R1> R1>en R1# R1#show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 10.0.1.254 YES manual up up GigabitEthernet0/1 unassigned YES unset administratively down down GigabitEthernet0/2 unassigned YES unset administratively down down Serial0/0/0 unassigned YES unset administratively down down Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down R1#
R1 G0/0 is configured. R1 S0/0/0 is not configured.
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R1# R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)# R1(config)# R1(config)#int s0/0/0 R1(config-if)#ip address 192.168.12.1 % Incomplete command. R1(config-if)#ip address 192.168.12.1 255.255.255.252 R1(config-if)#
S0/0/0 is now configured.
Next, configure the serial connection between R1 and R2 (clock rate of 128000). Need to confirm which router is the DCE.
R1# R1#show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 10.0.1.254 YES manual up up GigabitEthernet0/1 unassigned YES unset administratively down down GigabitEthernet0/2 unassigned YES unset administratively down down Serial0/0/0 192.168.12.1 YES manual administratively down down Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down
S0/0/0 still shows down. That’s because I forgot to turn off shutdown.
R1# R1#en R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#int s0/0/0 R1(config-if)# R1(config-if)#no shutdown
%LINK-5-CHANGED: Interface Serial0/0/0, changed state to down R1(config-if)# R1(config-if)# R1(config-if)#end R1# %SYS-5-CONFIG_I: Configured from console by console
R1#show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 10.0.1.254 YES manual up up GigabitEthernet0/1 unassigned YES unset administratively down down GigabitEthernet0/2 unassigned YES unset administratively down down Serial0/0/0 192.168.12.1 YES manual down down Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down R1#
Looks good. Still shows down because R2 is not configured yet.
Now we configure R2’s S0/0/0 interface the same way.
R2> R2>en R2#show ip interface brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 192.168.245.1 YES manual up up GigabitEthernet0/1 unassigned YES unset administratively down down GigabitEthernet0/2 unassigned YES unset administratively down down Serial0/0/0 unassigned YES unset administratively down down Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down R2# R2#conf t Enter configuration commands, one per line. End with CNTL/Z. R2(config)# R2(config)#int s0/0/0 R2(config-if)# R2(config-if)#ip address 192.168.12.2 255.255.255.252 R2(config-if)# R2(config-if)# R2(config-if)# R2(config-if)#do show controllers s0/0/0 Interface Serial0/0/0 Hardware is PowerQUICC MPC860 DTE V.35 TX and RX clocks detected idb at 0x81081AC4, driver data structure at 0x81084AC0 SCC Registers: General [GSMR]=0x2:0x00000000, Protocol-specific [PSMR]=0x8 Events [SCCE]=0x0000, Mask [SCCM]=0x0000, Status [SCCS]=0x00 Transmit on Demand [TODR]=0x0, Data Sync [DSR]=0x7E7E Interrupt Registers: Config [CICR]=0x00367F80, Pending [CIPR]=0x0000C000 Mask [CIMR]=0x00200000, In-srv [CISR]=0x00000000 Command register [CR]=0x580 Port A [PADIR]=0x1030, [PAPAR]=0xFFFF [PAODR]=0x0010, [PADAT]=0xCBFF Port B [PBDIR]=0x09C0F, [PBPAR]=0x0800E [PBODR]=0x00000, [PBDAT]=0x3FFFD Port C [PCDIR]=0x00C, [PCPAR]=0x200 [PCSO]=0xC20, [PCDAT]=0xDF2, [PCINT]=0x00F Receive Ring rmd(68012830): status 9000 length 60C address 3B6DAC4 rmd(68012838): status B000 length 60C address 3B6D444 Transmit Ring tmd(680128B0): status 0 length 0 address 0
R2(config-if)# %LINK-5-CHANGED: Interface Serial0/0/0, changed state to up
R2(config-if)# R2(config-if)# R2(config-if)#exi %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0/0, changed state to R2(config-if)# R2(config-if)#exit R2(config)# R2(config)#do show ip int brief Interface IP-Address OK? Method Status Protocol GigabitEthernet0/0 192.168.245.1 YES manual up up GigabitEthernet0/1 unassigned YES unset administratively down down GigabitEthernet0/2 unassigned YES unset administratively down down Serial0/0/0 192.168.12.2 YES manual up up Serial0/0/1 unassigned YES unset administratively down down Vlan1 unassigned YES unset administratively down down R2(config)#
Great. IP addresses are configured. We confirmed R2’s S0/0/0 is DTE DTE V.35 TX and RX clocks detected, which we already knew since R1 was confirmed DCE.
Now let’s configured OSPF on R1 and R2.
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R2(config)#do show ip protocol
Routing Protocol is "ospf 1" Outgoing update filter list for all interfaces is not set Incoming update filter list for all interfaces is not set Router ID 192.168.245.1 Number of areas in this router is 1. 1 normal 0 stub 0 nssa Maximum path: 4 Routing for Networks: 192.168.245.1 0.0.0.0 area 0 Routing Information Sources: Gateway Distance Last Update 192.168.34.1 110 00:09:52 192.168.245.1 110 00:09:52 192.168.245.2 110 00:09:52 Distance: (default is 110)
OSPF is already running on the G0/0 interface as shown here 192.168.245.1 0.0.0.0 area 0.
There are two methods that I can recall for enabling ospf.
We can use
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R2(config)#router ospf 1 R2(config-router)# R2(config-router)# R2(config-router)#network 192.168.12.0 0.0.0.3 area 0
Or we can simply do (given that we’re on the correct interface).
1
R2(config-if)#ip ospf 1 area 0
We’re going to use the first method because it’s consistent with what has already occurred on R2’s G0/0 interface.
R2’s OSPF protocols should be enabled now.
Let’s do the same for R1.
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R1> R1>en R1#show ip protocols R1# R1#
No protocol has been configured…
We can configure G0/0 and G0/1 like so
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R1#conf t Enter configuration commands, one per line. End with CNTL/Z. R1(config)#router os? ospf R1(config)#router ospf 1 R1(config-router)# R1(config-router)#network 192.168.12.0 0.0.0.3 area 0 R1(config-router)#network 10:21:19: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.245.1 on Serial0/0/0 from LOADING to FULL, Loadi R1(config-router)# R1(config-router)#network 10.0.1.0 0.0.0.3 area 0 R1(config-router)#
However, I think a better method would be to enable OSPF directly on interfaces instead of specifying network and wildmasks.
While not done in this lab, alternatively, we could’ve gone this route as follows:
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R1(config)#int g0/0 R1(config-if)#ip ospf 1 area 0 R1(config-if)# R1(config-if)# R1(config-if)#int s0/0/0 R1(config-if)#ip ospf 1 area 0
In any case, let’s confirm both interfaces.
In s0/0/0,
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R1(config)#do show ip ospf int s0/0/0
Serial0/0/0 is up, line protocol is up Internet address is 192.168.12.1/30, Area 0 Process ID 1, Router ID 192.168.12.1, 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 Hello due in 00:00:09 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 192.168.245.1 Suppress hello for 0 neighbor(s)
R1 is showing a Process ID 1, Router ID 192.168.12.1, Network Type POINT-TO-POINT, Cost: 64
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R1(config)#do show ip ospf int g0/0 %OSPF: OSPF not enabled on GigabitEthernet0/0 R1(config)#
What’s wrong?
If we look at the diagram again, it looks like I misconfigured G0/0 wildcard mask to be R1(config-router)#network 10.0.1.0 0.0.0.3 area 0, when it should be R1(config-router)#network 10.0.1.0 0.0.0.255 area 0.
I fixed it below.
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R1(config)#router ospf 1 R1(config-router)# R1(config-router)#network 10.0.1.0 0.0.0.255 area 0 R1(config-router)# R1(config-router)#exit R1(config)# R1(config)#do show ip ospf int g0/0
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GigabitEthernet0/0 is up, line protocol is up Internet address is 10.0.1.254/24, Area 0 Process ID 1, Router ID 192.168.12.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 192.168.12.1, Interface address 10.0.1.254 No backup designated router on this network Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:05 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 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) R1(config)#
R1(config)#do 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, E - EGP i - IS-IS, 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
10.0.0.0/8 is variably subnetted, 2 subnets, 2 masks C 10.0.1.0/24 is directly connected, GigabitEthernet0/0 L 10.0.1.254/32 is directly connected, GigabitEthernet0/0 192.168.12.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.12.0/30 is directly connected, Serial0/0/0 L 192.168.12.1/32 is directly connected, Serial0/0/0 192.168.34.0/30 is subnetted, 1 subnets O 192.168.34.0/30 [110/66] via 192.168.12.2, 00:09:46, Serial0/0/0 192.168.245.0/29 is subnetted, 1 subnets O 192.168.245.0/29 [110/65] via 192.168.12.2, 00:09:46, Serial0/0/0
I can see two OSPF routes, but it looks like we’re missing some specifically to 10.0.2.0/24 and 203.0.113.0/30.
Step 2 says “Only R3 has a route to 10.0.2.0/24. Why? Fix the problem.”
I’m pretty confident we configured R1 and R2 correctly. So the issue should lie anywhere on the path before that.
Let’s check R4 first.
Could there be an issue between R3 and R4’s OSPF adjacency?
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R4> R4>en R4#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface 192.168.245.1 1 FULL/BDR 00:00:39 192.168.245.1 GigabitEthernet0/0 192.168.34.1 1 FULL/BDR 00:00:39 192.168.34.1 GigabitEthernet0/1
Initially, it looks good. State is FULL/BDR to R3.
Let’s check the OSPF interface settings on R4 G0/1.
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R4#show ip ospf int g0/1
GigabitEthernet0/1 is up, line protocol is up Internet address is 192.168.34.2/30, Area 0 Process ID 1, Router ID 192.168.245.2, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 192.168.245.2, Interface address 192.168.34.2 Backup Designated Router (ID) 192.168.34.1, Interface address 192.168.34.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:03 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 192.168.34.1 (Backup Designated Router) Suppress hello for 0 neighbor(s)
Now let’s check R3’s interface and see if there are any common OSPF incompatibilities.
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R3> R3>en R3#show ip ospf int g0/1
GigabitEthernet0/1 is up, line protocol is up Internet address is 192.168.34.1/30, Area 0 Process ID 1, Router ID 192.168.34.1, Network Type POINT-TO-POINT, Cost: 1 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 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 192.168.245.2 Suppress hello for 0 neighbor(s)
Right off the bat, I can see a NETWORK misconfiguration. One is POINT-TO-POINT, and another is BROADCAST.
We will disable R3’s point-to-point, so that it’ll default to broadcast.
R3> R3>en R3#conf t Enter configuration commands, one per line. End with CNTL/Z. R3(config)# R3(config)#int g0/1 R3(config-if)#no ip ospf ? <1-65535> Process ID authentication Enable authentication authentication-key Authentication password (key) cost Interface cost dead-interval Interval after which a neighbor is declared dead hello-interval Time between HELLO packets message-digest-key Message digest authentication password (key) network Network type priority Router priority R3(config-if)#no ip ospf network ? <cr> R3(config-if)#no ip ospf network point-to-point R3(config-if)# 11:05:35: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.245.2 on GigabitEthernet0/1 from FULL to DOWN, Neighbor Down: Interface down or detached
11:05:35: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.245.2 on GigabitEthernet0/1 from LOADING to FULL, Loading Done
R3(config-if)#
Check the configuration again.
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R3(config-if)#do show ip ospf int g0/1
GigabitEthernet0/1 is up, line protocol is up Internet address is 192.168.34.1/30, Area 0 Process ID 1, Router ID 192.168.34.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State BDR, Priority 1 Designated Router (ID) 192.168.245.2, Interface address 192.168.34.2 Backup Designated Router (ID) 192.168.34.1, Interface address 192.168.34.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:08 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 192.168.245.2 (Designated Router) Suppress hello for 0 neighbor(s)
It is now Process ID 1, Router ID 192.168.34.1, Network Type BROADCAST, Cost: 1
In R4, let’s see if OSPF is configured properly to route to 10.0.2.0.
R4#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, E - EGP i - IS-IS, 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
10.0.0.0/24 is subnetted, 2 subnets O 10.0.1.0/24 [110/66] via 192.168.245.1, 00:37:36, GigabitEthernet0/0 O 10.0.2.0/24 [110/2] via 192.168.34.1, 00:00:51, GigabitEthernet0/1 192.168.12.0/30 is subnetted, 1 subnets O 192.168.12.0/30 [110/65] via 192.168.245.1, 00:49:57, GigabitEthernet0/0 192.168.34.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.34.0/30 is directly connected, GigabitEthernet0/1 L 192.168.34.2/32 is directly connected, GigabitEthernet0/1 192.168.245.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.245.0/29 is directly connected, GigabitEthernet0/0 L 192.168.245.2/32 is directly connected, GigabitEthernet0/0
Yup. O 10.0.2.0/24 [110/2] via 192.168.34.1, 00:00:51, GigabitEthernet0/1
Pinging PC1 to PC2 should work now.
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C:\>ping 10.0.2.1
Pinging 10.0.2.1 with 32 bytes of data:
Request timed out. Reply from 10.0.2.1: bytes=32 time=2ms TTL=124 Reply from 10.0.2.1: bytes=32 time=2ms TTL=124 Reply from 10.0.2.1: bytes=32 time=2ms TTL=124
Ping statistics for 10.0.2.1: Packets: Sent = 4, Received = 3, Lost = 1 (25% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms
C:\>
Step 3.
R2 and R4 won’t become OSPF neighbors with R5. Why? Fix the problem.
Let’s check R4 g0/0 configurations.
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R4#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface 192.168.245.1 1 FULL/BDR 00:00:33 192.168.245.1 GigabitEthernet0/0 192.168.34.1 1 FULL/BDR 00:00:38 192.168.34.1 GigabitEthernet0/1 R4#
R5 isn’t present.
This is R4’s OSPF interface config.
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R4#show ip ospf int g0/0
GigabitEthernet0/0 is up, line protocol is up Internet address is 192.168.245.2/29, Area 0 Process ID 1, Router ID 192.168.245.2, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 192.168.245.2, Interface address 192.168.245.2 Backup Designated Router (ID) 192.168.245.1, Interface address 192.168.245.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:07 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 192.168.245.1 (Backup Designated Router) Suppress hello for 0 neighbor(s)
Neighbor ID Pri State Dead Time Address Interface 192.168.12.1 0 FULL/ - 00:00:32 192.168.12.1 Serial0/0/0 192.168.245.2 1 FULL/DR 00:00:36 192.168.245.2 GigabitEthernet0/0 R2# R2# R2#show ip ospf int g0/0
GigabitEthernet0/0 is up, line protocol is up Internet address is 192.168.245.1/29, Area 0 Process ID 1, Router ID 192.168.245.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State BDR, Priority 1 Designated Router (ID) 192.168.245.2, Interface address 192.168.245.2 Backup Designated Router (ID) 192.168.245.1, Interface address 192.168.245.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:09 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 192.168.245.2 (Designated Router) Suppress hello for 0 neighbor(s) R2#
R2 is also not showing R5 as a neighbor.
From here, we can do some preliminary checklists.
The IP address in R2 and R4’s are in the same subnet mask.
GigabitEthernet0/0 is up, line protocol is up Internet address is 192.168.245.3/29, Area 0 Process ID 1, Router ID 203.0.113.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 203.0.113.1, Interface address 192.168.245.3 No backup designated router on this network Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 Hello due in 00:00:02 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 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) R5#
As expected, no neighbors.
The internet address is within the correct subnet.
It has matching area 0.
Network type matches R2 and R4.
The issue is here: Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5.
GigabitEthernet0/0 is up, line protocol is up Internet address is 192.168.245.3/29, Area 0 Process ID 1, Router ID 203.0.113.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 203.0.113.1, Interface address 192.168.245.3 No backup designated router on this network Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5 Hello due in 00:00:02 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 0, Adjacent neighbor count is 0 Suppress hello for 0 neighbor(s) R5# R5# R5#conf t Enter configuration commands, one per line. End with CNTL/Z. R5(config)# R5(config)#int g0/0 R5(config-if)# R5(config-if)#ip os? ospf R5(config-if)#ip ospf ? <1-65535> Process ID authentication Enable authentication authentication-key Authentication password (key) cost Interface cost dead-interval Interval after which a neighbor is declared dead hello-interval Time between HELLO packets message-digest-key Message digest authentication password (key) network Network type priority Router priority R5(config-if)#no ip ospf dead-interval R5(config-if)#no ip ospf hello-interval R5(config-if)# R5(config-if)# R5(config-if)# 11:14:56: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.245.1 on GigabitEthernet0/0 from LOADING to FULL, Loading Done
11:14:56: %OSPF-5-ADJCHG: Process 1, Nbr 192.168.245.2 on GigabitEthernet0/0 from LOADING to FULL, Loading Done
R5(config-if)# R5(config-if)#exit R5(config)#do show ip ospf int g0/0
GigabitEthernet0/0 is up, line protocol is up Internet address is 192.168.245.3/29, Area 0 Process ID 1, Router ID 203.0.113.1, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DR, Priority 1 Designated Router (ID) 203.0.113.1, Interface address 192.168.245.3 Backup Designated Router (ID) 192.168.245.1, Interface address 192.168.245.1 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:05 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 2, Adjacent neighbor count is 2 Adjacent with neighbor 192.168.245.1 (Backup Designated Router) Adjacent with neighbor 192.168.245.2 Suppress hello for 0 neighbor(s)
We reset the hello and dead timers and confirmed. Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
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R5(config)#do show ip ospf ne
Neighbor ID Pri State Dead Time Address Interface 192.168.245.1 1 FULL/BDR 00:00:32 192.168.245.1 GigabitEthernet0/0 192.168.245.2 1 FULL/DROTHER 00:00:32 192.168.245.2 GigabitEthernet0/0 R5(config)#
We can see that R5 now has neighbors.
Step 4
PC1 and PC2 can’t ping the external server 8.8.8.8. Why? Fix the problem.
Confirm the problem.
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C:\>ping 8.8.8.8
Pinging 8.8.8.8 with 32 bytes of data:
Reply from 10.0.1.254: Destination host unreachable. Reply from 10.0.1.254: Destination host unreachable. Reply from 10.0.1.254: Destination host unreachable. Reply from 10.0.1.254: Destination host unreachable.
Ping statistics for 8.8.8.8: Packets: Sent = 4, Received = 0, Lost = 4 (100% loss),
C:\>
Yep.
Let’s check R5 is advertising it’s OSPF Type 5 LSA.
R5(config)# R5(config)#do show running Building configuration...
Current configuration : 899 bytes ! version 15.1 no service timestamps log datetime msec no service timestamps debug datetime msec no service password-encryption ! hostname R5 ! ! ! ! ! ! ! ! no ip cef no ipv6 cef ! ! ! ! license udi pid CISCO2911/K9 sn FTX1524WH54- ! ! ! ! ! ! ! ! ! ! ! spanning-tree mode pvst ! ! ! ! ! ! interface GigabitEthernet0/0 ip address 192.168.245.3 255.255.255.248 duplex auto speed auto ! interface GigabitEthernet0/1 no ip address duplex auto speed auto shutdown ! interface GigabitEthernet0/2 no ip address duplex auto speed auto shutdown ! interface GigabitEthernet0/0/0 ip address 203.0.113.1 255.255.255.252 ! interface Vlan1 no ip address shutdown ! router ospf 1 log-adjacency-changes network 192.168.245.3 0.0.0.0 area 0 default-information originate ! ip classless ! ip flow-export version 9 --More--
We can see that R5 has default-information originate enabled. So no issues here.
R5(config)#do sh 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, E - EGP i - IS-IS, 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
10.0.0.0/24 is subnetted, 2 subnets O 10.0.1.0/24 [110/66] via 192.168.245.1, 00:05:23, GigabitEthernet0/0 O 10.0.2.0/24 [110/3] via 192.168.245.2, 00:05:13, GigabitEthernet0/0 192.168.12.0/30 is subnetted, 1 subnets O 192.168.12.0/30 [110/65] via 192.168.245.1, 00:05:23, GigabitEthernet0/0 192.168.34.0/30 is subnetted, 1 subnets O 192.168.34.0/30 [110/2] via 192.168.245.2, 00:05:13, GigabitEthernet0/0 192.168.245.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.245.0/29 is directly connected, GigabitEthernet0/0 L 192.168.245.3/32 is directly connected, GigabitEthernet0/0 203.0.113.0/24 is variably subnetted, 2 subnets, 2 masks C 203.0.113.0/30 is directly connected, GigabitEthernet0/0/0 L 203.0.113.1/32 is directly connected, GigabitEthernet0/0/0
R5(config)#ip route 0.0.0.0 0.0.0.0 203.0.113.2 R5(config)# R5(config)# R5(config)#do 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, E - EGP i - IS-IS, 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 203.0.113.2 to network 0.0.0.0
10.0.0.0/24 is subnetted, 2 subnets O 10.0.1.0/24 [110/66] via 192.168.245.1, 00:09:44, GigabitEthernet0/0 O 10.0.2.0/24 [110/3] via 192.168.245.2, 00:09:34, GigabitEthernet0/0 192.168.12.0/30 is subnetted, 1 subnets O 192.168.12.0/30 [110/65] via 192.168.245.1, 00:09:44, GigabitEthernet0/0 192.168.34.0/30 is subnetted, 1 subnets O 192.168.34.0/30 [110/2] via 192.168.245.2, 00:09:34, GigabitEthernet0/0 192.168.245.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.245.0/29 is directly connected, GigabitEthernet0/0 L 192.168.245.3/32 is directly connected, GigabitEthernet0/0 203.0.113.0/24 is variably subnetted, 2 subnets, 2 masks C 203.0.113.0/30 is directly connected, GigabitEthernet0/0/0 L 203.0.113.1/32 is directly connected, GigabitEthernet0/0/0 S* 0.0.0.0/0 [1/0] via 203.0.113.2
R5(config)#
We configured it as shown S* 0.0.0.0/0 [1/0] via 203.0.113.2
Pinging works now from PC1 to 8.8.8.8.
1 2 3 4 5 6 7 8 9 10 11 12 13
Pinging 8.8.8.8 with 32 bytes of data:
Request timed out. Reply from 8.8.8.8: bytes=32 time=2ms TTL=252 Reply from 8.8.8.8: bytes=32 time=2ms TTL=252 Reply from 8.8.8.8: bytes=32 time=2ms TTL=252
Ping statistics for 8.8.8.8: Packets: Sent = 4, Received = 3, Lost = 1 (25% loss), Approximate round trip times in milli-seconds: Minimum = 2ms, Maximum = 2ms, Average = 2ms
C:\>
We can even check R1’s route table to confirm that OSPF has added a default route.
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, E - EGP i - IS-IS, 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 192.168.12.2 to network 0.0.0.0
10.0.0.0/8 is variably subnetted, 3 subnets, 2 masks C 10.0.1.0/24 is directly connected, GigabitEthernet0/0 L 10.0.1.254/32 is directly connected, GigabitEthernet0/0 O 10.0.2.0/24 [110/67] via 192.168.12.2, 00:11:03, Serial0/0/0 192.168.12.0/24 is variably subnetted, 2 subnets, 2 masks C 192.168.12.0/30 is directly connected, Serial0/0/0 L 192.168.12.1/32 is directly connected, Serial0/0/0 192.168.34.0/30 is subnetted, 1 subnets O 192.168.34.0/30 [110/66] via 192.168.12.2, 00:11:03, Serial0/0/0 192.168.245.0/29 is subnetted, 1 subnets O 192.168.245.0/29 [110/65] via 192.168.12.2, 00:11:03, Serial0/0/0 O*E2 0.0.0.0/0 [110/1] via 192.168.12.2, 00:01:34, Serial0/0/0
Confirmed: O*E2 0.0.0.0/0 [110/1] via 192.168.12.2, 00:01:34, Serial0/0/0
Step 5
Examine the LSDB. What LSAs are present?
If configured correctly. All routers should have the same LSDB
R1#show ip ospf database OSPF Router with ID (192.168.12.1) (Process ID 1)
Router Link States (Area 0)
Link ID ADV Router Age Seq# Checksum Link count 192.168.12.1 192.168.12.1 1694 0x80000004 0x00ee82 3 192.168.34.1 192.168.34.1 1296 0x80000009 0x00ea12 2 192.168.245.2 192.168.245.2 737 0x80000009 0x005c3f 2 192.168.245.1 192.168.245.1 732 0x80000007 0x004884 3 203.0.113.1 203.0.113.1 732 0x80000005 0x00828b 1
Net Link States (Area 0) Link ID ADV Router Age Seq# Checksum 192.168.34.2 192.168.245.2 1576 0x80000005 0x00f326 192.168.245.3 203.0.113.1 737 0x80000002 0x00892d
Type-5 AS External Link States Link ID ADV Router Age Seq# Checksum Tag 0.0.0.0 203.0.113.1 154 0x80000001 0x00d2c1 1 R1#
Each router advertises its own LSA (Type 1) The network link states are Type 2s. The DR of each multi-access network should generate a Type 2. And we can expect one type 5 AS-External Link States.
