IPv4 Routing with OSPF

Task - OSPF DR/BDR Election

All routers 1 through 10 have been pre-configured with IP addresses.
Configure OSPF Process-ID 1 on all routers with all interfaces with an IP address configured being in Area 0.
Use the network statement to activate OSPF.
Any new interface added must have OSPF activated automatically.
Ensure R3 is the DR and R10 is the BDR.
If R3 fails then R10 must become the DR.
Ensure R6 is the DR and R10 never becomes DR.
Verify the OSPF adjacency and the routing table.
Also verify the DR/BDR election on the link between R3 and R10 and between R6 and R10.

Solutions:

R1-R10:

router ospf 1
 network 0.0.0.0 255.255.255.255 area 0

R3:

interface GigabitEthernet0/0
 ip ospf priority 255

R6:

interface GigabitEthernet0/1
 ip ospf priority 255

R10:

interface GigabitEthernet0/0
 ip ospf priority 1

interface GigabitEthernet0/1
 ip ospf priority 0

Verification:

R1#sh ip ospf  neighbor 

Neighbor ID     Pri   State           Dead Time   Address         Interface
172.16.3.3        1   FULL/DR         00:00:38    172.16.13.3     GigabitEthernet0/1
172.16.2.2        1   FULL/DR         00:00:38    172.16.12.2     GigabitEthernet0/0


R1#sh ip ro ospf
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area 
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2
       i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
       ia - IS-IS inter area, * - candidate default, U - per-user static route
       o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR

Gateway of last resort is not set

      172.16.0.0/16 is variably subnetted, 29 subnets, 2 masks
O        172.16.2.2/32 [110/2] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.3.3/32 [110/2] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.4.4/32 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
                       [110/3] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.5.5/32 [110/3] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.6.6/32 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.7.7/32 [110/4] via 172.16.12.2, 00:01:48, GigabitEthernet0/0
O        172.16.8.8/32 [110/4] via 172.16.13.3, 00:01:38, GigabitEthernet0/1
O        172.16.9.9/32 [110/5] via 172.16.13.3, 00:01:28, GigabitEthernet0/1
                       [110/5] via 172.16.12.2, 00:01:28, GigabitEthernet0/0
O        172.16.10.10/32 [110/3] via 172.16.13.3, 00:01:58, GigabitEthernet0/1
O        172.16.23.0/24 [110/2] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.24.0/24 [110/2] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.25.0/24 [110/2] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.34.0/24 [110/2] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.36.0/24 [110/2] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.45.0/24 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
                        [110/3] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.46.0/24 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
                        [110/3] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.56.0/24 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
                        [110/3] via 172.16.12.2, 00:02:46, GigabitEthernet0/0
O        172.16.57.0/24 [110/3] via 172.16.12.2, 00:01:48, GigabitEthernet0/0
O        172.16.68.0/24 [110/3] via 172.16.13.3, 00:01:38, GigabitEthernet0/1
O        172.16.78.0/24 [110/4] via 172.16.13.3, 00:01:38, GigabitEthernet0/1
                        [110/4] via 172.16.12.2, 00:01:38, GigabitEthernet0/0
O        172.16.79.0/24 [110/4] via 172.16.12.2, 00:01:28, GigabitEthernet0/0
O        172.16.89.0/24 [110/4] via 172.16.13.3, 00:01:28, GigabitEthernet0/1
O        172.16.103.0/24 [110/2] via 172.16.13.3, 00:02:36, GigabitEthernet0/1
O        172.16.106.0/24 [110/3] via 172.16.13.3, 00:02:36, GigabitEthernet0/1

R6#sh ip ospf  interface g0/1
GigabitEthernet0/1 is up, line protocol is up 
  Internet Address 172.16.106.6/24, Area 0, Attached via network Statement
  Process ID 1,  router ID 172.16.6.6, network Type BROADCAST, Cost: 1
  Topology-MTID    Cost    Disabled    Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State DR, Priority 255
  Designated  router (ID) 172.16.6.6, Interface address 172.16.106.6
  No backup designated router on this network
  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 1/2/2, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 2, maximum is 2
  Last flood scan time is 1 msec, maximum is 1 msec
 neighbor Count is 1, Adjacent neighbor count is 1 
    Adjacent with neighbor 172.16.10.10
  Suppress hello for 0 neighbor(s)

R10#sh ip ospf interface g0/1
GigabitEthernet0/1 is up, line protocol is up 
  Internet Address 172.16.106.10/24, Area 0, Attached via network Statement
  Process ID 1,  router ID 172.16.10.10, network Type BROADCAST, Cost: 1
  Topology-MTID    Cost    Disabled    Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State DROTHER, Priority 0
  Designated  router (ID) 172.16.6.6, Interface address 172.16.106.6
  No backup designated router on this network
  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 1/2/2, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 1, maximum is 2
  Last flood scan time is 0 msec, maximum is 0 msec
 neighbor Count is 1, Adjacent neighbor count is 1 
    Adjacent with neighbor 172.16.6.6  (Designated Router)
  Suppress hello for 0 neighbor(s)

R10#sh ip ospf interface g0/0
GigabitEthernet0/0 is up, line protocol is up 
  Internet Address 172.16.103.10/24, Area 0, Attached via network Statement
  Process ID 1,  router ID 172.16.10.10, network Type BROADCAST, Cost: 1
  Topology-MTID    Cost    Disabled    Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State BDR, Priority 1
  Designated  router (ID) 172.16.3.3, Interface address 172.16.103.3
  Backup Designated router (ID) 172.16.10.10, Interface address 172.16.103.10
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:08
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1/1, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 2, maximum is 2
  Last flood scan time is 1 msec, maximum is 1 msec
 neighbor Count is 1, Adjacent neighbor count is 1 
    Adjacent with neighbor 172.16.3.3  (Designated Router)
  Suppress hello for 0 neighbor(s)

R3#sh ip ospf  interface g0/0
GigabitEthernet0/0 is up, line protocol is up 
  Internet Address 172.16.103.3/24, Area 0, Attached via network Statement
  Process ID 1,  router ID 172.16.3.3, network Type BROADCAST, Cost: 1
  Topology-MTID    Cost    Disabled    Shutdown      Topology Name
        0           1         no          no            Base
  Transmit Delay is 1 sec, State DR, Priority 255
  Designated  router (ID) 172.16.3.3, Interface address 172.16.103.3
  Backup Designated router (ID) 172.16.10.10, Interface address 172.16.103.10
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:02
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1/1, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 2, maximum is 2
  Last flood scan time is 0 msec, maximum is 1 msec
 neighbor Count is 1, Adjacent neighbor count is 1 
    Adjacent with neighbor 172.16.10.10  (Backup Designated Router)
  Suppress hello for 0 neighbor(s)