Introduction to networking Dynamic routes
Jan 17, 2016
Introduction to networking
Dynamic routes
Objectives Define dynamic routing and its properties Describe the classes of routing protocols Describe the basic router configuration
commands for protocols
Dynamic routing overview Dynamic routing allow routers to learn about remote
networks fro mother routers and update their own routing tables with new information
Dynamic routing is necessary to allow networks to update and adapt quickly to changes
The success depends on the maintenance of a routing table and timely distribution of knowledge
Dynamic routing depends on routing protocols which describe: How to send updates What knowledge is contained in these updates When to send this knowledge How to locate recipients of the updates
Administrative distance is used to determine the preferred source of routing updates
Routing protocols
Identifying the classes of interior gateway routing protocols
Determines direction, or vector (exit interface), and Distance (metric) to any link in the internetwork
Recreates the exact topology of theentire internetnetwork
Distance vector
Each router receives a routing table from its directly connected neighbour routers.The distance vector algorithm (Bellman-Ford) does not allow a router to know the exact topology of an internetwork since each router only sees its neighbor routers.
Distance vector network discovery
The interface that leads to each directly connected network has a distance of 0
Distance vector network discovery
An analogy of distance vector could be the signs found at a highway intersection. A sign points toward a destination and indicates the distance to the destination. Further down the highway, another sign points toward the destination, but now the distance is shorter. As long as the distance is shorter, the traffic is on the best path.
Link state routing protocol features
Link-state advertisement (LSA) - a small packet of routing information that is sent between routers Topological database - a collection of information gathered from LSAs SPF algorithm - a calculation performed on the database that results in the SPF tree Routing table - a list of the known paths and interfaces
Consists of allLSA’s
Shortest path calculations
Link state topology changes
Link state concerns
Routing configuration
GAD(config)#router rip GAD(config-router)#network 172.16.0.0
IP network number of directly connected network
Configure EIGRP To configure EIGRP on a router
router(config)#router eigrp autonomous-system router(config)#router eigrp 1
An autonomous system is a collection of networks under a common administrative control
EIGRP uses a autonomous system number, but calls this a process ID
The process ID essentially refers to an instance of the protocol running on a router
All the routers running in the same routing domain that are using EIGRP must have the same process ID in order to communicate
Configure EIGRP with a network address router(config)#router eigrp 1 router(config)#network 172.16.0.0
Summary Dynamic routing scales better to larger, more
complex networks They involve more complex protocols that
demand a greater knowledge of networking
Questions... ...are there any?