NetSim – Advanced Routing

Overview

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 –

Switching:

Virtual LAN (VLAN) Protocol per IEEE 802.1Q

  • VLAN Tagging, VLAN ID and VLAN Name
  • Access and Trunk Ports
  • Inter VLAN routing
  • VLAN Configuration through GUI or Text file

Detailed L3 Switch Model

  • Switching Techniques
  • Spanning tree protocol and multiple spanning tree instances per switch
  • Unicast, Broadcast and Multicast switching
  • Promiscuous mode

Routing:

Internet Group Management Protocol (IGMP) per RFC 2236

  • IGMP Message - Query, Report
  • Host State Machine and Router State Machine

IP Multicasting

  • Host extensions for IP multicasting per RFC 1112
  • IP route tables based on multicast application in host
  • IP route tables changed as per matched bit count

Access Control List(ACL):

  • ACL Action – Permit ,Deny
  • ACL Direction- Inbound, Outbound, Both
  • Protocol wise permit blocking
  • Interface Id blocking
  • Source and destination IP Address
  • Source and destination port numbers

Protocol Independent Multicast (PIM), Sparse mode per RFC 7761

  • Shortest Path Tree
  • (*, G) State
  • (S, G) State
  • Designated Router Election
  • Hello Timer, Join Expiry Timer

Network Address Translation (NAT) and Public IP

  • Public IP of Host from WAN Router

Routing Protocols:

  • RIP (Routing Interior Protocol )
    • Update Timer
    • Timeout Timer
    • Garbage Collection Timer
  • OSPF(Open Shortest Path First)
    • LSRefresh Time

Queuing discipline in Router

  • First-in-first-out (FIFO) queuing
  • Round Robin
  • Priority queuing (PQ)
  • Weighted-fair queuing (WFQ)

Border Gateway Protocol(BGP):

BGP (Border Gateway Protocol) is protocol that manages how packets are routed across the internet through the exchange of routing and reachability information betweeneadge routers. BGP directs packets between autonomous systems (AS) -- networks managed by a single enterprise or service provider. Traffic that is routed within a single network AS is referred to as internal BGP, or iBGP. More often, BGP is used to connect one AS to other autonomous systems, and it is then referred to as an external BGP, or eBGP

  • Autonomous systems (AS) Number
  • ocal Preference
  • ExtRouteAdvInterval
  • IntRouteAdvInterval

International Standards Used in Advanced Routing:

IETF RFC’s 1771 & 3121, RFC 2236, RFC 1112, RFC 7761

Virtual LAN (VLAN) Configuration in NetSim:

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

  • VLAN Tagging, VLAN ID and VLAN Name
  • Access and Trunk Ports
  • VLAN Configuration through GUI or Text file
  • Inter VLAN routing

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.

  • Shortest Path Tree
  • Hello Timer, Join Expiry Timer
  • (*, G) State
  • (S, G) State
  • Designated Router Election

PIM Configuration:

ACL (Access control lists) Configuration in NetSim:

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.

  • ACL Action – Permit ,Deny
  • ACL Direction- Inbound, Outbound, Both
  • Protocol wise permit blockingx
  • Interface Id blocking
  • Source and destination IP Address
  • Source and destination port numbers

ACL Configuration:

Network address translation (NAT) Configuration in NetSim:

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.

Wireshark Interfacing for Router: pcap files can be recorded at each node which can be opened in Wireshark for protocol analysis

Additional Information:

Knowledgebase Q&A
File Exchange Link
Webinar Links