USING OSPF ROUTING SIMULATION OF DATA TRAFFIC CONTROL
USING OSPF ROUTING
SIMULATION OF DATA TRAFFIC CONTROL
Objective
To design a network for a software development organization based on OSPF. The organization has three departments, development, testing and trainee and a high speed internet connection. The trainee department should not have access to internet browsing, but all other communication should be allowed on the internet. The users in all the departments should have inter-access communication with each other. All the departments should be on different IP networks.
Requirements
Design different area of the network.Core knowledge of subnet mask and wild
mask. Cisco based routers and switches to be used. Identify the configurations required on the
routers and switches for the open routing protocol.
Introduction to computer networks
Three types of networksLAN: privately owned and links the devices in a
single office, building, or campus.MAN: designed to extend over an entire city. It
may be single network such as a cable television network, or it may be a means of connecting a number of LANs into a larger network
WAN: provides long-distance transmission of data, image, audio, and video information over large geographic areas that may comprise a country, a continent, or even the whole world
Classes of Routing Protocols
Routing protocol is used between router to determine paths and maintaining the routing tables. Processes for sharing route information allow routers to communicate with other routers to update and maintain the routing tables.RIP, IGRP, OSPF, BGP,And EIGRP
Comparing Routing Protocols
DISTANCE VECTOR ROUTING
LINK STATE ROUTING
a) View network topology from neighbor’s perspective.
b) Adds distance vector from router to router.
c) Frequent periodic updates.
Slow convergence.
d) Passes copies of routing table to neighbor router.
a) Gets common view of entire network topology.
b) Calculate the shortest path of other router.
c) Event-triggered updates.
Fast convergence.
d) Passes link-state routing updates to other router.
Routing Information Protocol
RIP adheres to the following Distance Vector characteristics:RIP sends out periodic routing updates (every
30 seconds).RIP sends out the full routing table every
periodic update.RIP uses a form of distance as its metric (in
this case, hopcount of 15).RIP uses the Bellman-Ford Distance Vector
algorithm to determine the best “path” to a particular destination.
Version 1 (RIPv1) and Version 2 (RIPv2).
RIPv1
RIPv2
• Classful
• Does not include the subnet mask with its routing table updates
• Does not support Variable Length Subnet Masks (VLSMs)
• Networks must be contiguous, and subnets of a major network must be configured with identical subnet masks
• Sends updates as broadcasts to address 255.255.255.255
• Classless
• Does include the subnet mask with its routing table updates
• RIPv2 fully supports VLSMs
• Discontinuous networks and varying subnet masks can exist.
• Routing updates are sent via multicast, using address 224.0.0.9
OSPF (Open Shortest Path First) Routing Protocol
The Open Shortest Path First or OSPF protocol is an intra-domain routing protocol based on link state routing. Its domain is also an autonomous system. To handle routing efficiently and in a timely manner, OSPF divides an autonomous system into areas. An area is a collection of networks, hosts, and routers all contained within an autonomous system. All the areas must be connected with each other.
An Autonomous System
Types of links
Point-to-point: one router attached to the otherTransient: network with several routers attached to itStub: a network that is connected to only one router. Link is only one-directional, from the router to the networkVirtual: When the link between two routers is broken, the administration may create a virtual link between them, using a longer path that probably goes through several routers.
Various Links
OSPF and RIP Comparison
Characteristics
OSPF
RIPv1
RIPv2
Type of protocol
Link State Distance Vector
Distance Vector
Classless Support
Yes Yes No
VLSM Support
Yes Yes No
Route Propagation
Multicast on change
Periodic multicast
Periodic Broadcast
Path Matric
Bandwidth
Hops
Hops
Hop count limit
None 15 15
Convergence
Fast Slow Slow
Access Control List
ACLs are lists of conditions that are applied to traffic traveling across a router's interface.
These lists tell the router what types of packets to accept or deny based on some conditions
ACLs can be configured at the router to control access to a network or subnet.
Some ACL decision points are source and destination addresses, protocols, and upper-layer port numbers.
Reasons to Create ACLs
Limit network traffic and increase network performance.
Provide traffic flow control. Provide a basic level of security for network access. Decide which types of traffic are forwarded or
blocked at the router interfacesFor example: Permit e-mail traffic to be routed, but
block all telnet traffic. There are of two typesStandardExtended
CASE STUDY
The Tata Steel Company has all Cisco routers connected in the network. The network administrator Robert requires configuring the router of the HR Department to disable the traffic from all the host of the subnet 1272.168.2.6 from the Network 40.0.0.1 and for 20.0.0.2 host for security purpose and the company has web secure and the organization want only the specific department users can access the web server.Problem: Network administrator already configures the
organization network than he has to again configure the access-list as per requirement.
Solution: Firstly we will draw a network on packet tracer. According to the requirement of the administrator.
Problem Scenario
RIP OVER OSPF
Network Area of OSPF
The following are the reasons for creating OSPF in a hierarchical design:To decrease routing overheadTo speed up convergenceTo confine network instability to single area of
the network.OSPF must have an area 0 or BACKBONE, and all other areas should connect to this area. There are various kinds of routers like: internal, boundary area, etc. and various areas like: boundary, regular, stub areas, etc.
OSPF OVER RIP
Implementing ACLs
Now we will implement the Extended ACL for Blocking the Server for the particular host on Router 0.
Router#enRouter#conf tEnter configuration commands, one per line. End with CNTL/Z.Router(config)#access-list 100 deny tcp host 20.0.0.2 host
172.167.2.6 eq 80Router(config)#access-list 100 permit tcp any anyRouter(config)#access-list 100 permit icmp any anyRouter(config)#int fastEthernet 7/0Router(config-if)#ip access-group 100 inRouter(config-if)#no shutRouter(config-if)#exRouter#%SYS-5-CONFIG_I: Configured from console by console
Continued
Now we will implement the Extended ACL for Blocking the Server for the particular Network on Router 0.
Router#enRouter#conf tEnter configuration commands, one per line. End with CNTL/Z.Router(config)#access-list 100 deny tcp host 40.0.0.1 host
172.167.2.6 eq 80Router(config)#access-list 100 permit tcp any anyRouter(config)#access-list 100 permit icmp any anyRouter(config)#int fastEthernet 0/0Router(config-if)#ip access-group 100 inRouter(config-if)#no shutRouter(config-if)#exRouter#%SYS-5-CONFIG_I: Configured from console by console