issues in single area ospf as the size of the network increases there will be large number of lsas...

Issues in Single area OSPF

• As the size of the network increases there will be

large number of LSAs flooded in the network,

which is a overhead to the Routers.

• The routing table will become extremely large.

Advantage of Multiple-Area

• Extensive control of routing updates.

• Defining areas reduce routing overhead.

• Speedup convergence.

• Confines network instability to one area.

• Improves performance.

OSPF - Network Diagram

LAN - 192.168.1.0/24 LAN – 192.168.2.0/24 LAN - 192.168.3.0/24

E0 192.168.1.1/24

E0 192.168.2.1/24

E0 192.168.3.1/24

10.0.0.1/8S0

S110.0.0.2/8

11.0.0.1/8S0

S111.0.0.2/8

Area 0

Area 1 Area 2

HYD CHE BAN

exitHyderabad(config-if)#Hyderabad(config)#

telnet 192.168.1.1

================================Welcome to Hyderabad Router================================User Access Verificationpassword :****

****enable

configure terminal

interface serial 0ip address 10.0.0.1 255.0.0.0no shutclockrate 64000encapsulation hdlc

Hyderabad>password :Hyderabad#Enter configuration commands, one per line. End with CNTL/Z.Hyderabad(config)#Hyderabad(config-if)#Hyderabad(config-if)#Hyderabad(config-if)#Hyderabad(config-if)#

Microsoft Windows 2000 [Version 5.00.2195](C) Copyright 1985-2000 Microsoft Corp.C:\>Connecting .....

Directly Connected Networks on HYDERABAD Router

192.168.1.010.0.0.0

Directly Connected Networks on HYDERABAD Router

192.168.1.010.0.0.0

Hyderabad(config)#router ospf 1

Hyderabad(config-router)#

Hyderabad(config-router)# network 192.168.1.0 0.0.0.255 area 1Hyderabad(config-router)# network 10.0.0.0 0.255.255.255 area 1

no ip routingHyderabad(config)#

Hyderabad(config)#ip routing

Configuring OSPFRouter(config)# router ospf <pid>Router(config-router)# network <Network ID> <wildcard mask> area <area id>


show ip routeHyderabad#Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i- IS-IS, L1-IS-IS level-1, L2-IS-IS level-2,*- candidate default U - per-user static route, o - ODR

Gateway of last resort is not set

C 10.0.0.0/8 is directly connected, Serial0O IA 11.0.0.0/8 [110/128] via 10.0.0.2, 00:01:03, Serial0C 192.168.1.0/24 is directly connected, Ethernet0O IA 192.168.2.0/24 [110/74] via 10.0.0.2, 00:01:03, Serial0O IA 192.168.3.0/24 [110/138] via 10.0.0.2, 00:00:13, Serial0Hyderabad#

^Z

O IA – for OSPF Inter Area routes


110 is nothing but Administrative Distance


Metric of OSPF Cost

Metric of OSPF Cost

Hyderabad(config)#router ospf 1

Hyderabad(config-router)#

Hyderabad(config-router)# network 192.168.1.0 0.0.0.255 area 1Hyderabad(config-router)# network 10.0.0.0 0.255.255.255 area 1

no ip routingHyderabad(config)#

Hyderabad(config)#ip routing

show ip ospf databaseHyderabad#

OSPF Router with ID (192.168.1.1) (Process ID 1)

Router Link States (Area 1)

Link ID ADV Router Age Seq# Checksum Link 192.168.1.1 192.168.1.1 272 0x80000003 0xA163 3192.168.2.1 192.168.2.1 273 0x80000002 0xBACC 2

Summary Net Link States (Area 1)

Link ID ADV Router Age Seq# Checksum11.0.0.0 192.168.2.1 273 0x80000001 0xDA15192.168.2.0 192.168.2.1 273 0x80000001 0x8441192.168.3.0 192.168.2.1 208 0x80000001 0xFB88Hyderabad# show ip ospf neighbor

Neighbor ID Pri State Dead Time Address192.168.2.1 1 FULL/ - 00:00:32 10.0.0.2Hyderabad#

Chennai(config-if)#Chennai(config-if)#

================================Welcome to Chennai Router================================User Access Verificationpassword :****

****enable

configure terminal

ip address 10.0.0.2 255.0.0.0no shutencapsulation hdlcinterface serial 0

Chennai>password :Chennai#Enter configuration commands, one per line. End with CNTL/Z.Chennai(config)#Chennai(config-if)#Chennai(config-if)#Chennai(config-if)#Chennai(config-if)#


Chennai(config-if)#

telnet 192.168.2.1

interface serial 1

ip address 11.0.0.1 255.0.0.0no shutencapsulation hdlc

Directly Connected Networks on CHENNAI Router192.168.2.0

10.0.0.011.0.0.0

Directly Connected Networks on CHENNAI Router192.168.2.0

10.0.0.011.0.0.0

Chennai(config)#router ospf 2

Chennai(config-router)#

Chennai(config-router)# network 192.168.2.0 0.0.0.255 area 0Chennai(config-router)# network 10.0.0.0 0.255.255.255 area 1

no ip routingChennai(config)#

Chennai(config)#ip routing

network 11.0.0.0 0.255.255.255 area 2Chennai(config-router)#



show ip routeChennai#Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i- IS-IS, L1-IS-IS level-1, L2-IS-IS level-2,*- candidate default U - per-user static route, o - ODR


C 10.0.0.0/8 is directly connected, Serial1C 11.0.0.0/8 is directly connected, Serial0O 192.168.1.0/24 [110/74] via 10.0.0.1, 00:01:04, Serial1C 192.168.2.0/24 is directly connected, Ethernet0O 192.168.3.0/24 [110/74] via 11.0.0.2, 00:00:09, Serial0Chennai#

^Z

O – for OSPF routes O – for OSPF routes 110 is nothing but Administrative Distance


Metric of OSPF Cost

Metric of OSPF Cost

Chennai(config)#router ospf 2

Chennai(config-router)#

Chennai(config-router)# network 192.168.2.0 0.0.0.255 area 0Chennai(config-router)# network 10.0.0.0 0.255.255.255 area 1

no ip routingChennai(config)#

Chennai(config)#ip routing

network 11.0.0.0 0.255.255.255 area 2Chennai(config-router)#

show ip ospf databaseChennai#



Link ID ADV Router Age Seq# Checksum Link 192.168.2.1 192.168.2.1 472 0x80000002 0xEFC7 1


Link ID ADV Router Age Seq# Checksum10.0.0.0 192.168.2.1 462 0x80000001 0xE70911.0.0.0 192.168.2.1 472 0x80000001 0xDA15192.168.1.0 192.168.2.1 452 0x80000001 0x1274192.168.3.0 192.168.2.1 396 0x80000001 0xFB88


Link ID ADV Router Age Seq# Checksum Link 192.168.1.1 192.168.1.1 463 0x80000003 0xA163 3192.168.2.1 192.168.2.1 462 0x80000002 0xBACC 2--More—-


Link ID ADV Router Age Seq# Checksum11.0.0.0 192.168.2.1 462 0x80000001 0xDA15192.168.2.0 192.168.2.1 465 0x80000001 0x8441192.168.3.0 192.168.2.1 400 0x80000001 0xFB88


Link ID ADV Router Age Seq# Checksum Link 192.168.2.1 192.168.2.1 415 0x80000003 0xDAA8 2192.168.3.1 192.168.3.150 416 0x80000003 0xD328 3


Link ID ADV Router Age Seq# Checksum10.0.0.0 192.168.2.1 465 0x80000001 0xE709192.168.1.0 192.168.2.1 455 0x80000001 0x1274192.168.2.0 192.168.2.1 475 0x80000001 0x8441Chennai# show ip ospf neighborNeighbor ID Pri State Dead Time Address192.168.3.1 1 FULL/ - 00:00:35 11.0.0.2192.168.1.1 1 FULL/ - 00:00:32 10.0.0.1Chennai#

exitBanglore(config-if)#Banglore(config)#

================================Welcome to Banglore Router================================User Access Verificationpassword :****

****enable

configure terminal

ip address 11.0.0.2 255.0.0.0no shutclockrate 64000encapsulation hdlc

Banglore>password :Banglore#Enter configuration commands, one per line. End with CNTL/Z.Banglore(config)#Banglore(config-if)#Banglore(config-if)#Banglore(config-if)#Banglore(config-if)#


telnet 192.168.3.1

interface serial 1

Directly Connected Networks on Banglore Router192.168.3.0

11.0.0.0

Directly Connected Networks on Banglore Router192.168.3.0

11.0.0.0

Banglore(config)#router ospf 1

Banglore(config-router)#

Banglore(config-router)# network 192.168.3.0 0.0.0.255 area 2Banglore(config-router)#

no ip routingBanglore(config)#

Banglore(config)#ip routing

network 11.0.0.0 0.255.255.255 area 2



show ip routeBanglore#Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP i- IS-IS, L1-IS-IS level-1, L2-IS-IS level-2,*- candidate default U - per-user static route, o - ODR


O IA 10.0.0.0/8 [110/128] via 11.0.0.1, 00:02:26, Serial1C 11.0.0.0/8 is directly connected, Serial1O IA 192.168.1.0/24 [110/138] via 11.0.0.1, 00:02:26, Serial1O IA 192.168.2.0/24 [110/74] via 11.0.0.1, 00:02:26, Serial1C 192.168.3.0/24 is directly connected, Ethernet0Banglore#

^Z





Metric of OSPF Cost

Metric of OSPF Cost

Banglore(config)#router ospf 1

Banglore(config-router)#

Banglore(config-router)# network 192.168.3.0 0.0.0.255 area 2Banglore(config-router)#

no ip routingBanglore(config)#

Banglore(config)#ip routing

network 11.0.0.0 0.255.255.255 area 2

show ip ospf databaseBanglore#



Link ID ADV Router Age Seq# Checksum Link 192.168.2.1 192.168.2.1 935 0x80000003 0xDAA8 2192.168.3.1 192.168.3.1 934 0x80000003 0xD328 3


Link ID ADV Router Age Seq# Checksum10.0.0.0 192.168.2.1 985 0x80000001 0xE709192.168.1.0 192.168.2.1 975 0x80000001 0x1274192.168.2.0 192.168.2.1 995 0x80000001 0x8441Banglore#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address192.168.2.1 1 FULL/ - 00:00:36 11.0.0.1Banglore#

ping 192.168.3.10Hyderabad#Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.3.1, timeout is 2 seconds:

Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msHyderabad#

!!!!!

ping 192.168.2.10Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.2.1, timeout is 2 seconds:

Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msHyderabad#

!!!!!

ping 192.168.1.10Chennai#Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:

Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msChennai#

!!!!!


Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msChennai#

!!!!!

ping 192.168.1.10Banglore#Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.1.1, timeout is 2 seconds:

Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msBanglore#

!!!!!


Success rate is 100 percent (5/5), round-trip min/avg/max = 40/43/44 msBanglore#

!!!!!

issues in single area ospf as the size of the network increases there will be large number of lsas...

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