1. RAFAT KHANDAKER
PACKET TRACER
05-15-16
ROUTING PROTOCOL
EIGRP & OSPF
.
ABSTRACT
In this lab routing protocols will be implemented inside of a simulated enterprise network
with multiple hosts. The host ranges are subnetted to provide all the hosts on the network.
EIGRP and OSPF will be configured on the 3 routers to exchange routing update tables. The
Idea of this lab is to get the basic gist of the use of routing protocols on cisco routers.
INTRODUCTION
Routing Protocols are used by routers to manage and exchange routing update tables.
Routing tables, tell the router where each host on the network are located. Different protocols for
routing have been implemented to enhance network performance. The first routing protocol was
RIP. RIP is distance vector routing protocol, It uses hop counts to determine the priority of it's
routing. RIP can only use classful network address scheme. The problem with RIP was the fact
that it's distance vector only counted for " hops " within a network and does not consider
bandwith of the link itself; in essence, RIP can completely ignore the fact that a link on the
network can use Gigabyte speed with 2 hops and route traffic through the 10mbps on 1 hop.
Another problem with RIP is scalability, when a network expand, RIP tend to congest the
badwidth because it updates it's entire routing table across the network every 30 seconds ( by
default ). EIGRP is a cisco proprietary protocol created as an enhancement to the original IGP
protocol. EIGRP allows the use of classless network addressing and use enhanced metric
calculations, which include considering the bandwidth of the link. Another advantage to EIGRP
is the fact that it allows "load balancing" meaning, that it can split the ratio of traffic between 2
links determined by their speeds. EIGRP also use a " routing by rumour " method to update it's
routing table, this way EIGRP does not need to update entire routing table; it simply summarize
it's route to another router. EIGRP is a hybrid protocol, using both properties of distance vector
and link-state. EIGRP has an instantaneous convergance. OSPF is also a widely used protocol in
enterprise networks. OSPF uses a linkstate method to exchange it's routing updates. "Link State
method " is a routing update method for stable network connectivity. The OSPF model agrees on
a routing topology within the network, when the network full converge on a topology, it only
sends update when the topology changes.
2. SIMULATION
EIGRP:
The configuration of EIGRP can only send routing tables through the use of Atonomous System.
All routers in EIGRP must have the same AS number in order to communicate it's update within
a network. Also EIGRP needs to be configured with no auto-summary, which allows the
protocol to use classless networks.
EIGRP CONFIGURATION
All routers are configured like this
after convergence, we get a message when EIGRP is properly configured.
3. show ip eigrp topology - shows full routing table
NETWORK
5. Lastly, EIGRP can also be configured for ipsummary-address, where the entire network can be
summarized. Also, EIGRP can be configured with an MD5 algorithm password to exchange
routing tables between routers. According to cisco documentation:
summary
security
6. OSPF
OSPF allows the network to be categorized into areas. In order for OSPF to communicate, the
hello and dead time intervals for all routers have to be the same. Usually, OSPF routers are
linked from a core router and are separated into where the path to the routers must go back into
the core.
In this simulation, OSPF have to be configured accordingly with all the router agreeing on the
network topology.
All routers in this simulation will be configured with router ospf 1 along with this network
topology
7. everytime a router forms an adjacency with a network we get this message
After configuration we can see from the command " show ip ospf int " that the hello and dead
intervals are set to default values. All ospf routers need to be configured with the same hello and
dead intervals in order to form an adjacency.
configuring the hello and dead intervals can be set manually through these commands on each
interface:
8. ping from pc 4
I am able to ping hosts across all three routers.
9. Conclusion
This concludes my experiment on packet tracer, where EIGRP and OSPF are configured. I have
learned a lot about both Routing protocols and the important role it play on configuring
enterprise networks.