NetSim is a discrete event simulator covering a broad range of wired, wireless, mobile and sensor networks. It comes with a simple and user friendly GUI which features drag and drop functionality for devices, links, application etc.
The specifications for the Advanced Routing module are –
Internet Control Message Protocol (ICMP) per RFC 792
Access Control List(ACL):
Protocol Independent Multicast (PIM), Sparse mode per RFC 7761
Network Address Translation (NAT) and Public IP
Queuing discipline in Router
IETF RFC’s 1771 & 3121, RFC 2236, RFC 1112, RFC 7761, RFCs 792, 777, 760
VLAN is called as virtual local area network, used in Switches and it operates at layer2 and Layer3. A VLAN, is a group of hosts which communicate as if they were attached to the same broadcast domain, regardless of their physical location
For example, all workstations and servers used by a particular workgroup team can be connected to the same VLAN, regardless of their physical connections to the network or the fact that they might be intermingled with other teams. VLANs have the same attributes as physical LANs, but you can group end stations even if they are not physically located on the same LAN segment.
IETF RFC’s 1771 & 3121, RFC 2236, RFC 1112, RFC 7761
Protocol Independent Multicast (PIM) Configuration in NetSim:
PIM is used between routers so that they can track which multicast packets to forward to each other and to their directly connected LANs.
Routers provide basic traffic filtering capabilities, such as blocking Internet traffic, with access control lists (ACLs). An ACL is a sequential list of permit or deny statements that apply to addresses or upper-layer protocols.
An access list is a sequential series of commands or filters. These lists tell the router what types of packets to: permit or deny. When using an access-list to filter traffic, a permit statement is used to “allow” traffic, while a deny statement is used to “block” traffic.
NAT (Network Address Translation or Network Address Translator) is the virtualization of Internet Protocol (IP) addresses. NAT helps to improve security and decrease the number of IP addresses an organization needs.
A device that is configured with NAT will have at least one interface to the inside network and one to the outside network. In a typical environment, NAT is configured at the exit device between a stub domain (inside network) and the backbone. When a packet leaves the domain, NAT translates the locally significant source address into a globally unique address. When a packet enters the domain, NAT translates the globally unique destination address into a local address. If more than one exit point exists, each NAT must have the same translation table. NAT can be configured to advertise to the outside world only one address for the entire network. This ability provides additional security by effectively hiding the entire internal network behind that one address. If NAT cannot allocate an address because it has run out of addresses, it drops the packet and sends an Internet Control Message Protocol (ICMP) host unreachable packet to the destination.
Routers forward packets using either route information from route table entries that configured manually or the route information that is calculated using dynamic routing algorithms. Static routes, which define explicit paths between two routers, cannot be automatically updated; you must manually reconfigure static routes when network changes occur. Static routes use less bandwidth than dynamic routes.
Static routes are used in environments where network traffic is predictable and where the network design is simple. You should not use static routes in large, constantly changing networks because static routes cannot react to network changes. Most networks use dynamic routes to communicate between routers but might have one or two static routes configured for special cases.
Static IP Routing Configuration: