Configuring OSPF Default Route Propagation

command(s);

area # network netmask – This command is executed in OSPF router configuration mode to advertise the default route as a type 5 LSA to 0.0.0.0/0.

default-information originate always – This command is executed in OSPF router configuration mode to advertise the default route as a type 3 summary LSA to 0.0.0.0/0.

The following logical topology shown below is used in labs found through out Section 9 – Configuring OSPF;

Lab Prerequisites

• If you completed lab 9-14 you can start where you’ve left off or you can load the Free CCNA Workbook GNS3 topology; start and establish a console session with R1, R2, R3, R4, R5 and SW1 then load their initial configurations included below by copying the config from the textbox and pasting it into the routers console.

Initial Configurations

!################################################## !#  Free CCNA Workbook Lab 9-15 R1 Initial Config # !################################################## ! enable configure terminal ! hostname R1 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.10.1 255.255.255.0  ip ospf 1 area 1 ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.1 255.255.255.248  ip ospf 1 area 0  encapsulation frame-relay  serial restart-delay 0  frame-relay map ip 10.1.245.5 125 broadcast  frame-relay map ip 10.1.245.4 124 broadcast  frame-relay map ip 10.1.245.2 122 broadcast  no frame-relay inverse-arp  no shut  exit ! router ospf 1  router-id 1.1.1.1  log-adjacency-changes  auto-cost reference-bandwidth 100000  maximum-paths 1  neighbor 10.1.245.2  neighbor 10.1.245.4  neighbor 10.1.245.5 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-15 R2 Initial Config # !################################################## ! enable configure terminal ! hostname R2 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.20.1 255.255.255.0  ip ospf 1 area 2 ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.2 255.255.255.248  encapsulation frame-relay  ip ospf priority 0 ip ospf 1 area 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 221 broadcast  frame map ip 10.1.245.4 221  frame map ip 10.1.245.5 221  no shut ! interface Serial1/2  ### POINT-TO-POINT LINK TO R3 ###  ip address 10.1.23.1 255.255.255.252  ip ospf 1 area 3  ip ospf hello-interval 1  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  router-id 2.2.2.2  auto-cost reference-bandwidth 100000  log-adjacency-changes  area 3 stub no-summary ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-15 R3 Initial Config # !################################################## ! enable configure terminal ! hostname R3 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.30.1 255.255.255.0  ip ospf 1 area 3 ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R2 ###  ip address 10.1.23.2 255.255.255.252  ip ospf 1 area 3  ip ospf hello-interval 1  encapsulation ppp  no shut  exit ! router ospf 1  router-id 3.3.3.3  log-adjacency-changes  auto-cost reference-bandwidth 100000  area 3 stub ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-15 R4 Initial Config # !################################################## ! enable configure terminal ! hostname R4 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.40.1 255.255.255.0  ip ospf 1 area 4 ! interface Loopback4  description ### SIMULATED NETWORK ###  ip address 10.44.4.1 255.255.255.0  ip ospf 1 area 44 ! interface Loopback5  description ### SIMULATED NETWORK ###  ip address 10.44.5.1 255.255.255.0  ip ospf 1 area 44 ! interface Loopback6  description ### SIMULATED NETWORK ###  ip address 10.44.6.1 255.255.255.0  ip ospf 1 area 44 ! interface Loopback7  description ### SIMULATED NETWORK ###  ip address 10.44.7.1 255.255.255.0  ip ospf 1 area 44 ! interface FastEthernet0/0  description ### REAL NETWORK ###  ip address 10.45.1.1 255.255.255.0  ip ospf 1 area 45  no shut ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.4 255.255.255.248  encapsulation frame-relay  ip ospf priority 0  ip ospf 1 area 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 421 broadcast  frame map ip 10.1.245.2 421  frame map ip 10.1.245.5 421  no shut ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R5 ###  ip address 10.1.45.1 255.255.255.252  ip ospf 1 area 45  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  router-id 4.4.4.4  auto-cost reference-bandwidth 100000  log-adjacency-changes  passive-interface fastethernet0/0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-15 R5 Initial Config # !################################################## ! enable configure terminal ! hostname R5 no ip domain-lookup ! interface Loopback0  description ### SIMULATED NETWORK ###  ip address 10.55.50.1 255.255.255.0  ip ospf 1 area 5 ! interface FastEthernet0/0  description ### REAL NETWORK ###  ip address 10.45.1.2 255.255.255.0  ip ospf cost 65535  ip ospf 1 area 45  no shut ! interface Serial1/0  description ### PHYSICAL FRAME RELAY INTERFACE ###  ip address 10.1.245.5 255.255.255.248  encapsulation frame-relay  ip ospf priority 0  ip ospf 1 area 0  serial restart-delay 0  no frame-relay inverse-arp  frame map ip 10.1.245.1 521 broadcast  frame map ip 10.1.245.2 521  frame map ip 10.1.245.4 521  no shut ! interface Serial1/1  description ### POINT-TO-POINT LINK TO R4 ###  ip address 10.1.45.2 255.255.255.252  ip ospf 1 area 45  encapsulation ppp  serial restart-delay 0  no shut  exit ! router ospf 1  router-id 5.5.5.5  log-adjacency-changes  auto-cost reference-bandwidth 100000  passive-interface fastethernet0/0 ! line con 0  logging sync  no exec-timeout ! end

!################################################## !#  Free CCNA Workbook Lab 9-X SW1 Initial Config # !################################################## ! enable configure terminal ! hostname SW1 no ip domain-lookup ! line con 0  logging sync  no exec-timeout ! end

Lab Objectives

• Configure R1 to always originate a default route through out the entire OSPF autonomous system.
• Verify that the default route is being propagated correctly by viewing the routing table on R4.

Lab Instruction

Objective 1. – Configure R1 to always originate a default route through out the entire OSPF autonomous system.

R1#configure terminal Enter configuration commands, one per line. End with CNTL/Z. R1(config)#router ospf 1 R1(config-router)#default-information originate always R1(config-router)#end R1#

Objective 2. – Verify that the default route is being propagated correctly by viewing the routing table on R4.

R4#show ip route
Codes: C - connected, S - static, 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
      i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
      ia - IS-IS inter area, * - candidate default, U - per-user static route
      o - ODR, P - periodic downloaded static route

Gateway of last resort is 10.1.245.1 to network 0.0.0.0

    10.0.0.0/8 is variably subnetted, 15 subnets, 5 masks
O IA    10.55.50.1/32 [110/64767] via 10.1.245.5, 00:54:52, Serial1/0
C       10.55.40.0/24 is directly connected, Loopback0
O IA    10.1.23.0/30 [110/129532] via 10.1.245.2, 00:54:52, Serial1/0
C       10.44.6.0/24 is directly connected, Loopback6
C       10.44.7.0/24 is directly connected, Loopback7
O IA    10.55.30.1/32 [110/129533] via 10.1.245.2, 00:26:12, Serial1/0
C       10.44.4.0/24 is directly connected, Loopback4
O       10.44.4.0/22 is a summary, 00:54:52, Null0
C       10.44.5.0/24 is directly connected, Loopback5
C       10.1.45.2/32 is directly connected, Serial1/1
C       10.45.1.0/24 is directly connected, FastEthernet0/0
C       10.1.45.0/30 is directly connected, Serial1/1
O IA    10.55.20.1/32 [110/64767] via 10.1.245.2, 00:54:53, Serial1/0
O IA    10.55.10.1/32 [110/64767] via 10.1.245.1, 00:54:53, Serial1/0
C       10.1.245.0/29 is directly connected, Serial1/0
O*E2 0.0.0.0/0 [110/1] via 10.1.245.1, 00:00:17, Serial1/0
R4#