Example: ...
How to calculate delay for FTP application over UDP in NetSim?
Applicable Versions NetSim Standard NetSim Professional In NetSim, the average delay for packet transmission for each application is available in the Application Metrics. During the transmission, some packets are likely to get errored or collided. ...
How to obtain a logs for ARP table updates in NetSim?
Applicable Versions NetSim Standard NetSim Pro ARP protocol implementation in NetSim is based on RFC 826. This protocol is supported in the Ethernet interface of Layer 3 devices in NetSim. The Address Resolution Protocol (ARP) is a communication ...
Understanding Static ARP configuration in NetSim
Applicable Versions NetSim Academic NetSim Standard NetSim Pro Applicable Releases v10 v11 v12 v13 In a network architecture, different layers have their own addressing scheme. The application layer uses hostnames, network layer uses IP addresses and ...
Why does the router model in NetSim have the transport layer?
Routers are layer 3 devices because they transport packets at layer 3 (mostly IP). A switch is considered a layer 2 devices because it transport frames at layer 2 (mostly Ethernet). This means they respectively must-read information in the layer 3/2 ...
Why are the source/destination IP addresses different in the logs when packets are sent across a router?
Applicable Versions NetSim Standard NetSim Pro NetSim Academic Applicable Releases v11.1 v12 v13 NetSim IP Addressing for NAT/Public IP The Source IP logged in Wireshark and packet trace is always the IP of the source All routers in NetSim are NAT ...
How to configure OSPF global and interface parameters in NetSim?
Applicable Versions NetSim Academic NetSim Standard NetSim Pro Applicable Releases v14 or Higher versions Let us consider a simple network scenario as shown below: Routers in the network have both an Ethernet interface and a WAN interface. NetSim ...
What is the OSPF default cost? How is OSPF metric value calculated in NetSim?
Applicable Versions NetSim Academic NetSim Standard NetSim Pro OSPF implementation in NetSim is based on RFC 2328. Quoting from the RFC: "The cost of sending a packet on the interface, expressed in the link state metric. This is advertised as the ...
How to change static routes over time?
This can be done using NetSim's interactive simulation feature. All commands that are supported in NetSim Device Console as part of interactive simulations, can also be passed as input to NetSim in a text file. The added advantage in this approach is ...
What is the effect of enabling/disabling static ARP in NetSim?
Applicable Versions NetSim Standard NetSim Academic NetSim Pro Applicable Releases v14.4 If STATIC ARP is enabled, it is assumed that ARP tables are updated prior to the simulation. Hence, there will be no ARP Request or ARP Reply packets exchanged ...
Why broadcast packets aren't sent across the router?
Applicable Versions NetSim Academic NetSim Standard NetSim Pro Applicable Releases v10.2 v11 v12 v13 v14 Layer 3 devices such as Routers and L3 Switches are said to be the boundary of broadcast domains and broadcast packets aren't sent across ...
How to access the rule list in the source codes of NetSim?
The Access Rule List for a specific device can be accessed using the API ACL_GET(nDeviceId), Where nDeviceId corresponds to the ID of the Device whose ACL is to be retrieved. For reference look at the function, static ACL_ACTION ...
How to configure ACL with respect to Port numbers and Protocols in NetSim?
If you have a CBR and a Voice application configured between the same two nodes, CBR follows TCP and Voice follows UDP. So you can block Voice packets by blocking UDP protocol. This is one quick and easy way of blocking protocol based packets as ...
What are the access control list options in NetSim? And where is the code for this?
Users can Permit or Deny traffic based on 1. Direction - Inbound/Outbound 2.Protocol - TCP / UDP/ IGMP / ICMP 3. Source IP Address 4. Destination IP Address 5. Source Port 6. Destination Port 7. Device Interface The source code is available in ...
How do we set up Access control lists / Firewalls with respect to IP in NetSim?
Access Control List Access control lists (ACLs) perform packet filtering to control which packets move through a network and to where. The packet filtering provides security by helping to limit the network traffic, restrict the access of users and ...
How to setup Static Route IP in NetSim?
Applicable Versions NetSim Academic Netsim Standard Netsim Pro Static Routing: Routers forward packets using either route information from route table entries that configured manually or the route information that is calculated using dynamic routing ...
Why does the switch broadcast initially when a simulation in NetSim is started ?
When the destination MAC address is a multicast or broadcast address or when the destination MAC address has not been learned by the switch (is not in its MAC addresses table) the switch will flood all the ports (except the one from which the frame ...
Why are ICMP packet sent at the start of a simulation in NetSim?
The ICMP protocol provides an echo mechanism by which a host may solicit a response from a gateway by sending message at a reasonable rate. Since the message must be sent fairly often to detect a fault in a reasonable time, it can imply an unbearable ...
Why are RIP and OSPF protocols listed under Application Layer of Router?
There is some confusion as to the exact layer in which RIP / OSPF works. It is generally taught that these works in the network layer. However, in Netsim we interpret RIP & OSPF as applications that modify the route tables. RIP runs over UDP 520 ...