My Network Lab: October 2018

Configuring an OSPF virtual link requires a minor amount of configuration just to get the link working, with several optional configuration items. Most of the optional configuration settings relate to features that would normally be configured on the interface connecting two neighboring routers, but with a virtual link, there is no such interface, so the parameters must be added to the area virtual-link command.

The following list summarizes the key configuration options on the area virtual-link router sub-command:

The remote-RID in the area <area-num> virtual-link <remote-RID> command refers to the other router’s RID.

The area-num in the area <area-num> virtual-link <remote-RID> command refers to the transit area over which the packets flow between the two routers.

The transit area over which the two routers communicate must not be a stubby area.

The optional configuration of OSPF neighbor authentication parameters, normally configured as interface sub-commands, must be configured as additional parameters on the area virtual-link command.

The optional configuration of Hello and Dead intervals, normally configured as interface sub-commands, must be configured as additional parameters on the area virtual-link command.

The router assigns the virtual link an OSPF cost as if it were a point-to-point link. The router calculates the cost as the cost to reach the router on the other end of the link, as calculated using the transit area’s LSDB.

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#interface loop 1

R1(config-if)#

*Jun 27 14:51:46.727: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback1, changed state to up

R1(config-if)#ip address 10.1.1.1 255.255.255.0

R1(config-if)#

R1(config-if)#interface loop 30

R1(config-if)#

*Jun 27 14:52:08.563: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback30, changed state to up

R1(config-if)#ip address 172.30.30.1 255.255.255.252

R1(config-if)#

R1(config-if)#interface serial 2/0

R1(config-if)#ip address 10.1.12.1 255.255.255.0

R1(config-if)#no shut

R1(config-if)#end

*Jun 27 14:52:42.415: %LINK-3-UPDOWN: Interface Serial2/0, changed state to up

*Jun 27 14:52:43.423: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/0, changed state to up

R1(config-if)#end

R1#

R2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R2(config)#interface loop 2

R2(config-if)#

*Jun 27 14:51:44.047: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback2, changed state to up

R2(config-if)#ip address 10.1.2.1 255.255.255.0

R2(config-if)#

R2(config-if)#interface serial 2/0

R2(config-if)#ip address 10.1.12.2 255.255.255.0

R2(config-if)#no shut

R2(config-if)#

*Jun 27 14:52:24.603: %LINK-3-UPDOWN: Interface Serial2/0, changed state to up

R2(config-if)#

*Jun 27 14:52:25.611: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/0, changed state to up

R2(config-if)#do ping 10.1.12.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.12.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 12/18/28 ms

R2(config-if)#

R2(config-if)#interface serial 2/1

R2(config-if)#ip address 10.1.23.2 255.255.255.0

R2(config-if)#no shut

R2(config-if)#

*Jun 27 14:52:50.275: %LINK-3-UPDOWN: Interface Serial2/1, changed state to up

R2(config-if)#

*Jun 27 14:52:51.283: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/1, changed state to up

R2(config-if)#end

R2#

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#interface loop 3

R3(config-if)#

*Jun 27 14:53:26.583: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback3, changed state to up

R3(config-if)#ip address 10.1.3.1 255.255.255.0

R3(config-if)#

R3(config-if)#interface loop 100

R3(config-if)#

*Jun 27 14:53:48.847: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback100, changed state to up

R3(config-if)#ip address 192.168.100.1 255.255.255.0

R3(config-if)#

R3(config-if)#interface loop 101

R3(config-if)#

*Jun 27 14:54:07.119: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback101, changed state to up

R3(config-if)#ip address 192.168.101.1 255.255.255.0

R3(config-if)#

R3(config-if)#interface loop 102

R3(config-if)#

*Jun 27 14:54:19.403: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback102, changed state to up

R3(config-if)#ip address 192.168.102.1 255.255.255.0

R3(config-if)#

R3(config-if)#interface loop 103

R3(config-if)#

*Jun 27 14:54:33.855: %LINEPROTO-5-UPDOWN: Line protocol on Interface Loopback103, changed state to up

R3(config-if)#ip address 192.168.103.1 255.255.255.0

R3(config-if)#

R3(config-if)#interface serial 2/1

R3(config-if)#ip address 10.1.23.3 255.255.255.0

R3(config-if)#no shut

R3(config-if)#

*Jun 27 14:54:55.175: %LINK-3-UPDOWN: Interface Serial2/1, changed state to up

R3(config-if)#

*Jun 27 14:54:56.183: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial2/1, changed state to up

R3(config-if)#do ping 10.1.23.2

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 10.1.23.2, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 20/23/28 ms

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#router ospf 1

R1(config-router)#router-id 1.1.1.1

R1(config-router)#network 10.1.12.0 0.0.0.255 area 0

R1(config-router)#network 10.1.1.0 0.0.0.255 area 0

R1(config-router)#interface loop 1

R1(config-if)#ip ospf network ?

broadcast Specify OSPF broadcast multi-access network

non-broadcast Specify OSPF NBMA network

point-to-multipoint Specify OSPF point-to-multipoint network

point-to-point Specify OSPF point-to-point network

R1(config-if)#ip ospf network point-to-point // DEFAULT LOOPBACK INTERFACE BEHAVIOR IN OSPF IS TO ADVERTISE A /32 HOST ROUTE; NEED TO ADVERTISE AS /24 IN OSPF

R1(config-if)#end

R1#

*Jun 27 15:08:39.371: %SYS-5-CONFIG_I: Configured from console by console

R1#

R1#show ip ospf // COMMAND TO VERIFY OSPF ROUTER ID; ISSUE A clear ip ospf <PROCESS ID> AFTER MAKING CHANGES

Routing Process "ospf 1" with ID 1.1.1.1

Start time: 00:23:21.372, Time elapsed: 00:00:48.992

Supports only single TOS(TOS0) routes

Supports opaque LSA

Supports Link-local Signaling (LLS)

Supports area transit capability

Supports NSSA (compatible with RFC 3101)

Event-log enabled, Maximum number of events: 1000, Mode: cyclic

Router is not originating router-LSAs with maximum metric

Initial SPF schedule delay 5000 msecs

Minimum hold time between two consecutive SPFs 10000 msecs

Maximum wait time between two consecutive SPFs 10000 msecs

Incremental-SPF disabled

Minimum LSA interval 5 secs

Minimum LSA arrival 1000 msecs

LSA group pacing timer 240 secs

Interface flood pacing timer 33 msecs

Retransmission pacing timer 66 msecs

Number of external LSA 0. Checksum Sum 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

Number of areas transit capable is 0

External flood list length 0

IETF NSF helper support enabled

Cisco NSF helper support enabled

Reference bandwidth unit is 100 mbps

Area BACKBONE(0) (Inactive)

Number of interfaces in this area is 2 (1 loopback)

Area has no authentication

SPF algorithm last executed 00:00:03.692 ago

SPF algorithm executed 3 times

Area ranges are

Number of LSA 1. Checksum Sum 0x00C8EB

Number of opaque link LSA 0. Checksum Sum 0x000000

Number of DCbitless LSA 0

Number of indication LSA 0

Number of DoNotAge LSA 0

Flood list length 0

R2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R2(config)#router ospf 1

R2(config-router)#router-id 2.2.2.2

R2(config-router)#network 10.1.12.0 0.0.0.255 area 0

R2(config-router)#

*Jun 27 15:08:51.767: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on Serial2/0 from LOADING to FULL, Loading Done

R2(config-router)#network 10.1.2.0 0.0.0.255 area 0

R2(config-router)#interface loop 2

R2(config-if)#ip ospf network point-to-point

R2(config-if)#end

R2#

*Jun 27 15:09:26.903: %SYS-5-CONFIG_I: Configured from console by console

R2#show ip ospf

Routing Process "ospf 1" with ID 2.2.2.2

Start time: 00:22:45.484, Time elapsed: 00:00:54.216

Supports only single TOS(TOS0) routes

Supports opaque LSA

Supports Link-local Signaling (LLS)

Supports area transit capability

Supports NSSA (compatible with RFC 3101)

Event-log enabled, Maximum number of events: 1000, Mode: cyclic

Router is not originating router-LSAs with maximum metric

Initial SPF schedule delay 5000 msecs

Minimum hold time between two consecutive SPFs 10000 msecs

Maximum wait time between two consecutive SPFs 10000 msecs

Incremental-SPF disabled

Minimum LSA interval 5 secs

Minimum LSA arrival 1000 msecs

LSA group pacing timer 240 secs

Interface flood pacing timer 33 msecs

Retransmission pacing timer 66 msecs

Number of external LSA 0. Checksum Sum 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

Number of areas transit capable is 0

External flood list length 0

IETF NSF helper support enabled

Cisco NSF helper support enabled

Reference bandwidth unit is 100 mbps

Area BACKBONE(0)

Number of interfaces in this area is 2 (1 loopback)

Area has no authentication

SPF algorithm last executed 00:00:05.212 ago

SPF algorithm executed 3 times

Area ranges are

Number of LSA 2. Checksum Sum 0x00E3A1

Number of opaque link LSA 0. Checksum Sum 0x000000

Number of DCbitless LSA 0

Number of indication LSA 0

Number of DoNotAge LSA 0

Flood list length 0

*Jun 27 15:10:41.635: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Serial2/0 from LOADING to FULL, Loading Done

R1#

R1#show ip ospf neighbor // VERIFY OSPF NEIGHBOR

Neighbor ID Pri State Dead Time Address Interface

2.2.2.2 0 FULL/ - 00:00:37 10.1.12.2 Serial2/0

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 5 subnets, 2 masks

C 10.1.1.0/24 is directly connected, Loopback1

L 10.1.1.1/32 is directly connected, Loopback1

O 10.1.2.0/24 [110/65] via 10.1.12.2, 00:00:54, Serial2/0

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.1/32 is directly connected, Serial2/0

172.30.0.0/16 is variably subnetted, 2 subnets, 2 masks

C 172.30.30.0/30 is directly connected, Loopback30

L 172.30.30.1/32 is directly connected, Loopback30

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

1.1.1.1 0 FULL/ - 00:00:31 10.1.12.1 Serial2/0

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks

O 10.1.1.0/24 [110/65] via 10.1.12.1, 00:02:08, Serial2/0

C 10.1.2.0/24 is directly connected, Loopback2

L 10.1.2.1/32 is directly connected, Loopback2

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.2/32 is directly connected, Serial2/0

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.2/32 is directly connected, Serial2/1

R2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R2(config)#router ospf 1

R2(config-router)#network 10.1.23.0 0.0.0.255 area 23

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#router ospf 1

R3(config-router)#router-id 3.3.3.3

R3(config-router)#network 10.1.23.0 0.0.0.255 area 23

R3(config-router)#

*Jun 27 15:12:31.823: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on Serial2/1 from LOADING to FULL, Loading Done

R3(config-router)#network 10.1.3.0 0.0.0.255 area 23

R3(config-router)#

R3(config-router)#interface loop 3

R3(config-if)#ip ospf network point-to-point

R3(config-if)#end

R3#

*Jun 27 15:13:05.111: %SYS-5-CONFIG_I: Configured from console by console

R3#show ip ospf

Routing Process "ospf 1" with ID 3.3.3.3

Start time: 00:26:02.648, Time elapsed: 00:00:49.976

Supports only single TOS(TOS0) routes

Supports opaque LSA

Supports Link-local Signaling (LLS)

Supports area transit capability

Supports NSSA (compatible with RFC 3101)

Event-log enabled, Maximum number of events: 1000, Mode: cyclic

Router is not originating router-LSAs with maximum metric

Initial SPF schedule delay 5000 msecs

Minimum hold time between two consecutive SPFs 10000 msecs

Maximum wait time between two consecutive SPFs 10000 msecs

Incremental-SPF disabled

Minimum LSA interval 5 secs

Minimum LSA arrival 1000 msecs

LSA group pacing timer 240 secs

Interface flood pacing timer 33 msecs

Retransmission pacing timer 66 msecs

Number of external LSA 0. Checksum Sum 0x000000

Number of opaque AS LSA 0. Checksum Sum 0x000000

Number of DCbitless external and opaque AS LSA 0

Number of DoNotAge external and opaque AS LSA 0

Number of areas in this router is 1. 1 normal 0 stub 0 nssa

Number of areas transit capable is 0

External flood list length 0

IETF NSF helper support enabled

Cisco NSF helper support enabled

Reference bandwidth unit is 100 mbps

Area 23

Number of interfaces in this area is 2 (1 loopback)

Area has no authentication

SPF algorithm last executed 00:00:07.688 ago

SPF algorithm executed 3 times

Area ranges are

Number of LSA 5. Checksum Sum 0x031D29

Number of opaque link LSA 0. Checksum Sum 0x000000

Number of DCbitless LSA 0

Number of indication LSA 0

Number of DoNotAge LSA 0

Flood list length 0

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

1.1.1.1 0 FULL/ - 00:00:38 10.1.12.1 Serial2/0

3.3.3.3 0 FULL/ - 00:00:34 10.1.23.3 Serial2/1

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#router ospf 1

R3(config-router)#network 192.168.100.0 0.0.3.255 area 100

R3(config-router)#interface loop 100

R3(config-if)#ip ospf network point-to-point

R3(config-if)#interface loop 101

R3(config-if)#ip ospf network point-to-point

R3(config-if)#interface loop 102

R3(config-if)#ip ospf network point-to-point

R3(config-if)#interface loop 103

R3(config-if)#ip ospf network point-to-point

R2#show ip route // CAN'T SEE ROUTES IN R3 AREA 100 SINCE IT'S NOT CONNECTED TO A BACKBONE AREA 0

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks

O 10.1.1.0/24 [110/65] via 10.1.12.1, 00:03:57, Serial2/0

C 10.1.2.0/24 is directly connected, Loopback2

L 10.1.2.1/32 is directly connected, Loopback2

O 10.1.3.0/24 [110/65] via 10.1.23.3, 00:02:51, Serial2/1

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.2/32 is directly connected, Serial2/0

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.2/32 is directly connected, Serial2/1

R2#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R2(config)#router ospf 1

R2(config-router)#area ?

<0-4294967295> OSPF area ID as a decimal value

A.B.C.D OSPF area ID in IP address format

R2(config-router)#area 23 ?

authentication Enable authentication

capability Enable area specific capability

default-cost Set the summary default-cost of a NSSA/stub area

filter-list Filter networks between OSPF areas

nssa Specify a NSSA area

range Summarize routes matching address/mask (border routers only)

sham-link Define a sham link and its parameters

stub Specify a stub area

virtual-link Define a virtual link and its parameters

R2(config-router)#area 23 virtual-link ?

A.B.C.D ID (IP addr) associated with virtual link neighbor

R2(config-router)#area 23 virtual-link 3.3.3.3 // OSPF VIRTUAL LINK IS A WORK AROUND SOLUTION TO CONNECT A DISCONTIGUOUS AREA TO BACKBONE AREA 0

*Jun 27 15:17:36.575: %OSPF-5-ADJCHG: Process 1, Nbr 3.3.3.3 on OSPF_VL0 from LOADING to FULL, Loading Done

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#router ospf 1

R3(config-router)#area 23 virtual-link 2.2.2.2

R3(config-router)#

*Jun 27 15:17:46.371: %OSPF-5-ADJCHG: Process 1, Nbr 2.2.2.2 on OSPF_VL0 from LOADING to FULL, Loading Done

R2#show ip route // CAN NOW SEE ROUTES IN R3 AREA 100

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks

O 10.1.1.0/24 [110/65] via 10.1.12.1, 00:06:27, Serial2/0

C 10.1.2.0/24 is directly connected, Loopback2

L 10.1.2.1/32 is directly connected, Loopback2

O 10.1.3.0/24 [110/65] via 10.1.23.3, 00:05:21, Serial2/1

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.2/32 is directly connected, Serial2/0

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.2/32 is directly connected, Serial2/1

O IA 192.168.100.0/24 [110/65] via 10.1.23.3, 00:00:31, Serial2/1

O IA 192.168.101.0/24 [110/65] via 10.1.23.3, 00:00:31, Serial2/1

O IA 192.168.102.0/24 [110/65] via 10.1.23.3, 00:00:31, Serial2/1

O IA 192.168.103.0/24 [110/65] via 10.1.23.3, 00:00:31, Serial2/1

R2#show ip ospf neighbor

Neighbor ID Pri State Dead Time Address Interface

3.3.3.3 0 FULL/ - - 10.1.23.3 OSPF_VL0

1.1.1.1 0 FULL/ - 00:00:32 10.1.12.1 Serial2/0

3.3.3.3 0 FULL/ - 00:00:39 10.1.23.3 Serial2/1

R2#show ip ospf interface

OSPF_VL0 is up, line protocol is up

Internet Address 10.1.23.2/24, Area 0, Attached via Not Attached

Process ID 1, Router ID 2.2.2.2, Network Type VIRTUAL_LINK, Cost: 64

Topology-MTID Cost Disabled Shutdown Topology Name

0 64 no no Base

Configured as demand circuit

Run as demand circuit

DoNotAge LSA allowed

Transmit Delay is 1 sec, State POINT_TO_POINT

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

oob-resync timeout 40

Hello due in 00:00:06

Supports Link-local Signaling (LLS)

Cisco NSF helper support enabled

IETF NSF helper support enabled

Index 3/4, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 1, maximum is 1

Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 3.3.3.3 (Hello suppressed)

Suppress hello for 1 neighbor(s)

Loopback2 is up, line protocol is up

Internet Address 10.1.2.1/24, Area 0, Attached via Network Statement

Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 1

Topology-MTID Cost Disabled Shutdown Topology Name

0 1 no no Base

Transmit Delay is 1 sec, State POINT_TO_POINT

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

oob-resync timeout 40

Supports Link-local Signaling (LLS)

Cisco NSF helper support enabled

IETF NSF helper support enabled

Index 2/2, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 0, maximum is 0

Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 0, Adjacent neighbor count is 0

Suppress hello for 0 neighbor(s)

Serial2/0 is up, line protocol is up

Internet Address 10.1.12.2/24, Area 0, Attached via Network Statement

Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 64

Topology-MTID Cost Disabled Shutdown Topology Name

0 64 no no Base

Transmit Delay is 1 sec, State POINT_TO_POINT

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

oob-resync timeout 40

Hello due in 00:00:06

Supports Link-local Signaling (LLS)

Cisco NSF helper support enabled

IETF NSF helper support enabled

Index 1/1, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 1, maximum is 6

Last flood scan time is 0 msec, maximum is 4 msec

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 1.1.1.1

Suppress hello for 0 neighbor(s)

Serial2/1 is up, line protocol is up

Internet Address 10.1.23.2/24, Area 23, Attached via Network Statement

Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 64

Topology-MTID Cost Disabled Shutdown Topology Name

0 64 no no Base

Transmit Delay is 1 sec, State POINT_TO_POINT

Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

oob-resync timeout 40

Hello due in 00:00:07

Supports Link-local Signaling (LLS)

Cisco NSF helper support enabled

IETF NSF helper support enabled

Index 1/3, flood queue length 0

Next 0x0(0)/0x0(0)

Last flood scan length is 1, maximum is 1

Last flood scan time is 0 msec, maximum is 0 msec

Neighbor Count is 1, Adjacent neighbor count is 1

Adjacent with neighbor 3.3.3.3

Suppress hello for 0 neighbor(s)

R3#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R3(config)#router ospf 1

R3(config-router)#area 100 ?

authentication Enable authentication

capability Enable area specific capability

default-cost Set the summary default-cost of a NSSA/stub area

filter-list Filter networks between OSPF areas

nssa Specify a NSSA area

range Summarize routes matching address/mask (border routers only)

sham-link Define a sham link and its parameters

stub Specify a stub area

virtual-link Define a virtual link and its parameters

R3(config-router)#area 100 range ?

A.B.C.D IP address to match

R3(config-router)#area 100 range 192.168.100.0 255.255.252.0 // SUMMARIZE A SUPERNET ROUTE IN OSPF

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks

O 10.1.1.0/24 [110/65] via 10.1.12.1, 00:09:13, Serial2/0

C 10.1.2.0/24 is directly connected, Loopback2

L 10.1.2.1/32 is directly connected, Loopback2

O 10.1.3.0/24 [110/65] via 10.1.23.3, 00:08:07, Serial2/1

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.2/32 is directly connected, Serial2/0

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.2/32 is directly connected, Serial2/1

O IA 192.168.100.0/22 [110/65] via 10.1.23.3, 00:00:16, Serial2/1

R2#show ip ospf database

OSPF Router with ID (2.2.2.2) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link count

1.1.1.1 1.1.1.1 754 0x80000004 0x00AE96 3

2.2.2.2 2.2.2.2 229 0x80000005 0x00B10A 4

3.3.3.3 3.3.3.3 1 (DNA) 0x80000002 0x00ADFC 1

Summary Net Link States (Area 0)

Link ID ADV Router Age Seq# Checksum

10.1.3.0 2.2.2.2 514 0x80000001 0x002ABB

10.1.3.0 3.3.3.3 6 (DNA) 0x80000001 0x008998

10.1.23.0 2.2.2.2 570 0x80000001 0x00438F

10.1.23.0 3.3.3.3 6 (DNA) 0x80000001 0x0025A9

192.168.100.0 3.3.3.3 1 (DNA) 0x80000002 0x00263E

Router Link States (Area 23)

Link ID ADV Router Age Seq# Checksum Link count

2.2.2.2 2.2.2.2 228 0x80000003 0x0099A1 2

3.3.3.3 3.3.3.3 229 0x80000005 0x00E92B 3

Summary Net Link States (Area 23)

Link ID ADV Router Age Seq# Checksum

10.1.1.0 2.2.2.2 580 0x80000001 0x0040A7

10.1.2.0 2.2.2.2 580 0x80000001 0x00B274

10.1.12.0 2.2.2.2 580 0x80000001 0x00BC21

192.168.100.0 3.3.3.3 49 0x80000002 0x00263E

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

+ - replicated route, % - next hop override

Gateway of last resort is not set

10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks

O 10.1.1.0/24 [110/129] via 10.1.23.2, 00:01:45, Serial2/1

O 10.1.2.0/24 [110/65] via 10.1.23.2, 00:01:45, Serial2/1

C 10.1.3.0/24 is directly connected, Loopback3

L 10.1.3.1/32 is directly connected, Loopback3

O 10.1.12.0/24 [110/128] via 10.1.23.2, 00:01:45, Serial2/1

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.3/32 is directly connected, Serial2/1

O 192.168.100.0/22 is a summary, 00:01:45, Null0 // AN OSPF SUMMARY ROUTE CREATED A NULL0 OR ROUTE TO A BIT BUCKET WHICH DROPS TRAFFIC NOT COVERED BY THE SUMMARY ROUTE

192.168.100.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.100.0/24 is directly connected, Loopback100

L 192.168.100.1/32 is directly connected, Loopback100

192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.101.0/24 is directly connected, Loopback101

L 192.168.101.1/32 is directly connected, Loopback101

192.168.102.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.102.0/24 is directly connected, Loopback102

L 192.168.102.1/32 is directly connected, Loopback102

192.168.103.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.103.0/24 is directly connected, Loopback103

L 192.168.103.1/32 is directly connected, Loopback103

R1#conf t

Enter configuration commands, one per line. End with CNTL/Z.

R1(config)#router ospf 1

R1(config-router)#?

Router configuration commands:

address-family Enter Address Family command mode

area OSPF area parameters

auto-cost Calculate OSPF interface cost according to bandwidth

bfd BFD configuration commands

capability Enable specific OSPF feature

compatible OSPF compatibility list

default Set a command to its defaults

default-information Control distribution of default information

default-metric Set metric of redistributed routes

discard-route Enable or disable discard-route installation

distance Define an administrative distance

distribute-list Filter networks in routing updates

domain-id OSPF domain-id

domain-tag OSPF domain-tag

event-log OSPF Event Logging

exit Exit from routing protocol configuration mode

help Description of the interactive help system

ignore Do not complain about specific event

interface-id Source of the interface ID

ispf Enable incremental SPF computation

limit Limit a specific OSPF feature

local-rib-criteria Enable or disable usage of local RIB as route criteria

log-adjacency-changes Log changes in adjacency state

max-lsa maximum number of LSAs OSPF process will receive

max-metric Set maximum metric

maximum-paths Forward packets over multiple paths

mpls Configure MPLS routing protocol parameters

neighbor Specify a neighbor router

network Enable routing on an IP network

no Negate a command or set its defaults

nsf Non-stop forwarding

passive-interface Suppress routing updates on an interface

prefix-suppression OSPF prefix suppression

priority OSPF topology priority

queue-depth OSPF Hello/Router process queue depth

redistribute Redistribute information from another routing protocol

router-id router-id for this OSPF process

shutdown Shutdown the OSPF protocol under the current instance

snmp Modify snmp parameters

summary-address Configure IP address summaries

timers Adjust routing timers

traffic-share How to compute traffic share over alternate paths

ttl-security TTL security check

R1(config-router)#default-information ?

originate Distribute a default route

R1(config-router)#default-information originate ?

always Always advertise default route

metric OSPF default metric

metric-type OSPF metric type for default routes

route-map Route-map reference

<cr>

R1(config-router)#default-information originate always // GENERATES AND ADVERTISE A DEFAULT ROUTE IN OSPF; THE always KEYWORD WILL GENERATE A DEFAULT ROUTE EVEN IF NONE EXIST IN THE ROUTING TABLE

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

+ - replicated route, % - next hop override

Gateway of last resort is 10.1.12.1 to network 0.0.0.0

O*E2 0.0.0.0/0 [110/1] via 10.1.12.1, 00:00:17, Serial2/0

10.0.0.0/8 is variably subnetted, 8 subnets, 2 masks

O 10.1.1.0/24 [110/65] via 10.1.12.1, 00:12:21, Serial2/0

C 10.1.2.0/24 is directly connected, Loopback2

L 10.1.2.1/32 is directly connected, Loopback2

O 10.1.3.0/24 [110/65] via 10.1.23.3, 00:11:15, Serial2/1

C 10.1.12.0/24 is directly connected, Serial2/0

L 10.1.12.2/32 is directly connected, Serial2/0

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.2/32 is directly connected, Serial2/1

O IA 192.168.100.0/22 [110/65] via 10.1.23.3, 00:03:24, Serial2/1

R2#ping 172.30.30.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.30.30.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/17/20 ms

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

+ - replicated route, % - next hop override

Gateway of last resort is 10.1.23.2 to network 0.0.0.0

O*E2 0.0.0.0/0 [110/1] via 10.1.23.2, 00:00:38, Serial2/1

10.0.0.0/8 is variably subnetted, 7 subnets, 2 masks

O 10.1.1.0/24 [110/129] via 10.1.23.2, 00:03:50, Serial2/1

O 10.1.2.0/24 [110/65] via 10.1.23.2, 00:03:50, Serial2/1

C 10.1.3.0/24 is directly connected, Loopback3

L 10.1.3.1/32 is directly connected, Loopback3

O 10.1.12.0/24 [110/128] via 10.1.23.2, 00:03:50, Serial2/1

C 10.1.23.0/24 is directly connected, Serial2/1

L 10.1.23.3/32 is directly connected, Serial2/1

O 192.168.100.0/22 is a summary, 00:03:50, Null0

192.168.100.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.100.0/24 is directly connected, Loopback100

L 192.168.100.1/32 is directly connected, Loopback100

192.168.101.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.101.0/24 is directly connected, Loopback101

L 192.168.101.1/32 is directly connected, Loopback101

192.168.102.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.102.0/24 is directly connected, Loopback102

L 192.168.102.1/32 is directly connected, Loopback102

192.168.103.0/24 is variably subnetted, 2 subnets, 2 masks

C 192.168.103.0/24 is directly connected, Loopback103

L 192.168.103.1/32 is directly connected, Loopback103

R3#ping 172.30.30.1

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to 172.30.30.1, timeout is 2 seconds:

!!!!!

Success rate is 100 percent (5/5), round-trip min/avg/max = 16/40/68 ms

My Network Lab

Friday, October 26, 2018

Configuring OSPF Virtual Links