OSPF · Azriel Fidzlie

Chapters on Cisco - Artikel ini merupakan bagian dari sebuah seri.

Bagian 6: Artikel ini

Bagian 7: BGP

OSPF
#

(Open Shortest Path First)
#

Open Standard.
Link-State routing protocol.
Using SPF/Dijkstra Algorithm.
Multicast for exchange information use port 89.
Administrative distance 110.
Classless routing protocol support VLSM/CIDR.
Support IPv6.
Metric using cost.
Fast convergence.
Equal load balancing only.
Using areas (backbone area and non-backbone areas).

Link-state mengetahui peta keseluruhan (topology) dalam jaringan untuk menentukan shortest path.

Link = interface dari router.

State = ke router neighbor mana interface tadi terhubung.

Link state router bekerja dengan mengirim link-state advertisement (LSA) ke router link-state lain dan disimpan di link-state database (LSDB). LSA seperti puzzle yang membentuk LSDB. LSDB adalah gambaran keseluruhan jaringan yang kita sebut topology. Ketika LSDB sudah lengkap, maka OSPF akan menghitung shortest path.

OSPF bekerja dengan konsep area. Area yang harus ada pada OSPF adalah area 0 atau backbone area. Area-area lain (non-backbone area) yang ingin terhubung, harus melalui backbone area.

Pembagian area ini bertujuan untuk memanajemen traffic dan mengurangi resources yang dipakai oleh router. Ada beberapa jenis router dalam OSPF.

Backbone router = router dalam backbone area.

Area Border Router (ABR) = router dalam 2 area.

Autonomous System Border Router (ASBR) = router yang terhubung ke network lain yang menjalankan routing yang berbeda.

OSPF menggunakan metric yang disebut cost. Cost dihitung berdasarkan bandwidth suatu interface.

Cost = reference bandwidth / interface bandwidth

Default reference bandwidth adalah 100Mbit, tapi ini bisa diubah karena saat ini sudah ada interface yang sampai giga.

Setiap LSA mempunyai aging timer yaitu batas waktu berlaku. Defaultnya LSA valid selama 30 menit. Setelah itu akan expire dan dikirim lagi LSA baru dengan sequence number yang lebih tinggi.

OSPF Basic Configuration
#

Ketikkan konfigurasi interface berikut.

R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
!
router ospf 13
 router-id 1.1.1.1
 network 1.1.1.1 0.0.0.0 area 0
 network 12.12.12.0 0.0.0.255 area 0
!

R2
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
!
interface Serial1/0
 ip address 23.23.23.2 255.255.255.0
!
router ospf 13
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 10
 network 12.12.12.0 0.0.0.255 area 0
 network 23.23.23.0 0.0.0.255 area 10
!

R3
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 23.23.23.3 255.255.255.0
!
router ospf 14
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 10
 network 23.23.23.0 0.0.0.255 area 10
!

Cek tabel routing.

R1#sh ip route

Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:07:41, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:07:41, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:07:41, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#

R2#sh ip route

Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/11] via 12.12.12.1, 00:08:04, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:08:39, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2#

R3#sh ip route

Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/75] via 23.23.23.2, 00:08:17, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:08:52, Serial1/0
    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O IA    12.12.12.0 [110/74] via 23.23.23.2, 00:08:52, Serial1/0
R3#

Tes ping.

R1#ping 2.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 8/75/144 ms

R1#ping 3.3.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 12/128/288 ms
R1#

R2#sh ip ospf database
            OSPF Router with ID (2.2.2.2) (Process ID 13)

            Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         616         0x80000002  0x0015AB 2
2.2.2.2         2.2.2.2         615         0x80000002  0x00F9D1 1

            Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.2      2.2.2.2         615         0x80000001  0x0014EB

            Summary Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum
2.2.2.2         2.2.2.2         656         0x80000001  0x00FA31
3.3.3.3         2.2.2.2         646         0x80000001  0x004F98
23.23.23.0      2.2.2.2         656         0x80000001  0x00901F

            Router Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum Link count
2.2.2.2         2.2.2.2         655         0x80000002  0x009C44 3
3.3.3.3         3.3.3.3         658         0x80000002  0x00BB1D 3

            Summary Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
1.1.1.1         2.2.2.2         613         0x80000001  0x008D98
12.12.12.0      2.2.2.2         658         0x80000001  0x00FF07
R2#

OSPF Virtual Link
#

R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
!
router ospf 13
 router-id 1.1.1.1
 network 1.1.1.1 0.0.0.0 area 0
 network 12.12.12.0 0.0.0.255 area 1
!

R2
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
!
interface Serial1/0
 ip address 23.23.23.2 255.255.255.0
!
router ospf 13
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 1
 network 12.12.12.0 0.0.0.255 area 1
 network 23.23.23.0 0.0.0.255 area 2
!

R3
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 23.23.23.3 255.255.255.0
!
router ospf 14
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 2
 network 23.23.23.0 0.0.0.255 area 2
!

Cek tabel routing.

R1(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:00:21, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1(config-router)#

R2(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/11] via 12.12.12.1, 00:01:33, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:01:43, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2(config-router)#

R3(config-router)#do sh ip route
Gateway of last resort is not set

    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
R3(config-router)#

Cek database OSPF.

R1#sh ip ospf database

            OSPF Router with ID (1.1.1.1) (Process ID 13)

            Router Link States (Area 0)
Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         261         0x80000001  0x00D351 1

            Summary Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum
2.2.2.2         1.1.1.1         189         0x80000001  0x007DA8
12.12.12.0      1.1.1.1         257         0x80000001  0x001EEC

            Router Link States (Area 1)

Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         193         0x80000002  0x00389C 1
2.2.2.2         2.2.2.2         195         0x80000002  0x00298A 2

            Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.2      2.2.2.2         195         0x80000001  0x0014EB

            Summary Net Link States (Area 1)

Link ID         ADV Router      Age         Seq#        Checksum
1.1.1.1         1.1.1.1         297         0x80000001  0x0047EC
R1#

R3#sh ip ospf database

            OSPF Router with ID (3.3.3.3) (Process ID 14)

            Router Link States (Area 2)

Link ID         ADV Router      Age         Seq#                Checksum Link count
2.2.2.2         2.2.2.2         293         0x80000002          0x00D624 2
3.3.3.3         3.3.3.3         287         0x80000002          0x00BB1D 3
R3#

Konfigurasi virtual link: area area-id virtual-link router-id

R1(config)#router ospf 13
R1(config-router)#area 1 virtual-link ?
    A.B.C.D ID (IP addr) associated with virtual link neighbor

R1(config-router)#area 1 virtual-link 2.2.2.2

R2(config-router)#area 1 virtual-link 1.1.1.1
*Mar 1 00:09:45.563: %OSPF-5-ADJCHG: Process 13, Nbr 1.1.1.1 on OSPF_VL0
from LOADING to FULL, Loading Done

R1#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:08:38, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:00:48, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:00:48, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#

Network 3.3.3.3 belum ada pada tabel routing.

R2(config-router)#area 2 virtual-link 3.3.3.3

R3(config-router)#area 2 virtual-link 2.2.2.2
*Mar 1 00:12:26.355: %OSPF-5-ADJCHG: Process 14, Nbr 2.2.2.2 on OSPF_VL0
from LOADING to FULL, Loading Done

Cek lagi

R1#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:12:02, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:01:34, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:04:11, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#ping 2.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 56/100/204 ms
R1#ping 3.3.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/148/204 ms
R1#

Cek virtual link.

R1#sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 2.2.2.2 is up
    Run as demand circuit
    DoNotAge LSA allowed.
    Transit area 1, via interface FastEthernet0/0, Cost of using 10
    Transmit Delay is 1 sec, State POINT_TO_POINT,
    Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
        Hello due in 00:00:09
        Adjacency State FULL (Hello suppressed)
        Index 1/2, retransmission queue length 0, number of retransmission 0
        First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
        Last retransmission scan length is 0, maximum is 0
        Last retransmission scan time is 0 msec, maximum is 0 msec
R1#

2#sh ip ospf virtual-links
Virtual Link OSPF_VL1 to router 3.3.3.3 is up
    Run as demand circuit
    DoNotAge LSA allowed.
    Transit area 2, via interface Serial1/0, Cost of using 64
    Transmit Delay is 1 sec, State POINT_TO_POINT,
    Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
        Hello due in 00:00:07
        Adjacency State FULL (Hello suppressed)
        Index 2/4, retransmission queue length 0, number of retransmission 0
        First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
        Last retransmission scan length is 0, maximum is 0
        Last retransmission scan time is 0 msec, maximum is 0 msec
Virtual Link OSPF_VL0 to router 1.1.1.1 is up
    Run as demand circuit
    DoNotAge LSA allowed.
    Transit area 1, via interface FastEthernet0/0, Cost of using 10
    Transmit Delay is 1 sec, State POINT_TO_POINT,
    Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
        Hello due in 00:00:02
        Adjacency State FULL (Hello suppressed)
        Index 1/3, retransmission queue length 0, number of retransmission 1
        First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
        Last retransmission scan length is 1, maximum is 1
        Last retransmission scan time is 0 msec, maximum is 0 msec
R2#

R3#sh ip ospf virtual-links
Virtual Link OSPF_VL0 to router 2.2.2.2 is up
    Run as demand circuit
    DoNotAge LSA allowed.
    Transit area 2, via interface Serial1/0, Cost of using 64
    Transmit Delay is 1 sec, State POINT_TO_POINT,
    Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
        Hello due in 00:00:01
        Adjacency State FULL (Hello suppressed)
        Index 1/2, retransmission queue length 0, number of retransmission 0
        First 0x0(0)/0x0(0) Next 0x0(0)/0x0(0)
        Last retransmission scan length is 0, maximum is 0
        Last retransmission scan time is 0 msec, maximum is 0 msec
R3#

OSPF GRE Tunnel
#

Hapus virtual link terlebih dahulu.

R1(config)#router ospf 13
R1(config-router)#no area 1 virtual-link 2.2.2.2

R2(config)#router ospf 13
R2(config-router)#no area 1 virtual-link 1.1.1.1
R2(config-router)#no area 2 virtual-link 3.3.3.3

R3(config)#router ospf 14
R3(config-router)#no area 2 virtual-link 2.2.2.2

Konfigurasi GRE tunnel.

R1(config)#int tun1
R1(config-if)#ip add 102.102.102.1 255.255.255.0
R1(config-if)#tunnel source 12.12.12.1
R1(config-if)#tunnel destination 12.12.12.2
R1(config-if)#router ospf 13
R1(config-router)#net 102.102.102.1 0.0.0.0 area 0

R2(config)#int tun1
R2(config-if)#ip add 102.102.102.2 255.255.255.0
R2(config-if)#tunnel destination 12.12.12.1
R2(config-if)#tunnel source 12.12.12.2
R2(config-if)#router ospf 13
R2(config-router)#net 102.102.102.2 0.0.0.0 area 0

R1#sh ip route
Gateway of last resort is not set

    102.0.0.0/24 is subnetted, 1 subnets
C       102.102.102.0 is directly connected, Tunnel1
    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:11:26, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/11176] via 102.102.102.2, 00:03:52, Tunnel1
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/11175] via 102.102.102.2, 00:03:52, Tunnel1
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#ping 2.2.2.2

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 2.2.2.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 32/96/284 ms
R1#ping 3.3.3.3

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 3.3.3.3, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 92/200/312 ms
R1#

R1#sh ip int br
Interface               IP-Address      OK? Method  Status
Protocol
FastEthernet0/0         12.12.12.1      YES NVRAM   up
up
FastEthernet0/1         unassigned      YES NVRAM   administratively down
down
Serial1/0               unassigned      YES NVRAM   administratively down
down
Serial1/1               unassigned      YES NVRAM   administratively down
down
Serial1/2               unassigned      YES NVRAM   administratively down
down
Serial1/3               unassigned      YES NVRAM   administratively down
down
Loopback0               1.1.1.1         YES NVRAM   up
up
Tunnel1                 102.102.102.1   YES manual  up
up
R1#

OSPF Standar Area
#

R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
!
router ospf 13
 router-id 1.1.1.1
 network 1.1.1.1 0.0.0.0 area 10
 network 12.12.12.0 0.0.0.255 area 10
!

R2
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
!
interface Serial1/0
 ip address 23.23.23.2 255.255.255.0
!
router ospf 13
 router-id 2.2.2.2
 network 2.2.2.2 0.0.0.0 area 0
 network 12.12.12.0 0.0.0.255 area 10
 network 23.23.23.0 0.0.0.255 area 0
!

R3
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 23.23.23.3 255.255.255.0
!
router ospf 14
 router-id 3.3.3.3
 network 3.3.3.3 0.0.0.0 area 0
 network 23.23.23.0 0.0.0.255 area 0
!

Buat interface loopback di R3 dan masukkan beberapa interfacenya ke EIGRP.

interface Loopback1
 ip address 33.33.33.1 255.255.255.255
!
interface Loopback2
 ip address 33.33.33.2 255.255.255.255
!
interface Loopback3
 ip address 33.33.33.3 255.255.255.255
!
interface Loopback4
 ip address 33.33.33.4 255.255.255.255
!
interface Loopback5
 ip address 33.33.33.5 255.255.255.255
!
interface Loopback6
 ip address 33.33.33.6 255.255.255.255
!
interface Loopback7
 ip address 33.33.33.7 255.255.255.255
!
interface Loopback8
 ip address 33.33.33.8 255.255.255.255
!

router eigrp 2
net 33.33.33.1 0.0.0.0
net 33.33.33.2 0.0.0.0
net 33.33.33.3 0.0.0.0
net 33.33.33.4 0.0.0.0
no auto-summary

Masukkan interface yang lain ke OSPF dengan area 100 dan redistribute EIGRP ke OSPF lalu cek tabel routing R1.

router ospf 14
net 33.33.33.5 0.0.0.0 area 100
net 33.33.33.6 0.0.0.0 area 100
net 33.33.33.7 0.0.0.0 area 100
net 33.33.33.8 0.0.0.0 area 100
redistribute eigrp 2 subnets

Cek R1.
R1(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:00:28, FastEthernet0/0
    33.0.0.0/32 is subnetted, 8 subnets
O E2    33.33.33.1 [110/20] via 12.12.12.2, 00:00:03, FastEthernet0/0
O E2    33.33.33.3 [110/20] via 12.12.12.2, 00:00:03, FastEthernet0/0
O E2    33.33.33.2 [110/20] via 12.12.12.2, 00:00:03, FastEthernet0/0
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:00:08, FastEthernet0/0
O E2    33.33.33.4 [110/20] via 12.12.12.2, 00:00:04, FastEthernet0/0
O IA    33.33.33.7 [110/75] via 12.12.12.2, 00:00:09, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:00:09, FastEthernet0/0
O IA    33.33.33.8 [110/75] via 12.12.12.2, 00:00:09, FastEthernet0/0
        3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:00:11, FastEthernet0/0
        23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:00:31, FastEthernet0/0
        12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1(config-router)#

R1(config-router)#do sh ip ospf database

            OSPF Router with ID (1.1.1.1) (Process ID 13)

            Router Link States (Area 10)
Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         127         0x80000002  0x0015AB 2
2.2.2.2         2.2.2.2         127         0x80000002  0x00F9D1 1

            Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.2      2.2.2.2         127         0x80000001  0x0014EB

            Summary Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
2.2.2.2         2.2.2.2         193         0x80000001  0x00FA31
3.3.3.3         2.2.2.2         103         0x80000001  0x004F98
23.23.23.0      2.2.2.2         193         0x80000001  0x00901F
33.33.33.5      2.2.2.2         103         0x80000001  0x00FE8C
33.33.33.6      2.2.2.2         103         0x80000001  0x00F495
33.33.33.7      2.2.2.2         103         0x80000001  0x00EA9E
33.33.33.8      2.2.2.2         103         0x80000001  0x00E0A7

            Summary ASB Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
3.3.3.3         2.2.2.2         105         0x80000001  0x0037B0

            Type-5 AS External Link States

Link ID         ADV Router      Age         Seq#        Checksum Tag
33.33.33.1      3.3.3.3         433         0x80000001  0x00DA55 0
33.33.33.2      3.3.3.3         433         0x80000001  0x00D05E 0
33.33.33.3      3.3.3.3         433         0x80000001  0x00C667 0
33.33.33.4      3.3.3.3         433         0x80000001  0x00BC70 0
R1(config-router)#

OSPF Stub Area
#

Cek tabel routing R1.

R1#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:00:04, FastEthernet0/0
    33.0.0.0/32 is subnetted, 8 subnets
O E2    33.33.33.1 [110/20] via 12.12.12.2, 00:00:04, FastEthernet0/0
O E2    33.33.33.3 [110/20] via 12.12.12.2, 00:00:04, FastEthernet0/0
O E2    33.33.33.2 [110/20] via 12.12.12.2, 00:00:04, FastEthernet0/0
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:00:04, FastEthernet0/0
O E2    33.33.33.4 [110/20] via 12.12.12.2, 00:00:05, FastEthernet0/0
O IA    33.33.33.7 [110/75] via 12.12.12.2, 00:00:05, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:00:05, FastEthernet0/0
O IA    33.33.33.8 [110/75] via 12.12.12.2, 00:00:05, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:00:07, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:00:07, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0

Konfigurasi stub.

R1(config-router)#area 10 stub
R2(config-router)#area 10 stub

Sekarang cek tabel routing lagi.

R1(config-router)#do sh ip route
Gateway of last resort is 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:02:06, FastEthernet0/0
     33.0.0.0/32 is subnetted, 4 subnets
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:02:06, FastEthernet0/0
O IA    33.33.33.7 [110/75] via 12.12.12.2, 00:02:06, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:02:06, FastEthernet0/0
O IA    33.33.33.8 [110/75] via 12.12.12.2, 00:02:07, FastEthernet0/0
        3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:02:07, FastEthernet0/0
     23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:02:08, FastEthernet0/0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*IA 0.0.0.0/0 [110/11] via 12.12.12.2, 00:02:09, FastEthernet0/0

E2 hilang diganti dengan 0*. Cek database OSPF.

R1#sh ip ospf database

            OSPF Router with ID (1.1.1.1) (Process ID 13)

            Router Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         339         0x80000005  0x00687D 2
2.2.2.2         2.2.2.2         499         0x80000005  0x0012B8 1

            Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.2      2.2.2.2         495         0x80000003  0x002ED1

            Summary Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
0.0.0.0         2.2.2.2         501         0x80000001  0x0075C0
2.2.2.2         2.2.2.2         501         0x80000002  0x001716
3.3.3.3         2.2.2.2         501         0x80000002  0x006B7D
23.23.23.0      2.2.2.2         501         0x80000002  0x00AC04
33.33.33.5      2.2.2.2         501         0x80000002  0x001B71
33.33.33.6      2.2.2.2         501         0x80000002  0x00117A
33.33.33.7      2.2.2.2         501         0x80000002  0x000783
33.33.33.8      2.2.2.2         503         0x80000002  0x00FC8C

OSPF Totally Stub Area
#

Konfigurasi totally stub.

R2(config-router)#no area 10 stub
R2(config-router)#area 10 stub no-summary

Cek tabel routing dan OSPF database.

R1#sh ip route
Gateway of last resort is 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*IA 0.0.0.0/0 [110/11] via 12.12.12.2, 00:00:47, FastEthernet0/0

R1#sh ip ospf database

            OSPF Router with ID (1.1.1.1) (Process ID 13)

            Router Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         251         0x80000004  0x002F91 2
2.2.2.2         2.2.2.2         257         0x80000004  0x0014B7 1

            Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.2      2.2.2.2         252         0x80000003  0x002ED1

            Summary Net Link States (Area 10)

Link ID         ADV Router      Age         Seq#        Checksum
0.0.0.0         2.2.2.2         625         0x80000001  0x0075C0
R1#

OSPF Not So Stubby Area (NSSA)
#

Tambahkan interface loopback di R1 dengan konfigurasi RIP.

R1(config-if)#interface Loopback1
R1(config-if)# ip address 11.11.11.1 255.255.255.255
R1(config-if)#interface Loopback2
R1(config-if)# ip address 11.11.11.2 255.255.255.255
R1(config-if)#interface Loopback3
R1(config-if)# ip address 11.11.11.3 255.255.255.255

R1(config-if)#router rip
R1(config-router)#ver 2
R1(config-router)#no auto-summary
R1(config-router)#net 11.0.0.0
R1(config)#router ospf 13
R1(config-router)#redistribute rip subnets

Hapus OSPF stub sebelumnya dan ganti dengan nssa.

R2(config-router)#no area 10 stub
R2(config-router)#area 10 nssa
*Mar 1 00:10:39.295: %OSPF-5-ADJCHG: Process 13, Nbr 2.2.2.2 on
FastEthernet0/0 from DOWN to DOWN, Neighbor Down: Adjacency forced to reset

Cek tabel routing R1. Internal area dari ospf area 100 muncul di stub router R1.

R1(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C    1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:01:48, FastEthernet0/0
    33.0.0.0/32 is subnetted, 4 subnets
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:01:48, FastEthernet0/0
O IA    33.33.33.7 [110/75] via 12.12.12.2, 00:01:48, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:01:48, FastEthernet0/0
O IA    33.33.33.8 [110/75] via 12.12.12.2, 00:01:48, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:01:49, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:01:49, FastEthernet0/0
    11.0.0.0/32 is subnetted, 3 subnets
C       11.11.11.3 is directly connected, Loopback3
C       11.11.11.2 is directly connected, Loopback2
C       11.11.11.1 is directly connected, Loopback1
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1(config-router)#

Cek tabel routing R3. External route dari RIP dan EIGRP sudah muncul di R1.

R3#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/75] via 23.23.23.2, 00:19:55, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:27:47, Serial1/0
    33.0.0.0/32 is subnetted, 8 subnets
C       33.33.33.1 is directly connected, Loopback1
C       33.33.33.3 is directly connected, Loopback3
C       33.33.33.2 is directly connected, Loopback2
C       33.33.33.5 is directly connected, Loopback5
C       33.33.33.4 is directly connected, Loopback4
C       33.33.33.7 is directly connected, Loopback7
C       33.33.33.6 is directly connected, Loopback6
C       33.33.33.8 is directly connected, Loopback8
    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O E2    11.11.11.3 [110/20] via 23.23.23.2, 00:19:11, Serial1/0
O E2    11.11.11.2 [110/20] via 23.23.23.2, 00:19:11, Serial1/0
O E2    11.11.11.1 [110/20] via 23.23.23.2, 00:19:11, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O IA    12.12.12.0 [110/74] via 23.23.23.2, 00:27:49, Serial1/0
R3#

Pada R1 belum ada default route sehingga belum bisa ping ke 33.33.33.1 - 33.33.33.4 pada network EIGRP pada R3 yang diredistribute ke OSPF.

R1#ping 33.33.33.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 33.33.33.1, timeout is 2 seconds:
.....
Success rate is 0 percent (0/5)
R1#

Caranya adalah dengan menambahkan konfigurasi pada ABR routernya yaitu R2.

R2(config-router)#area 10 nssa default-information-originate

R1#sh ip route
Gateway of last resort is 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     2.0.0.0/32 is subnetted, 1 subnets
O IA    2.2.2.2 [110/11] via 12.12.12.2, 00:27:01, FastEthernet0/0
     33.0.0.0/32 is subnetted, 4 subnets
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:27:01, FastEthernet0/0
O IA    33.33.33.7 [110/75] via 12.12.12.2, 00:27:01, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:27:01, FastEthernet0/0
O IA    33.33.33.8 [110/75] via 12.12.12.2, 00:27:02, FastEthernet0/0
     3.0.0.0/32 is subnetted, 1 subnets
O IA    3.3.3.3 [110/75] via 12.12.12.2, 00:27:02, FastEthernet0/0
     23.0.0.0/24 is subnetted, 1 subnets
O IA    23.23.23.0 [110/74] via 12.12.12.2, 00:27:03, FastEthernet0/0
     11.0.0.0/32 is subnetted, 3 subnets
C       11.11.11.3 is directly connected, Loopback3
C       11.11.11.2 is directly connected, Loopback2
C       11.11.11.1 is directly connected, Loopback1
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*N2 0.0.0.0/0 [110/1] via 12.12.12.2, 00:00:18, FastEthernet0/0
R1#ping 33.33.33.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 33.33.33.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/64/124 ms
R1#

Jika diinginkan internal route OSPF area lain tidak ditampilkan dalam database namun masih bisa mengirimkan External Route RIP nya, maka tambahkan nosummary pada ABR R2.

R2(config-router)#area 10 nssa no-summary

Cek tabel route R1.
R1#sh ip route
Gateway of last resort is 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     11.0.0.0/32 is subnetted, 3 subnets
C       11.11.11.3 is directly connected, Loopback3
C       11.11.11.2 is directly connected, Loopback2
C       11.11.11.1 is directly connected, Loopback1
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*IA 0.0.0.0/0 [110/11] via 12.12.12.2, 00:00:17, FastEthernet0/0
R1#ping 33.33.33.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 33.33.33.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 24/80/144 ms

Pastikan external route RIP dari R1 masih bisa diterima R3.

R3#sh ip route
Gateway of last resort is not set

     1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/75] via 23.23.23.2, 00:32:10, Serial1/0
     2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:40:02, Serial1/0
     33.0.0.0/32 is subnetted, 8 subnets
C       33.33.33.1 is directly connected, Loopback1
C       33.33.33.3 is directly connected, Loopback3
C       33.33.33.2 is directly connected, Loopback2
C       33.33.33.5 is directly connected, Loopback5
C       33.33.33.4 is directly connected, Loopback4
C       33.33.33.7 is directly connected, Loopback7
C       33.33.33.6 is directly connected, Loopback6
C       33.33.33.8 is directly connected, Loopback8
     3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
     23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
     11.0.0.0/32 is subnetted, 3 subnets
O E2    11.11.11.3 [110/20] via 23.23.23.2, 00:31:28, Serial1/0
O E2    11.11.11.2 [110/20] via 23.23.23.2, 00:31:28, Serial1/0
O E2    11.11.11.1 [110/20] via 23.23.23.2, 00:31:28, Serial1/0
     12.0.0.0/24 is subnetted, 1 subnets
O IA    12.12.12.0 [110/74] via 23.23.23.2, 00:40:06, Serial1/0
R3#ping 11.11.11.1

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 11.11.11.1, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 20/65/104 ms
R3#

OSPF External Route Type 1
#

R2#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/11] via 12.12.12.1, 00:02:05, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    33.0.0.0/32 is subnetted, 8 subnets
O E2    33.33.33.1 [110/20] via 23.23.23.3, 00:02:41, Serial1/0
O E2    33.33.33.3 [110/20] via 23.23.23.3, 00:02:41, Serial1/0
O E2    33.33.33.2 [110/20] via 23.23.23.3, 00:02:41, Serial1/0
O IA    33.33.33.5 [110/65] via 23.23.23.3, 00:02:41, Serial1/0
O E2    33.33.33.4 [110/20] via 23.23.23.3, 00:02:42, Serial1/0
O IA    33.33.33.7 [110/65] via 23.23.23.3, 00:02:42, Serial1/0
O IA    33.33.33.6 [110/65] via 23.23.23.3, 00:02:42, Serial1/0
O IA    33.33.33.8 [110/65] via 23.23.23.3, 00:02:42, Serial1/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:02:43, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O N2    11.11.11.3 [110/20] via 12.12.12.1, 00:02:08, FastEthernet0/0
O N2    11.11.11.2 [110/20] via 12.12.12.1, 00:02:08, FastEthernet0/0
O N2    11.11.11.1 [110/20] via 12.12.12.1, 00:02:08, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2#

R3#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/75] via 23.23.23.2, 00:01:14, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:01:47, Serial1/0
    33.0.0.0/32 is subnetted, 8 subnets
C       33.33.33.1 is directly connected, Loopback1
C       33.33.33.3 is directly connected, Loopback3
C       33.33.33.2 is directly connected, Loopback2
C       33.33.33.5 is directly connected, Loopback5
C       33.33.33.4 is directly connected, Loopback4
C       33.33.33.7 is directly connected, Loopback7
C       33.33.33.6 is directly connected, Loopback6
C       33.33.33.8 is directly connected, Loopback8
    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O E2    11.11.11.3 [110/20] via 23.23.23.2, 00:01:11, Serial1/0
O E2    11.11.11.2 [110/20] via 23.23.23.2, 00:01:11, Serial1/0
O E2    11.11.11.1 [110/20] via 23.23.23.2, 00:01:11, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O IA    12.12.12.0 [110/74] via 23.23.23.2, 00:01:49, Serial1/0

R3#sh ip route 11.11.11.1
Routing entry for 11.11.11.1/32
    Known via "ospf 14", distance 110, metric 20, type extern 2, forward
metric 75
    Last update from 23.23.23.2 on Serial1/0, 00:02:39 ago
    Routing Descriptor Blocks:
    * 23.23.23.2, from 2.2.2.2, 00:02:39 ago, via Serial1/0
        Route metric is 20, traffic share count is 1

Konfigurasi external route 1.

R1(config)#route-map TIPE_SATU
R1(config-route-map)#set metric-type type-1
R1(config-route-map)#router ospf 13
R1(config-router)#redistribute rip subnets route-map TIPE_SATU

Cek di R3.

R3#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O IA    1.1.1.1 [110/75] via 23.23.23.2, 00:01:01, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:01:01, Serial1/0
    33.0.0.0/32 is subnetted, 8 subnets
C       33.33.33.1 is directly connected, Loopback1
C       33.33.33.3 is directly connected, Loopback3
C       33.33.33.2 is directly connected, Loopback2
C       33.33.33.5 is directly connected, Loopback5
C       33.33.33.4 is directly connected, Loopback4
C       33.33.33.7 is directly connected, Loopback7
C       33.33.33.6 is directly connected, Loopback6
C       33.33.33.8 is directly connected, Loopback8
    3.0.0.0/32 is subnetted, 1 subnets
C 3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C 23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O E1    11.11.11.3 [110/95] via 23.23.23.2, 00:00:53, Serial1/0
O E1    11.11.11.2 [110/95] via 23.23.23.2, 00:00:53, Serial1/0
O E1    11.11.11.1 [110/95] via 23.23.23.2, 00:00:53, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O IA    12.12.12.0 [110/74] via 23.23.23.2, 00:01:03, Serial1/0
R3#

R2#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/11] via 12.12.12.1, 00:02:42, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    33.0.0.0/32 is subnetted, 8 subnets
O E2    33.33.33.1 [110/20] via 23.23.23.3, 00:02:42, Serial1/0
O E2    33.33.33.3 [110/20] via 23.23.23.3, 00:02:42, Serial1/0
O E2    33.33.33.2 [110/20] via 23.23.23.3, 00:02:42, Serial1/0
O IA    33.33.33.5 [110/65] via 23.23.23.3, 00:02:42, Serial1/0
O E2    33.33.33.4 [110/20] via 23.23.23.3, 00:02:44, Serial1/0
O IA    33.33.33.7 [110/65] via 23.23.23.3, 00:02:44, Serial1/0
O IA    33.33.33.6 [110/65] via 23.23.23.3, 00:02:44, Serial1/0
O IA    33.33.33.8 [110/65] via 23.23.23.3, 00:02:44, Serial1/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:02:46, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O N1    11.11.11.3 [110/31] via 12.12.12.1, 00:02:46, FastEthernet0/0
O N1    11.11.11.2 [110/31] via 12.12.12.1, 00:02:46, FastEthernet0/0
O N1    11.11.11.1 [110/31] via 12.12.12.1, 00:02:46, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2#

Jika sebelumnya metric sama-sama 20 pada tabel routing R2 dan R3, sekarang sudah berbeda.

OSPF Filtering Using Distribute List
#

R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
!
router ospf 1
 router-id 1.1.1.1
 network 0.0.0.0 255.255.255.255 area 0
!

R2
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
!
interface Serial1/0
 ip address 23.23.23.2 255.255.255.0
!
router ospf 2
 router-id 2.2.2.2
 network 0.0.0.0 255.255.255.255 area 0
!

R3
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 23.23.23.3 255.255.255.0
!
router ospf 3
 router-id 3.3.3.3
 network 0.0.0.0 255.255.255.255 area 0
!

Buat ip loopback yang bervariatif.
R1(config)#int lo1
R1(config-if)#ip add 11.11.11.1 255.255.255.255
R1(config-if)#int lo2
R1(config-if)#ip add 11.11.11.2 255.255.255.255
R1(config-if)#int lo3
R1(config-if)#ip add 11.11.11.3 255.255.255.255
R1(config-if)#int lo4
R1(config-if)#ip add 11.11.11.4 255.255.255.255
R1(config-if)#int lo5
R1(config-if)#ip add 11.11.11.5 255.255.255.255
R1(config-if)#int lo6
R1(config-if)#ip add 11.11.11.6 255.255.255.255

Cek routing table.

R2#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/11] via 12.12.12.1, 00:05:05, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:04:12, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 6 subnets
O       11.11.11.3 [110/11] via 12.12.12.1, 00:00:47, FastEthernet0/0
O       11.11.11.2 [110/11] via 12.12.12.1, 00:00:49, FastEthernet0/0
O       11.11.11.1 [110/11] via 12.12.12.1, 00:00:49, FastEthernet0/0
O       11.11.11.6 [110/11] via 12.12.12.1, 00:00:49, FastEthernet0/0
O       11.11.11.5 [110/11] via 12.12.12.1, 00:00:49, FastEthernet0/0
O       11.11.11.4 [110/11] via 12.12.12.1, 00:00:49, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2#

Filter yang ganjil saja menggunakan access-list dan konfigurasi distribute-list.

R2(config)#access-list 10 permit 0.0.0.1 255.255.255.254
R2(config)#router ospf 2
R2(config-router)#distribute-list 10 in

Cek tabel routing dan lihat hasilnya.

R2(config-router)#do sh 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 not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/11] via 12.12.12.1, 00:00:15, FastEthernet0/0
    2.0.0.0/32 is subnetted, 1 subnets
C       2.2.2.2 is directly connected, Loopback0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/65] via 23.23.23.3, 00:00:15, Serial1/0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    11.0.0.0/32 is subnetted, 3 subnets
O       11.11.11.3 [110/11] via 12.12.12.1, 00:00:15, FastEthernet0/0
O       11.11.11.1 [110/11] via 12.12.12.1, 00:00:16, FastEthernet0/0
O       11.11.11.5 [110/11] via 12.12.12.1, 00:00:16, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R2(config-router)#

Walau didalalam ip route tidak muncul, namun di ospf database masih muncul karena router dalam area yang sama memiliki database yang sama.

R2#sh ip ospf database

            OSPF Router with ID (2.2.2.2) (Process ID 2)

            Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum Link count
1.1.1.1         1.1.1.1         401         0x80000007  0x003446 8
2.2.2.2         2.2.2.2         617         0x80000002  0x000875 4
3.3.3.3         3.3.3.3         613         0x80000002  0x007365 3

            Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.1      1.1.1.1         662         0x80000001  0x004CB8
R2#

R1#sh ip ospf database

            OSPF Router with ID (1.1.1.1) (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         430         0x80000007  0x003446 8
2.2.2.2         2.2.2.2         648         0x80000002  0x000875 4
3.3.3.3         3.3.3.3         643         0x80000002  0x007365 3

            Net Link States (Area 0)

Link ID         ADV Router      Age         Seq#        Checksum
12.12.12.1      1.1.1.1         690         0x80000001  0x004CB8
R1#

OSPF Summarization – Area Range
#

R1
interface Loopback0
 ip address 1.1.1.1 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.1 255.255.255.0
!
router ospf 1
 router-id 1.1.1.1
 network 0.0.0.0 255.255.255.255 area 0
!

R2
interface Loopback0
 ip address 2.2.2.2 255.255.255.255
!
interface FastEthernet0/0
 ip address 12.12.12.2 255.255.255.0
!
interface Serial1/0
 ip address 23.23.23.2 255.255.255.0
!
router ospf 2
 router-id 2.2.2.2
 network 0.0.0.0 255.255.255.255 area 0
!

R3
interface Loopback0
 ip address 3.3.3.3 255.255.255.255
!
interface Serial1/0
 ip address 23.23.23.3 255.255.255.0
!
router ospf 3
 router-id 3.3.3.3
 network 0.0.0.0 255.255.255.255 area 0
!

Buat ip loopback untuk nantinya disummary.

R3(config)#int lo1
R3(config-if)#ip add 33.33.33.1 255.255.255.255
R3(config-if)#int lo2
R3(config-if)#ip add 33.33.33.2 255.255.255.255
R3(config-if)#int lo3
R3(config-if)#ip add 33.33.33.3 255.255.255.255
R3(config-if)#int lo4
R3(config-if)#ip add 33.33.33.4 255.255.255.255
R3(config-if)#int lo5
R3(config-if)#ip add 33.33.33.5 255.255.255.255
R3(config-if)#int lo6
R3(config-if)#ip add 33.33.33.6 255.255.255.255

R3(config)#router ospf 3
R3(config-router)#net 33.33.33.1 0.0.0.0 area 10
R3(config-router)#net 33.33.33.2 0.0.0.0 area 10
R3(config-router)#net 33.33.33.3 0.0.0.0 area 10
R3(config-router)#net 33.33.33.4 0.0.0.0 area 10
R3(config-router)#net 33.33.33.5 0.0.0.0 area 10
R3(config-router)#net 33.33.33.6 0.0.0.0 area 10

R1(config-router)#do sh 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 not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:04:12, FastEthernet0/0
    33.0.0.0/32 is subnetted, 6 subnets
O IA    33.33.33.1 [110/75] via 12.12.12.2, 00:00:20, FastEthernet0/0
O IA    33.33.33.3 [110/75] via 12.12.12.2, 00:00:20, FastEthernet0/0
O IA    33.33.33.2 [110/75] via 12.12.12.2, 00:00:20, FastEthernet0/0
O IA    33.33.33.5 [110/75] via 12.12.12.2, 00:00:20, FastEthernet0/0
O IA    33.33.33.4 [110/75] via 12.12.12.2, 00:00:21, FastEthernet0/0
O IA    33.33.33.6 [110/75] via 12.12.12.2, 00:00:12, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:02:51, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:04:15, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1(config-router)#

Konfigurasi summary di R3.

R3(config-router)#area 10 range 33.33.33.0 255.255.255.248
Cek tabel routing dan sudah tersummary.
R1(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:05:34, FastEthernet0/0
    33.0.0.0/29 is subnetted, 1 subnets
O IA    33.33.33.0 [110/75] via 12.12.12.2, 00:00:06, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:04:12, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:05:36, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1(config-router)#
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/75] via 23.23.23.2, 00:02:04, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:02:04, Serial1/0
    33.0.0.0/8 is variably subnetted, 7 subnets, 2 masks
C       33.33.33.1/32 is directly connected, Loopback1
O       33.33.33.0/29 is a summary, 00:02:04, Null0
C       33.33.33.3/32 is directly connected, Loopback3
C       33.33.33.2/32 is directly connected, Loopback2
C       33.33.33.5/32 is directly connected, Loopback5
C       33.33.33.4/32 is directly connected, Loopback4
C       33.33.33.6/32 is directly connected, Loopback6
    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O       12.12.12.0 [110/74] via 23.23.23.2, 00:02:06, Serial1/0
R3#

Jika ingin menghapus Null0 gunakan perintah dibawah.

R3(config-router)#no discard-route internal
R3(config-router)#do sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
O       1.1.1.1 [110/75] via 23.23.23.2, 00:00:09, Serial1/0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/65] via 23.23.23.2, 00:00:09, Serial1/0
    33.0.0.0/32 is subnetted, 6 subnets
C       33.33.33.1 is directly connected, Loopback1
C       33.33.33.3 is directly connected, Loopback3
C       33.33.33.2 is directly connected, Loopback2
C       33.33.33.5 is directly connected, Loopback5
C       33.33.33.4 is directly connected, Loopback4
C       33.33.33.6 is directly connected, Loopback6
    3.0.0.0/32 is subnetted, 1 subnets
C       3.3.3.3 is directly connected, Loopback0
    23.0.0.0/24 is subnetted, 1 subnets
C       23.23.23.0 is directly connected, Serial1/0
    12.0.0.0/24 is subnetted, 1 subnets
O       12.12.12.0 [110/74] via 23.23.23.2, 00:00:11, Serial1/0
R3(config-router)#

Dan Null0 sudah tiada.

OSPF Summarization – Summary Address
#

Masih menggunakan lab sebelumnya.

R3(config)#router eigrp 3
R3(config-router)#net 33.33.33.1 0.0.0.0
R3(config-router)#net 33.33.33.2 0.0.0.0
R3(config-router)#net 33.33.33.3 0.0.0.0
R3(config-router)#net 33.33.33.4 0.0.0.0
R3(config-router)#net 33.33.33.5 0.0.0.0
R3(config-router)#net 33.33.33.6 0.0.0.0
R3(config-router)#no auto-summary

R3(config)#no router ospf 3
*Mar 1 00:01:06.811: %OSPF-5-ADJCHG: Process 3, Nbr 2.2.2.2 on Serial1/0
from FULL to DOWN, Neighbor Down: Interface down or detached
R3(config)#router ospf 3
R3(config-router)#router-id 3.3.3.3
R3(config-router)#network 3.3.3.3 0.0.0.0 area 0
R3(config-router)#network 23.23.23.3 0.0.0.0 area 0 e
R3(config-router)#redistribute eigrp 3 subnets

R1#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:04:26, FastEthernet0/0
    33.0.0.0/32 is subnetted, 6 subnets
O E2    33.33.33.1 [110/20] via 12.12.12.2, 00:01:08, FastEthernet0/0
O E2    33.33.33.3 [110/20] via 12.12.12.2, 00:01:08, FastEthernet0/0
O E2    33.33.33.2 [110/20] via 12.12.12.2, 00:01:08, FastEthernet0/0
O E2    33.33.33.5 [110/20] via 12.12.12.2, 00:01:08, FastEthernet0/0
O E2    33.33.33.4 [110/20] via 12.12.12.2, 00:01:09, FastEthernet0/0
O E2    33.33.33.6 [110/20] via 12.12.12.2, 00:01:09, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:03:15, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:04:36, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#

Konfigurasi external route summary di R3.

R3(config-router)#summary-address 33.33.33.0 255.255.255.248

Cek lagi tabel routing R1.

R1#sh ip route
Gateway of last resort is not set

    1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
    2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:06:38, FastEthernet0/0
    33.0.0.0/29 is subnetted, 1 subnets
O E2    33.33.33.0 [110/20] via 12.12.12.2, 00:00:30, FastEthernet0/0
    3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:05:25, FastEthernet0/0
    23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:06:39, FastEthernet0/0
    12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
R1#

OSPF Path Selection
#

Masih menggunakan lab sebelumnya. Buat 1 ip loopback di R3 dan tidak usah diadvertise.

R3(config)#int lo11
R3(config-if)#ip add 113.113.113.113 255.255.255.255

Untuk mengakses loopback 113.113.113.113 yang tidak diadvertise, maka gunakan default route.

R3(config)#router ospf 3
R3(config-router)#default-information originate always

Cek tabel routing R1.

R1#sh 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 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:02:49, FastEthernet0/0
     33.0.0.0/29 is subnetted, 1 subnets
O E2    33.33.33.0 [110/20] via 12.12.12.2, 00:02:49, FastEthernet0/0
     3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:02:49, FastEthernet0/0
     23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:02:51, FastEthernet0/0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*E2 0.0.0.0/0 [110/1] via 12.12.12.2, 00:00:09, FastEthernet0/0
R1#ping 113.113.113.113

R1#sh 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 12.12.12.2 to network 0.0.0.0

     1.0.0.0/32 is subnetted, 1 subnets
C       1.1.1.1 is directly connected, Loopback0
     2.0.0.0/32 is subnetted, 1 subnets
O       2.2.2.2 [110/11] via 12.12.12.2, 00:02:49, FastEthernet0/0
     33.0.0.0/29 is subnetted, 1 subnets
O E2    33.33.33.0 [110/20] via 12.12.12.2, 00:02:49, FastEthernet0/0
     3.0.0.0/32 is subnetted, 1 subnets
O       3.3.3.3 [110/75] via 12.12.12.2, 00:02:49, FastEthernet0/0
     23.0.0.0/24 is subnetted, 1 subnets
O       23.23.23.0 [110/74] via 12.12.12.2, 00:02:51, FastEthernet0/0
     12.0.0.0/24 is subnetted, 1 subnets
C       12.12.12.0 is directly connected, FastEthernet0/0
O*E2 0.0.0.0/0 [110/1] via 12.12.12.2, 00:00:09, FastEthernet0/0
R1#ping 113.113.113.113

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 113.113.113.113, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/164/280 ms
R1#

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 113.113.113.113, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 16/164/280 ms
R1#

Default route sudah muncul.

OSPF Authentication
#

Ada 2 authentication dalam ospf.

Clear Text Authentication
MD5 Authentication

Konfigurasi Clear Text Authentication antara R1 dan R2.

R1(config)#int f0/0
R1(config-if)#ip ospf authentication
R1(config-if)#ip ospf authentication-key CISCO123

R2(config)#int f0/0
R2(config-if)#ip ospf authentication
R2(config-if)#ip ospf authentication-key CISCO123

R1(config-if)#do sh ip ospf int f0/0
FastEthernet0/0 is up, line protocol is up
    Internet Address 12.12.12.1/24, Area 0
    Process ID 1, Router ID 1.1.1.1, Network Type BROADCAST, Cost: 10
    Transmit Delay is 1 sec, State BDR, Priority 1
    Designated Router (ID) 2.2.2.2, Interface address 12.12.12.2
    Backup Designated router (ID) 1.1.1.1, Interface address 12.12.12.1
    Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
        oob-resync timeout 40
        Hello due in 00:00:00
    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 1
    Last flood scan time is 0 msec, maximum is 0 msec
    Neighbor Count is 1, Adjacent neighbor count is 1
        Adjacent with neighbor 2.2.2.2 (Designated Router)
    Suppress hello for 0 neighbor(s)
    Simple password authentication enabled
R1(config-if)#

Konfigurasi MD5 Authentication antara R2 dan R3.

R2(config-if)#int s1/0
R2(config-if)#ip ospf authentication message-digest
R2(config-if)#ip ospf message-digest-key 13 md5 CISCO123

R3(config)#int s1/0
R3(config-if)#ip ospf authentication message-digest
R3(config-if)#ip ospf message-digest-key 13 md5 CISCO123

R3(config-if)#do sh ip ospf int s1/0
Serial1/0 is up, line protocol is up
    Internet Address 23.23.23.3/24, Area 0
    Process ID 3, Router ID 3.3.3.3, Network Type POINT_TO_POINT, Cost: 64
    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 2/2, 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 2.2.2.2
    Suppress hello for 0 neighbor(s)
    Message digest authentication enabled
        Youngest key id is 13
R3(config-if)#

OSPF Path Selection
#

R1(config)#interface Loopback0
R1(config-if)#ip address 1.1.1.1 255.255.255.255
R1(config-if)#interface FastEthernet0/0
R1(config-if)#ip address 12.12.12.1 255.255.255.0
R1(config-if)#no sh
R1(config-if)#interface Serial1/0
R1(config-if)#ip address 13.13.13.1 255.255.255.0
R1(config-if)#no sh
R1(config-if)#router ospf 1
R1(config-router)#router-id 1.1.1.1
R1(config-router)#network 0.0.0.0 255.255.255.255 area 0

R2(config)#interface Loopback0
R2(config-if)#ip address 2.2.2.2 255.255.255.255
R2(config-if)#interface FastEthernet0/0
R2(config-if)#ip address 12.12.12.2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#interface FastEthernet0/1
R2(config-if)#ip address 23.23.23.2 255.255.255.0
R2(config-if)#no sh
R2(config-if)#router ospf 2
R2(config-router)#router-id 2.2.2.2
R2(config-router)#network 0.0.0.0 255.255.255.255 area 0

R3(config)#interface Loopback0
R3(config-if)#ip address 3.3.3.3 255.255.255.255
R3(config-if)#interface FastEthernet0/1
R3(config-if)#ip address 23.23.23.3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#interface Serial1/0
R3(config-if)#ip address 13.13.13.3 255.255.255.0
R3(config-if)#no sh
R3(config-if)#router ospf 3
R3(config-router)#router-id 3.3.3.3
R3(config-router)#network 0.0.0.0 255.255.255.255 area 0

Cek jalurnya ternyata melalui R2.

R1#traceroute 3.3.3.3

Type escape sequence to abort.
Tracing the route to 3.3.3.3

    1 12.12.12.2 208 msec 4 msec 8 msec
    2 23.23.23.3 276 msec 80 msec 216 msec
R1#sh ip route 3.3.3.3
Routing entry for 3.3.3.3/32
    Known via "ospf 1", distance 110, metric 21, type intra area
    Last update from 12.12.12.2 on FastEthernet0/0, 00:02:07 ago
    Routing Descriptor Blocks:
    * 12.12.12.2, from 3.3.3.3, 00:02:07 ago, via FastEthernet0/0
        Route metric is 21, traffic share count is 1
R1#

Karena ospf menggunakan bandwidth maka jalur yang lebih dipilih adalah yang melalui FastEthernet. FastEthernet mempunyai metric 10 didapat dari 100.000.000:10.000.000(bandwidth terendah 10Mbps).

Tertulis metric nya 21 didapat dari metric FastEthernet R1-R2 dan R2-R3 masingmasing 10 dan loopback R3 1 sehingga totalnya 21.

Coba shutdown FastEthernet pada R2.

R2(config)#interface FastEthernet0/0
R2(config-if)#shutdown

R1#sh ip route 3.3.3.3
Routing entry for 3.3.3.3/32
    Known via "ospf 1", distance 110, metric 65, type intra area
    Last update from 13.13.13.3 on Serial1/0, 00:00:18 ago
    Routing Descriptor Blocks:
    * 13.13.13.3, from 3.3.3.3, 00:00:18 ago, via Serial1/0
        Route metric is 65, traffic share count is 1
R1#

Maka jalurnya berpindah ke serial. Serial mempunyai metric 64 didapat dari 100.000.000:1.544.000(pembulatan bandwidth serial).

Metric 65 didapat dari link serial R1-R3 yaitu 64 dan loopback R3 1 totalnya 65.

Hidupkan lagi FastEthernet dan pastikan jalur kembali seperti semula.

R2(config)#interface FastEthernet0/0
R2(config-if)#no shutdown

R1#sh ip route 3.3.3.3
Routing entry for 3.3.3.3/32
    Known via "ospf 1", distance 110, metric 21, type intra area
    Last update from 12.12.12.2 on FastEthernet0/0, 00:00:55 ago
    Routing Descriptor Blocks:
    * 12.12.12.2, from 3.3.3.3, 00:00:55 ago, via FastEthernet0/0
        Route metric is 21, traffic share count is 1
R1#

Untuk memindahkan jalur ke Serial, ubah parameter bandwidth FastEthernet.

R1(config)#int fastEthernet0/0
R1(config-if)#bandwidth 100
R1#sh ip route 3.3.3.3
Routing entry for 3.3.3.3/32
    Known via "ospf 1", distance 110, metric 65, type intra area
    Last update from 13.13.13.3 on Serial1/0, 00:00:12 ago
    Routing Descriptor Blocks:
    * 13.13.13.3, from 3.3.3.3, 00:00:12 ago, via Serial1/0
        Route metric is 65, traffic share count is 1
R1#

Maka jalur berpindah ke Serial.

Chapters on Cisco - Artikel ini merupakan bagian dari sebuah seri.

Bagian 1: Dasar-dasar Jaringan

Bagian 6: Artikel ini

Bagian 7: BGP