Enhanced IGRP (EIGRP) EIGRP Characteristics. EIGRP Configuration. Verifying EIGRP.

EIGRP Characteristics Hybrid Protocol. Cisco-proprietary protocol. EIGRP works well in large networks. Default AD (administrative distance) is 90. EIGRP Metrics use a combination of (B.W, Load, Delay and Reliability) Uses an autonomous system number. Maximum Hop count is 255. Classless Routing. Support VLSM and discontiguous networks.

EIGRP Characteristics Support for IP, IPX, and AppleTalk via protocol- dependent modules Communication via Reliable Transport Protocol ( RTP ) Best path selection via Diffusing Update Algorithm ( DUAL ) Build three table: - 1.Neighbor table: Each router keeps state information about adjacent neighbors. 2.Topology table: acted upon by (DUAL). Use to determine the best path for routing packet. 3.Routing table: Store routes.

EIGRP Configuration

Configuring Discontiguous Networks Lab_A(config)#router eigrp 100 Lab_A(config-router)#no auto-summary Lab_B(config)#router eigrp 100 Lab_B(config-router)#no auto-summary

Verifying EIGRP Description/FunctionCommand Shows the entire routing table show ip route Shows only EIGRP entries in the routing table show ip route eigrp Shows all EIGRP neighbors show ip eigrp neighbors Shows entries in the EIGRP topology table show ip eigrp topology

Open Shortest Path First OSPF Characteristics. OSPF Terminology OSPF Configuration. Verifying OSPF. OSPF and Loopback Interfaces. Troubleshooting OSPF.

OSPF Characteristics Link State Protocol. Open Standard protocol. OSPF works well in large networks. Default AD (administrative distance) is 110. EIGRP Metrics use Bandwidth. Uses an autonomous system number. No Limit Hop count. Classless Routing. Support VLSM and discontiguous networks.

OSPF Characteristics Support IP only. Best path selection via Dijkstra algorithm. Manual Summarization. Build three table: - 1.Neighbor table: Each router keeps state information about adjacent neighbors. 2.Topology table: acted upon by (Dijkstra). Use to determine the best path for routing packet. 3.Routing table: Store routes.

OSPF Terminology

Link is an interface on a router. The Router ID (RID) is the highest IP address used to identify the router.

OSPF Terminology Link-State : the status of link between two routers

OSPF Terminology Link-state database (topological database): A list of information about all other routers in the internetwork. It shows the internetwork topolog.

OSPF Terminology Area: A collection of routers that has the same area identification. Each router within an area has the same link- state information. A router within an area is called an internal router.

OSPF Terminology Cost (metric): The value assigned to a link. Based on the bandwidth of the link.

OSPF Terminology Routing table: sometimes known as the forwarding database.

OSPF Terminology Adjacencies database: A listing of all the neighbors to which a router has established a bi-directional communication.

OSPF Terminology Designated router (DR) and backup designated router (BDR): A router that is elected by all other routers on the same LAN to represent all the routers. Each network has a DR and BDR.

OSPF Configuration The two basic elements of OSPF configuration: 1.Enabling OSPF. 2.Configuring OSPF areas. Router#config t Router(config)#router ospf 1 Router(config-router)#network area 0

Verifying OSPF Description/FunctionCommand Shows the entire routing table show ip route Display OSPF information for one or all OSPF processes running on the router. show ip ospf the number of links and the neighboring router’s ID show ip ospf database Displays all interface-related OSPF information. show ip ospf interface

OSPF and Loopback Interfaces Configuring loopback interfaces when using the OSPF routing protocol is important, and Cisco suggests using them whenever you configure OSPF on a router. Loopback interfaces are logical interfaces, which are virtual, software-only interfaces; they are not real router interfaces. Configuring Loopback Interfaces Router (config)#int loopback 0 Router (config-if)#ip address Router(config-if)#no shut

Troubleshooting OSPF What is the error in this configuration if you want to route only ip packet begin with 10 then any number ? Router(config)#router ospf 1 Router(config-router)#network area 0 RouterB#sh ip ospf interface e0/0 Ethernet0/0 is up, line protocol is up Internet Address /16, Area 0 Process ID 2, Router ID , Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) , interface address No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 RouterA#sh ip ospf interface e0/0 Ethernet0/0 is up, line protocol is up Internet Address /16, Area 0 Process ID 2, Router ID , Network Type BROADCAST, Cost: 10 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) , interface address No backup designated router on this network Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5