OSPFv2 Issue between two Router

Andrew guory009 · ‎03-14-2025

I am completing an OSPF troubleshooting exercise, but I have no idea how to solve the problem, because I need to get some help, which can be either advice or solutions.

My understanding of this problem is that I guess the network unavailable is not caused by ospf, because R2 and R3 both exist in the ospf neighbor of each other, and R3 in the ip route table of R2 is connected by OSPF. Strangely, R2 does not exist in OSPF in R3's ip route table. And since only R2 can ping to R3, no other device can, I was very curious and wondering what could have caused the situation of both connecting and preventing other devices from accessing the broadcast domain. Thanks for reading.

Best Regards,

Andrew

The following content is the original configuration, I did not make any modification and repair measures, is the most original state after the error

R1

R1#show ip route 
Codes: L - local, 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, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

S*    0.0.0.0/0 is directly connected, Loopback0
      10.0.0.0/8 is variably subnetted, 9 subnets, 2 masks
C        10.0.1.0/24 is directly connected, GigabitEthernet0/0/1
L        10.0.1.1/32 is directly connected, GigabitEthernet0/0/1
O        10.0.2.0/24 [110/2] via 10.0.1.2, 01:30:15, GigabitEthernet0/0/1
O IA     10.1.1.0/24 [110/2] via 10.0.1.2, 01:30:15, GigabitEthernet0/0/1
O IA     10.1.2.0/24 [110/2] via 10.0.1.2, 01:30:15, GigabitEthernet0/0/1
O IA     10.1.3.0/24 [110/2] via 10.0.1.2, 01:30:15, GigabitEthernet0/0/1
C        10.2.0.0/24 is directly connected, GigabitEthernet0/0/0
L        10.2.0.1/32 is directly connected, GigabitEthernet0/0/0
O        10.2.1.0/24 [110/2] via 10.2.0.2, 01:30:20, GigabitEthernet0/0/0
      64.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        64.100.10.0/24 is directly connected, Loopback0
L        64.100.10.1/32 is directly connected, Loopback0
R1#sh
R1#show run
R1#show running-config 
Building configuration...


Current configuration : 2018 bytes
!
! Last configuration change at 03:54:34 UTC Sat Mar 15 2025
!
version 16.9
service timestamps debug datetime msec
service timestamps log datetime msec
platform qfp utilization monitor load 80
no platform punt-keepalive disable-kernel-core
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
vrf definition Mgmt-intf
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!
!
no aaa new-model
!
!
!
!
!
!
!
no ip domain lookup
!
!
!
login on-success log
!
!
!
!
!
!
!
subscriber templating
! 
! 
! 
! 
vtp domain MawsonLakes
vtp mode transparent
!
multilink bundle-name authenticated
!
!
!
!
!
!
license udi pid ISR4331/K9 sn FDO24160G4X
license accept end user agreement
license boot suite FoundationSuiteK9
no license smart enable
diagnostic bootup level minimal
!
spanning-tree extend system-id
!
!         
!
!
redundancy
 mode none
!
!
!
!
!
!
!
! 
!
!
!
!
!
!
!
!
!
!
!         
! 
!
!
interface Loopback0
 ip address 64.100.10.1 255.255.255.0
!
interface GigabitEthernet0/0/0
 ip address 10.2.0.1 255.255.255.0
 negotiation auto
!
interface GigabitEthernet0/0/1
 ip address 10.0.1.1 255.255.255.0
 negotiation auto
!
interface GigabitEthernet0/0/2
 no ip address
 negotiation auto
!
interface Serial0/1/0
 no ip address
!
interface Serial0/1/1
 no ip address
!
interface Serial0/2/0
 no ip address
!
interface Serial0/2/1
 no ip address
!
interface GigabitEthernet0
 vrf forwarding Mgmt-intf
 no ip address
 negotiation auto
!
router ospf 1
 router-id 1.1.1.1
 network 10.0.1.0 0.0.0.255 area 0
 network 10.2.0.0 0.0.0.255 area 2
 default-information originate always
!
!
!
ip forward-protocol nd
no ip http server
ip http secure-server
ip tftp source-interface GigabitEthernet0
ip route 0.0.0.0 0.0.0.0 Loopback0
!
!
!
!
!
!
control-plane
!
banner motd ^C This is R1, Trouble Ticket 8.1.2.3 ^C
alias exec reset.now tclsh flash:/enarsi/reset.tcl
!
line con 0
 exec-timeout 0 0
 logging synchronous
 transport input none
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!         
!
!
!
!
!
end

R2

R2#show ip route 
Codes: L - local, 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, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 10.2.0.1 to network 0.0.0.0

O*E2  0.0.0.0/0 [110/1] via 10.2.0.1, 01:21:19, GigabitEthernet0/0/0
      10.0.0.0/8 is variably subnetted, 12 subnets, 2 masks
O IA     10.0.1.0/24 [110/2] via 10.2.0.1, 01:21:19, GigabitEthernet0/0/0
O IA     10.0.2.0/24 [110/3] via 10.2.0.1, 01:21:14, GigabitEthernet0/0/0
O IA     10.1.1.0/24 [110/3] via 10.2.0.1, 01:21:14, GigabitEthernet0/0/0
O IA     10.1.2.0/24 [110/3] via 10.2.0.1, 01:21:14, GigabitEthernet0/0/0
O IA     10.1.3.0/24 [110/3] via 10.2.0.1, 01:21:14, GigabitEthernet0/0/0
C        10.2.0.0/24 is directly connected, GigabitEthernet0/0/0
L        10.2.0.2/32 is directly connected, GigabitEthernet0/0/0
C        10.2.1.0/24 is directly connected, Loopback0
L        10.2.1.1/32 is directly connected, Loopback0
C        10.3.0.0/24 is directly connected, GigabitEthernet0/0/1
L        10.3.0.2/32 is directly connected, GigabitEthernet0/0/1
O        10.3.1.0/24 [110/2] via 10.3.0.1, 01:21:21, GigabitEthernet0/0/1
R2#sh
R2#show run
R2#show running-config 
Building configuration...


Current configuration : 2127 bytes
!
! Last configuration change at 03:44:49 UTC Sat Mar 15 2025
!
version 16.9
service timestamps debug datetime msec
service timestamps log datetime msec
platform qfp utilization monitor load 80
no platform punt-keepalive disable-kernel-core
!
hostname R2
!
boot-start-marker
boot-end-marker
!
!
vrf definition Mgmt-intf
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!
!
no aaa new-model
!
!
!
!
!
!
!
no ip domain lookup
!
!
!
login on-success log
!
!
!
!
!
!
!
subscriber templating
! 
! 
! 
! 
vtp domain merger.com.au
vtp mode transparent
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!         
!
license udi pid ISR4331/K9 sn FDO24160G6G
license boot suite FoundationSuiteK9
license boot level uck9
no license smart enable
diagnostic bootup level minimal
!
spanning-tree extend system-id
!
!
!
!
redundancy
 mode none
!
!
!
!
!
!
!
! 
!         
!
!
!
!
!
!
!
!
!
! 
! 
!
!
interface Loopback0
 ip address 10.2.1.1 255.255.255.0
 ip ospf network point-to-point
!
interface GigabitEthernet0/0/0
 ip address 10.2.0.2 255.255.255.0
 negotiation auto
!
interface GigabitEthernet0/0/1
 ip address 10.3.0.2 255.255.255.0
 negotiation auto
!
interface GigabitEthernet0/0/2
 no ip address
 negotiation auto
!
interface Serial0/1/0
 no ip address
!
interface Serial0/1/1
 no ip address
!
interface GigabitEthernet0
 vrf forwarding Mgmt-intf
 no ip address
 negotiation auto
!
router ospf 1
 router-id 2.2.2.2
 network 10.2.0.0 0.0.0.255 area 2
 network 10.2.1.0 0.0.0.255 area 2
 network 10.3.0.0 0.0.0.255 area 3
!         
ip forward-protocol nd
no ip http server
ip http secure-server
ip tftp source-interface GigabitEthernet0
!
!
!
!
!
!
control-plane
!
!
mgcp behavior rsip-range tgcp-only
mgcp behavior comedia-role none
mgcp behavior comedia-check-media-src disable
mgcp behavior comedia-sdp-force disable
!
mgcp profile default
!
!
!
!         
!
banner motd ^C This is R2, Trouble Ticket 8.1.2.3 ^C
alias exec reset.now tclsh flash:/enarsi/reset.tcl
!
line con 0
 exec-timeout 0 0
 logging synchronous
 transport input none
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
!
!
!
!
!
end

R3

R3#show ip route 
Codes: L - local, 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, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      10.0.0.0/8 is variably subnetted, 4 subnets, 2 masks
C        10.3.0.0/24 is directly connected, GigabitEthernet0/0/0
L        10.3.0.1/32 is directly connected, GigabitEthernet0/0/0
C        10.3.1.0/24 is directly connected, Loopback0
L        10.3.1.1/32 is directly connected, Loopback0

R3#show running-config 
Building configuration...


Current configuration : 1977 bytes
!
! Last configuration change at 04:10:44 UTC Sat Mar 15 2025
!
version 16.9
service timestamps debug datetime msec
service timestamps log datetime msec
platform qfp utilization monitor load 80
no platform punt-keepalive disable-kernel-core
!
hostname R3
!
boot-start-marker
boot-end-marker
!
!
vrf definition Mgmt-intf
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!
!
no aaa new-model
!
!
!
!
!
!
!
no ip domain lookup
!
!
!
login on-success log
!
!
!
!
!
!
!
subscriber templating
! 
! 
! 
! 
vtp domain KiteNet
vtp mode transparent
!
multilink bundle-name authenticated
!
!
!
!
!
!
license udi pid ISR4331/K9 sn FDO24160HVS
license boot suite FoundationSuiteK9
no license smart enable
diagnostic bootup level minimal
!
spanning-tree extend system-id
!
!
!         
!
redundancy
 mode none
!
!
!
!
!
!
!
! 
!
!
!
!
!
!
!
!
!
!
! 
!         
!
!
interface Loopback0
 ip address 10.3.1.1 255.255.255.0
 ip ospf network point-to-point
!
interface GigabitEthernet0/0/0
 ip address 10.3.0.1 255.255.255.0
 negotiation auto
!
interface GigabitEthernet0/0/1
 ip address 10.0.3.1 255.255.255.0
 shutdown
 negotiation auto
!
interface GigabitEthernet0/0/2
 no ip address
 negotiation auto
!
interface Serial0/1/0
 no ip address
!
interface Serial0/1/1
 no ip address
!
interface Serial0/2/0
 no ip address
!
interface Serial0/2/1
 no ip address
!
interface GigabitEthernet0
 vrf forwarding Mgmt-intf
 no ip address
 negotiation auto
!
router ospf 1
 router-id 3.3.3.3
 network 10.0.3.0 0.0.0.255 area 0
 network 10.3.0.0 0.0.0.255 area 3
 network 10.3.1.0 0.0.0.255 area 3
!
ip forward-protocol nd
no ip http server
ip http secure-server
ip tftp source-interface GigabitEthernet0
!
!
!
!
!
!
control-plane
!
banner motd ^C This is R3, Trouble Ticket 8.1.2.3 ^C
alias exec reset.now tclsh flash:/enarsi/reset.tcl
!
line con 0
 exec-timeout 0 0
 logging synchronous
 transport input none
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
!
!
!         
!
!
!
end

D1

D1#show ip route 
Codes: L - local, 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, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 10.0.1.1 to network 0.0.0.0

O*E2  0.0.0.0/0 [110/1] via 10.0.1.1, 01:31:11, GigabitEthernet1/0/11
      10.0.0.0/8 is variably subnetted, 12 subnets, 2 masks
C        10.0.1.0/24 is directly connected, GigabitEthernet1/0/11
L        10.0.1.2/32 is directly connected, GigabitEthernet1/0/11
C        10.0.2.0/24 is directly connected, Port-channel1
L        10.0.2.1/32 is directly connected, Port-channel1
C        10.1.1.0/24 is directly connected, Port-channel2
L        10.1.1.1/32 is directly connected, Port-channel2
C        10.1.2.0/24 is directly connected, GigabitEthernet1/0/23
L        10.1.2.1/32 is directly connected, GigabitEthernet1/0/23
C        10.1.3.0/24 is directly connected, GigabitEthernet1/0/24
L        10.1.3.1/32 is directly connected, GigabitEthernet1/0/24
O IA     10.2.0.0/24 [110/2] via 10.0.1.1, 01:31:11, GigabitEthernet1/0/11
O IA     10.2.1.0/24 [110/3] via 10.0.1.1, 01:31:11, GigabitEthernet1/0/11
D1#sh
D1#show rn
D1#show run
D1#show running-config 
Building configuration...

Current configuration : 9559 bytes
!
! Last configuration change at 03:53:05 UTC Sat Mar 15 2025
!
version 16.9
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
! Call-home is enabled by Smart-Licensing.
service call-home
no platform punt-keepalive disable-kernel-core
!
hostname D1
!
!
vrf definition Mgmt-vrf
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!         
!         
no aaa new-model
switch 1 provision ws-c3650-24ps
!
!
!
!
call-home
 ! If contact email address in call-home is configured as sch-smart-licensing@cisco.com
 ! the email address configured in Cisco Smart License Portal will be used as contact email address to send SCH notifications.
 contact-email-addr sch-smart-licensing@cisco.com
 profile "CiscoTAC-1"
  active
  destination transport-method http
  no destination transport-method email
ip routing
!
!
!
!
!
no ip domain lookup
!
!
!
login on-success log
!
!
!
!
!
!
!
!
crypto pki trustpoint TP-self-signed-3240170804
 enrollment selfsigned
 subject-name cn=IOS-Self-Signed-Certificate-3240170804
 revocation-check none
 rsakeypair TP-self-signed-3240170804
!
crypto pki trustpoint SLA-TrustPoint
 enrollment pkcs12
 revocation-check crl
!
!         
crypto pki certificate chain TP-self-signed-3240170804
 certificate self-signed 01
  30820330 30820218 A0030201 02020101 300D0609 2A864886 F70D0101 05050030 
  31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274 
  69666963 6174652D 33323430 31373038 3034301E 170D3235 30333135 30333437 
  31305A17 0D333030 31303130 30303030 305A3031 312F302D 06035504 03132649 
  4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D33 32343031 
  37303830 34308201 22300D06 092A8648 86F70D01 01010500 0382010F 00308201 
  0A028201 0100D38A 3A92AED7 66AEB374 B751040A A994AC94 D95C380C 413501E8 
  86A7906A 58581D84 6B793B02 1D868084 A7BDE45C 6FB26BCB A4BFC949 C2AA30D1 
  C753958A 5D9FC3B1 3A7A14E0 0FF7BE73 B8956687 023D34B6 A655B20A 8E5D0E26 
  6E48B207 1C13F00F B8D21F73 75294357 D37386BB 695D018B 673A9958 E65D1129 
  15726898 1647BD44 381A3CB1 25BE3DE3 D7784A59 4A74EA5E 5A506800 3DC7ACE2 
  A1A9B442 B6F0A2AB AB04D3B7 AEFF5B3D A4C1FC21 BCF5B18D 34D16C5B 6D34731F 
  663FA4E4 2ED9A408 2E05F029 CB1FC9B6 4E1E1B46 E0E3244E D39CFB4B 83786AB6 
  E7908B6D AEA0AC39 0F42E73C 8C7CDA1D 0EE835E3 1A1FB01F DA05D677 C2FA3284 
  CFA7F34F 357B0203 010001A3 53305130 0F060355 1D130101 FF040530 030101FF 
  301F0603 551D2304 18301680 14FDD880 2B6EA873 F1BA2865 DCDB4A7B 3D3459B4 
  0F301D06 03551D0E 04160414 FDD8802B 6EA873F1 BA2865DC DB4A7B3D 3459B40F 
  300D0609 2A864886 F70D0101 05050003 82010100 0DBF3414 85A6BF89 FAEF5E7B 
  539E1247 4285891C 48A87717 D312199B 5B8652D2 2AA1668A 525AF6CF 5F0C1D6D 
  043AA81B 9DC28CC5 A486AD78 AEDFFB3A 90E4C21B FC5F2CA8 E2F1FEA8 AA49ED56 
  E3286155 390EA47E D0F2103C 4FC2532A 3F96BC6F 99A83F34 D040CED8 117D047A 
  F3D88C91 7E9905D4 8452660A FE1217F1 EEE02352 4FF888BF 1100BC28 7FE0429C 
  D22015D9 26AFD479 5C666781 DF846CEC B12F0A4B 86EFFB10 E1610EF1 20460B73 
  80092624 8DCF77B3 BFDE1BB8 84148C5D E9781E65 F9CFBFD6 05B6D152 54F7F055 
  85534C2B 9C1B380E E015E848 5B03A3D3 67E621F5 78422B0E BAE8DE0F 156F4D4F 
  0F852CF7 984AD8F1 2B00F87A BF75A0A8 59669733
        quit
crypto pki certificate chain SLA-TrustPoint
 certificate ca 01
  30820321 30820209 A0030201 02020101 300D0609 2A864886 F70D0101 0B050030 
  32310E30 0C060355 040A1305 43697363 6F312030 1E060355 04031317 43697363 
  6F204C69 63656E73 696E6720 526F6F74 20434130 1E170D31 33303533 30313934 
  3834375A 170D3338 30353330 31393438 34375A30 32310E30 0C060355 040A1305 
  43697363 6F312030 1E060355 04031317 43697363 6F204C69 63656E73 696E6720 
  526F6F74 20434130 82012230 0D06092A 864886F7 0D010101 05000382 010F0030 
  82010A02 82010100 A6BCBD96 131E05F7 145EA72C 2CD686E6 17222EA1 F1EFF64D 
  CBB4C798 212AA147 C655D8D7 9471380D 8711441E 1AAF071A 9CAE6388 8A38E520 
  1C394D78 462EF239 C659F715 B98C0A59 5BBB5CBD 0CFEBEA3 700A8BF7 D8F256EE 
  4AA4E80D DB6FD1C9 60B1FD18 FFC69C96 6FA68957 A2617DE7 104FDC5F EA2956AC 
  7390A3EB 2B5436AD C847A2C5 DAB553EB 69A9A535 58E9F3E3 C0BD23CF 58BD7188 
  68E69491 20F320E7 948E71D7 AE3BCC84 F10684C7 4BC8E00F 539BA42B 42C68BB7 
  C7479096 B4CB2D62 EA2F505D C7B062A4 6811D95B E8250FC4 5D5D5FB8 8F27D191 
  C55F0D76 61F9A4CD 3D992327 A8BB03BD 4E6D7069 7CBADF8B DF5F4368 95135E44 
  DFC7C6CF 04DD7FD1 02030100 01A34230 40300E06 03551D0F 0101FF04 04030201 
  06300F06 03551D13 0101FF04 05300301 01FF301D 0603551D 0E041604 1449DC85 
  4B3D31E5 1B3E6A17 606AF333 3D3B4C73 E8300D06 092A8648 86F70D01 010B0500 
  03820101 00507F24 D3932A66 86025D9F E838AE5C 6D4DF6B0 49631C78 240DA905 
  604EDCDE FF4FED2B 77FC460E CD636FDB DD44681E 3A5673AB 9093D3B1 6C9E3D8B 
  D98987BF E40CBD9E 1AECA0C2 2189BB5C 8FA85686 CD98B646 5575B146 8DFC66A8 
  467A3DF4 4D565700 6ADF0F0D CF835015 3C04FF7C 21E878AC 11BA9CD2 55A9232C 
  7CA7B7E6 C1AF74F6 152E99B7 B1FCF9BB E973DE7F 5BDDEB86 C71E3B49 1765308B 
  5FB0DA06 B92AFE7F 494E8A9E 07B85737 F3A58BE1 1A48A229 C37C1E69 39F08678 
  80DDCD16 D6BACECA EEBC7CF9 8428787B 35202CDC 60E4616A B623CDBD 230E3AFB 
  418616A9 4093E049 4D10AB75 27E86F73 932E35B5 8862FDAE 0275156F 719BB2F0 
  D697DF7F 28
        quit
!
license boot level ipservicesk9
!
!
diagnostic bootup level minimal
!
spanning-tree mode rapid-pvst
spanning-tree extend system-id
!
!
!         
redundancy
 mode sso
!
!
!
!
!
transceiver type all
 monitoring
!
!
class-map match-any system-cpp-police-topology-control
  description Topology control
class-map match-any system-cpp-police-sw-forward
  description Sw forwarding, L2 LVX data, LOGGING
class-map match-any system-cpp-default
  description Inter FED, EWLC control, EWLC data
class-map match-any system-cpp-police-sys-data
  description Learning cache ovfl, High Rate App, Exception, EGR Exception, NFL SAMPLED DATA, RPF Failed
class-map match-any system-cpp-police-punt-webauth
  description Punt Webauth
class-map match-any system-cpp-police-l2lvx-control
  description L2 LVX control packets
class-map match-any system-cpp-police-forus
  description Forus Address resolution and Forus traffic
class-map match-any system-cpp-police-multicast-end-station
  description MCAST END STATION
class-map match-any system-cpp-police-multicast
  description Transit Traffic and MCAST Data
class-map match-any system-cpp-police-l2-control
  description L2 control
class-map match-any system-cpp-police-dot1x-auth
  description DOT1X Auth
class-map match-any system-cpp-police-data
  description ICMP redirect, ICMP_GEN and BROADCAST
class-map match-any system-cpp-police-stackwise-virt-control
  description Stackwise Virtual
class-map match-any non-client-nrt-class
class-map match-any system-cpp-police-routing-control
  description Routing control and Low Latency
class-map match-any system-cpp-police-protocol-snooping
  description Protocol snooping
class-map match-any system-cpp-police-dhcp-snooping
  description DHCP snooping
class-map match-any system-cpp-police-system-critical
  description System Critical and Gold Pkt
!
policy-map system-cpp-policy
!
! 
!
!
!
!
!
!
!
!
!
interface Port-channel1
 no switchport
 ip address 10.0.2.1 255.255.255.0
!
interface Port-channel2
 no switchport
 ip address 10.1.1.1 255.255.255.0
!
interface GigabitEthernet0/0
 vrf forwarding Mgmt-vrf
 no ip address
 shutdown
 negotiation auto
!
interface GigabitEthernet1/0/1
 description Channel to D2
 no switchport
 no ip address
 channel-group 1 mode on
!
interface GigabitEthernet1/0/2
 description Channel to D2
 no switchport
 no ip address
 channel-group 1 mode on
!
interface GigabitEthernet1/0/3
 description Channel to D2
 no switchport
 no ip address
 channel-group 2 mode on
!         
interface GigabitEthernet1/0/4
 description Channel to D2
 no switchport
 no ip address
 channel-group 2 mode on
!
interface GigabitEthernet1/0/5
 shutdown
!
interface GigabitEthernet1/0/6
 shutdown
!
interface GigabitEthernet1/0/7
 shutdown
!
interface GigabitEthernet1/0/8
 shutdown
!
interface GigabitEthernet1/0/9
 shutdown
!
interface GigabitEthernet1/0/10
 shutdown 
!
interface GigabitEthernet1/0/11
 no switchport
 ip address 10.0.1.2 255.255.255.0
!
interface GigabitEthernet1/0/12
 shutdown
!
interface GigabitEthernet1/0/13
 shutdown
!
interface GigabitEthernet1/0/14
 shutdown
!
interface GigabitEthernet1/0/15
 shutdown
!
interface GigabitEthernet1/0/16
 shutdown
!
interface GigabitEthernet1/0/17
 shutdown
!         
interface GigabitEthernet1/0/18
 shutdown
!
interface GigabitEthernet1/0/19
 shutdown
!
interface GigabitEthernet1/0/20
 shutdown
!
interface GigabitEthernet1/0/21
 shutdown
!
interface GigabitEthernet1/0/22
 shutdown
!
interface GigabitEthernet1/0/23
 no switchport
 ip address 10.1.2.1 255.255.255.0
!
interface GigabitEthernet1/0/24
 no switchport
 ip address 10.1.3.1 255.255.255.0
!         
interface GigabitEthernet1/1/1
!
interface GigabitEthernet1/1/2
!
interface GigabitEthernet1/1/3
!
interface GigabitEthernet1/1/4
!
interface Vlan1
 no ip address
 shutdown
!
router ospf 1
 router-id 4.4.4.4
 network 10.0.1.0 0.0.0.255 area 0
 network 10.0.2.0 0.0.0.255 area 0
 network 10.1.1.0 0.0.0.255 area 1
 network 10.1.2.0 0.0.0.255 area 1
 network 10.1.3.0 0.0.0.255 area 1
!
ip forward-protocol nd
ip http server
ip http authentication local
ip http secure-server
!
!
!
!
!
!
control-plane
 service-policy input system-cpp-policy
!
banner motd ^C This is D1, Trouble Ticket 8.1.2.3 ^C
alias exec reset.now tclsh flash:/enarsi/reset.tcl
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
line vty 5 15
 login    
!
!
!
!
!
!
!
end

D2

D2#show ip route 
Codes: L - local, 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, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is 10.0.2.1 to network 0.0.0.0

O*E2  0.0.0.0/0 [110/1] via 10.0.2.1, 01:31:58, Port-channel1
      10.0.0.0/8 is variably subnetted, 9 subnets, 2 masks
O        10.0.1.0/24 [110/2] via 10.0.2.1, 01:32:07, Port-channel1
C        10.0.2.0/24 is directly connected, Port-channel1
L        10.0.2.2/32 is directly connected, Port-channel1
C        10.1.1.0/24 is directly connected, Port-channel2
L        10.1.1.2/32 is directly connected, Port-channel2
O        10.1.2.0/24 [110/2] via 10.1.1.1, 01:32:02, Port-channel2
O        10.1.3.0/24 [110/2] via 10.1.1.1, 01:32:02, Port-channel2
O IA     10.2.0.0/24 [110/3] via 10.0.2.1, 01:31:58, Port-channel1
O IA     10.2.1.0/24 [110/4] via 10.0.2.1, 01:31:58, Port-channel1
D2#   sh
D2#   show run
D2#   show running-config 
Building configuration...

Current configuration : 9409 bytes
!
! Last configuration change at 03:30:14 UTC Sat Mar 15 2025
!
version 16.9
no service pad
service timestamps debug datetime msec
service timestamps log datetime msec
! Call-home is enabled by Smart-Licensing.
service call-home
no platform punt-keepalive disable-kernel-core
!
hostname D2
!
!
vrf definition Mgmt-vrf
 !
 address-family ipv4
 exit-address-family
 !
 address-family ipv6
 exit-address-family
!         
!         
no aaa new-model
switch 1 provision ws-c3650-24ps
!
!
!
!
call-home
 ! If contact email address in call-home is configured as sch-smart-licensing@cisco.com
 ! the email address configured in Cisco Smart License Portal will be used as contact email address to send SCH notifications.
 contact-email-addr sch-smart-licensing@cisco.com
 profile "CiscoTAC-1"
  active
  destination transport-method http
  no destination transport-method email
ip routing
!
!
!
!
!
no ip domain lookup
!
!
!
login on-success log
!
!
!
!
!
!
!
!
crypto pki trustpoint TP-self-signed-1351620958
 enrollment selfsigned
 subject-name cn=IOS-Self-Signed-Certificate-1351620958
 revocation-check none
 rsakeypair TP-self-signed-1351620958
!
crypto pki trustpoint SLA-TrustPoint
 enrollment pkcs12
 revocation-check crl
!
!         
crypto pki certificate chain TP-self-signed-1351620958
 certificate self-signed 01
  30820330 30820218 A0030201 02020101 300D0609 2A864886 F70D0101 05050030 
  31312F30 2D060355 04031326 494F532D 53656C66 2D536967 6E65642D 43657274 
  69666963 6174652D 31333531 36323039 3538301E 170D3235 30333135 30333234 
  32365A17 0D333030 31303130 30303030 305A3031 312F302D 06035504 03132649 
  4F532D53 656C662D 5369676E 65642D43 65727469 66696361 74652D31 33353136 
  32303935 38308201 22300D06 092A8648 86F70D01 01010500 0382010F 00308201 
  0A028201 010091C1 4E815258 1A3DD854 1DFBB7E4 CBCCAA31 AE4C93C6 7535FC20 
  62941C99 3B4DD4B4 FCEC6B99 320D289F 07A9FE7C 8F81B5EE 001F0B4B 668EA709 
  A2FEA9C3 1A335FAC 4082BF08 E886EABB 2DD7E6FF 5D97C154 FB464E2F 4283078A 
  72EAF5D1 19AAB001 142714F0 D3014932 3A960CBB EA2684FC 3277E09C 3C0C467A 
  D43FE82D 81CBEA15 D1C245C9 7B9CFB8B CC33C7DB 3ED16F47 01CEBFC6 1B4B001F 
  AC1098FD 0BF4BFA6 EDCBD530 7849331F 3E682AF5 539E5024 F3CD15AE CD01E957 
  4D7C52C0 6BB7EE39 AC1AE052 7F7ED456 619D3216 4E2712E1 83121821 6F1865FA 
  10281EF0 FD406506 21F19EE9 3A458341 C3BE9821 2217399D D00A7DCE C0137076 
  20BA7F29 9E4B0203 010001A3 53305130 0F060355 1D130101 FF040530 030101FF 
  301F0603 551D2304 18301680 145A51EB 2DA6407F 04B9F9D2 3521125A 3392F021 
  D3301D06 03551D0E 04160414 5A51EB2D A6407F04 B9F9D235 21125A33 92F021D3 
  300D0609 2A864886 F70D0101 05050003 82010100 87A2D52A E87B1F64 C064EFEC 
  72190475 2F80AC6A 827F3A2D C06BB361 5B6A3A16 8222FA32 F16372F3 CA6CFC3E 
  A04480C0 F60DCA06 12BA1729 F5B11E4A 36081FB1 7DAC1994 9F86D8E2 90391725 
  06DE65D2 75A6FC4A 3C952494 B2F2E3B3 B53BDFFB 6ECCDD92 937DA881 F8FCF645 
  9B942C51 A4837486 AF370AA9 33543A5A 03033028 43FF857A 1599835A 533E951A 
  4E3D72FB 20C6A13C 9C036D3D 78AB06A6 577E2CD8 1447734F F56A1E6A D058A3E7 
  0FE1FBB8 F10BB0B9 F4BCB35D 842583AD 16C01616 DE96868A 60A57D19 DC1AD2BC 
  ACF2FAD0 2E3D9D7B 05B7018A 3D02FF62 40B2BCCC AB936E2F 6E511E4C FABFA099 
  E82399C0 22F109B6 DE04016C 62843B67 862DAE88
        quit
crypto pki certificate chain SLA-TrustPoint
 certificate ca 01
  30820321 30820209 A0030201 02020101 300D0609 2A864886 F70D0101 0B050030 
  32310E30 0C060355 040A1305 43697363 6F312030 1E060355 04031317 43697363 
  6F204C69 63656E73 696E6720 526F6F74 20434130 1E170D31 33303533 30313934 
  3834375A 170D3338 30353330 31393438 34375A30 32310E30 0C060355 040A1305 
  43697363 6F312030 1E060355 04031317 43697363 6F204C69 63656E73 696E6720 
  526F6F74 20434130 82012230 0D06092A 864886F7 0D010101 05000382 010F0030 
  82010A02 82010100 A6BCBD96 131E05F7 145EA72C 2CD686E6 17222EA1 F1EFF64D 
  CBB4C798 212AA147 C655D8D7 9471380D 8711441E 1AAF071A 9CAE6388 8A38E520 
  1C394D78 462EF239 C659F715 B98C0A59 5BBB5CBD 0CFEBEA3 700A8BF7 D8F256EE 
  4AA4E80D DB6FD1C9 60B1FD18 FFC69C96 6FA68957 A2617DE7 104FDC5F EA2956AC 
  7390A3EB 2B5436AD C847A2C5 DAB553EB 69A9A535 58E9F3E3 C0BD23CF 58BD7188 
  68E69491 20F320E7 948E71D7 AE3BCC84 F10684C7 4BC8E00F 539BA42B 42C68BB7 
  C7479096 B4CB2D62 EA2F505D C7B062A4 6811D95B E8250FC4 5D5D5FB8 8F27D191 
  C55F0D76 61F9A4CD 3D992327 A8BB03BD 4E6D7069 7CBADF8B DF5F4368 95135E44 
  DFC7C6CF 04DD7FD1 02030100 01A34230 40300E06 03551D0F 0101FF04 04030201 
  06300F06 03551D13 0101FF04 05300301 01FF301D 0603551D 0E041604 1449DC85 
  4B3D31E5 1B3E6A17 606AF333 3D3B4C73 E8300D06 092A8648 86F70D01 010B0500 
  03820101 00507F24 D3932A66 86025D9F E838AE5C 6D4DF6B0 49631C78 240DA905 
  604EDCDE FF4FED2B 77FC460E CD636FDB DD44681E 3A5673AB 9093D3B1 6C9E3D8B 
  D98987BF E40CBD9E 1AECA0C2 2189BB5C 8FA85686 CD98B646 5575B146 8DFC66A8 
  467A3DF4 4D565700 6ADF0F0D CF835015 3C04FF7C 21E878AC 11BA9CD2 55A9232C 
  7CA7B7E6 C1AF74F6 152E99B7 B1FCF9BB E973DE7F 5BDDEB86 C71E3B49 1765308B 
  5FB0DA06 B92AFE7F 494E8A9E 07B85737 F3A58BE1 1A48A229 C37C1E69 39F08678 
  80DDCD16 D6BACECA EEBC7CF9 8428787B 35202CDC 60E4616A B623CDBD 230E3AFB 
  418616A9 4093E049 4D10AB75 27E86F73 932E35B5 8862FDAE 0275156F 719BB2F0 
  D697DF7F 28
        quit
!
license boot level ipservicesk9
!
!
diagnostic bootup level minimal
!
spanning-tree mode rapid-pvst
spanning-tree extend system-id
!
!
!         
redundancy
 mode sso
!
!
!
!
!
transceiver type all
 monitoring
!
!
class-map match-any system-cpp-police-topology-control
  description Topology control
class-map match-any system-cpp-police-sw-forward
  description Sw forwarding, L2 LVX data, LOGGING
class-map match-any system-cpp-default
  description Inter FED, EWLC control, EWLC data
class-map match-any system-cpp-police-sys-data
  description Learning cache ovfl, High Rate App, Exception, EGR Exception, NFL SAMPLED DATA, RPF Failed
class-map match-any system-cpp-police-punt-webauth
  description Punt Webauth
class-map match-any system-cpp-police-l2lvx-control
  description L2 LVX control packets
class-map match-any system-cpp-police-forus
  description Forus Address resolution and Forus traffic
class-map match-any system-cpp-police-multicast-end-station
  description MCAST END STATION
class-map match-any system-cpp-police-multicast
  description Transit Traffic and MCAST Data
class-map match-any system-cpp-police-l2-control
  description L2 control
class-map match-any system-cpp-police-dot1x-auth
  description DOT1X Auth
class-map match-any system-cpp-police-data
  description ICMP redirect, ICMP_GEN and BROADCAST
class-map match-any system-cpp-police-stackwise-virt-control
  description Stackwise Virtual
class-map match-any non-client-nrt-class
class-map match-any system-cpp-police-routing-control
  description Routing control and Low Latency
class-map match-any system-cpp-police-protocol-snooping
  description Protocol snooping
class-map match-any system-cpp-police-dhcp-snooping
  description DHCP snooping
class-map match-any system-cpp-police-system-critical
  description System Critical and Gold Pkt
!
policy-map system-cpp-policy
!
! 
!
!
!
!
!
!
!
!
!
interface Port-channel1
 no switchport
 ip address 10.0.2.2 255.255.255.0
!
interface Port-channel2
 no switchport
 ip address 10.1.1.2 255.255.255.0
!
interface GigabitEthernet0/0
 vrf forwarding Mgmt-vrf
 no ip address
 shutdown
 negotiation auto
!
interface GigabitEthernet1/0/1
 description Channel to D1
 no switchport
 no ip address
 channel-group 1 mode on
!
interface GigabitEthernet1/0/2
 description Channel to D1
 no switchport
 no ip address
 channel-group 1 mode on
!
interface GigabitEthernet1/0/3
 description Channel to D1
 no switchport
 no ip address
 channel-group 2 mode on
!         
interface GigabitEthernet1/0/4
 description Channel to D1
 no switchport
 no ip address
 channel-group 2 mode on
!
interface GigabitEthernet1/0/5
 shutdown
!
interface GigabitEthernet1/0/6
 shutdown
!
interface GigabitEthernet1/0/7
 shutdown
!
interface GigabitEthernet1/0/8
 shutdown
!
interface GigabitEthernet1/0/9
 shutdown
!
interface GigabitEthernet1/0/10
 shutdown 
!
interface GigabitEthernet1/0/11
 no switchport
 ip address 10.0.3.2 255.255.255.0
!
interface GigabitEthernet1/0/12
 shutdown
!
interface GigabitEthernet1/0/13
 shutdown
!
interface GigabitEthernet1/0/14
 shutdown
!
interface GigabitEthernet1/0/15
 shutdown
!
interface GigabitEthernet1/0/16
 shutdown
!
interface GigabitEthernet1/0/17
 shutdown
!         
interface GigabitEthernet1/0/18
 shutdown
!
interface GigabitEthernet1/0/19
 shutdown
!
interface GigabitEthernet1/0/20
 shutdown
!
interface GigabitEthernet1/0/21
 shutdown
!
interface GigabitEthernet1/0/22
 shutdown
!
interface GigabitEthernet1/0/23
 shutdown
!
interface GigabitEthernet1/0/24
 shutdown
!
interface GigabitEthernet1/1/1
!         
interface GigabitEthernet1/1/2
!
interface GigabitEthernet1/1/3
!
interface GigabitEthernet1/1/4
!
interface Vlan1
 no ip address
 shutdown
!
router ospf 1
 router-id 5.5.5.5
 network 10.0.2.0 0.0.0.255 area 0
 network 10.0.3.0 0.0.0.255 area 0
 network 10.1.1.0 0.0.0.255 area 1
!
ip forward-protocol nd
ip http server
ip http authentication local
ip http secure-server
!
!
!         
!
!
!
control-plane
 service-policy input system-cpp-policy
!
banner motd ^C This is D2, Trouble Ticket 8.1.2.3 ^C
alias exec reset.now tclsh flash:/enarsi/reset.tcl
!
line con 0
 exec-timeout 0 0
 logging synchronous
 stopbits 1
line aux 0
 stopbits 1
line vty 0 4
 login
line vty 5 15
 login
!
!
!
!         
!
!
!
end

Joseph W. Doherty · ‎03-14-2025

I haven't looked at the configs, but even before reading the prose, I saw a potential issue from the network diagram. After reading the prose, likely what I initially saw, is the root issue.

Hint: consider ABRs considerations, their purpose.

Andrew guory009 · ‎03-14-2025

@David Ruess

Thanks for your reply, which I think is very helpful. I searched and understood the key points you pointed out, and I realized that Area0 is the backbone network of OSPF1. R3 used to be used because of its connection with D2 in the backbone network, but now it is connected to R2 in Area2 as the subregion of the peer group. The network is unavailable because it is not directly connected to the backbone network.
I tried to use ospf virtual link to repair the fault, I linked R3 and R1, and Area2 was used as the transit area, but I found no obvious changes and the network fault was not removed, I did not find more solutions, and I was not clear about which keywords to search. I hope you can provide me with some help again.

Secondly, I also have some doubts about the graph below, for example, the key word Transmit Delay is 1 sec, State DOWN, DOWN is usually sensitive, is it the reason why the fault has not been removed

Joseph W. Doherty · ‎03-15-2025

"The network is unavailable because it is not directly connected to the backbone network."

BTW, it's not the network that's no longer has a connection to area 0 but it's area 3 that no longer has a connection to area 0. (This may seem a nick pick, but there's some nuances to this topology, which can easily confuse and are often misunderstood. However, I don't, yet, want to discuss those.)

"I tried to use ospf virtual link to repair the fault. . ."

An OSPF virtual link should be a solution (as also might be a GRE tunnel).

". . . I linked R3 and R1 . . . and the network fault was not removed . . ."

(Hint). Why did you choose that pair of routers?

Joseph W. Doherty · ‎03-15-2025

Oh, something else to consider, what if it was R1 that lost its connection to area zero rather than R3?

David Ruess · ‎03-14-2025

In addition to what @Joseph W. Doherty mentioned make sure you understand the Area numbers and what they mean. I.E. what Areas are allowed to talk to each other in the hierarchical structure that is OSPF!

-David

Giuseppe Larosa · ‎03-15-2025

Hello @Andrew guory009 ,

first of all, for configuration files it would be better to put them on text files as attachments.

As noted by other colleagues this lab has a design issue router R2 should not be connected to area 2 and area 3 at the same time unless it has a direct connection to the backbone area 0 or 0.0.0.0.0. R2 is not an ABR. My guess is that the purpose of this lab is to highlight this aspect.

The proposed fault isolates area 3 from the rest of the OSPF domain .

R2 can still ping because it has interfaces in area 3.

Virtual links are tricky and also you need to consider that the VL needs to connect the isolated area to the backbone going via a standard area. So the VL should be implemented between R1 and R2 not between R1 and R3.

Hope to help

Giuseppe

Joseph W. Doherty · ‎03-15-2025

Ah, you gave the answer ". . . the VL should be implemented between R1 and R2 not between R1 and R3."

BTW, although not yet seen as a problem, realize that wouldn't help lost of connectivity to area 2. (Of course, perhaps losing access to that area isn't important, but as you do have an alternative path, via R2, I would recommend using it to support both areas 2 and 3.)

Another approach would be to place the R1<>R2 and R2<>R3 links into area zero.

". . . this lab has a design issue router R2 should not be connected to area 2 and area 3 at the same time . . ."

Possibly shouldn't be is a bit strong, you may want something like it for an unusual purpose, but you need to understand how it works.

R2 has area topologies for both areas 2 and 3, and will route between them. However, unlike an ABR, it will not share either area 2's or 3's routes with other routers except those within the same area. So, R2 won't share area 3 routes with R1 nor share area 2 routes with R3.