3. 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.
4. 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.
7. 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
8. OPEN SHORTEST PATH FIRST
OSPF Characteristics.
OSPF Terminology
OSPF Configuration.
Verifying OSPF.
OSPF and Loopback Interfaces.
Troubleshooting OSPF.
9. 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.
10. 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.
14. OSPF TERMINOLOGY
Link-state database (topological database): A list of
information about all other routers in the internetwork. It
shows the internetwork topolog.
15. 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.
19. 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.
20. 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 10.0.0.0 0.255.255.255 area 0
21. VERIFYING OSPF
Description/FunctionCommand
Shows the entire routing tableshow 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 IDshow ip ospf database
Displays all interface-related
OSPF information.show ip ospf interface
22. 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 172.16.10.1 255.255.255.255
Router(config-if)#no shut
23. 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 10.0.0.0 255.0.0.0 area 0
RouterB#sh ip ospf interface e0/0
Ethernet0/0 is up, line protocol is up
Internet Address 172.16.1.1/16, Area 0
Process ID 2, Router ID 172.126.1.1,
Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State DR, Priority
1
Designated Router (ID) 172.16.1.1,
interface address 172.16.1.2
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 172.16.1.2/16, Area 0
Process ID 2, Router ID 172.126.1.1,
Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State DR, Priority
1
Designated Router (ID) 172.16.1.2,
interface address 172.16.1.1
No backup designated router on this
network
Timer intervals configured, Hello 5, Dead
20, Wait 20, Retransmit 5