Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.1.x

PDF

Cisco Catalyst 9800 Series Wireless Controller Software Configuration Guide, Cisco IOS XE 26.1.x

OSPF protocols

Want to summarize with AI?

Log in

Explains OSPF protocols, their key functions as link-state routing protocols, core authentication methods, notable features and enhancements in OSPF deployments.


An OSPF protocol is a link-state routing protocol that

  • calculates the best path through a network using the shortest path first algorithm

  • enables dynamic route selection for IP networks, and

  • supports multiple authentication methods for secure device communication.

OSPF is a widely used Interior Gateway Protocol (IGP). Each device can verify the identity of the other devices it communicates with.

OSPF supports several types of authentication:

  • Simple password authentication: Each device uses a clear-text password configured for authentication with other devices. However, this method is not secure as the password appears in configuration files and OSPF messages. This is not a secure way to configure devices.

  • MD5 authentication: This method uses the MD5 algorithm to compute a hash value from the OSPF packet contents and a password.

Note

Starting with Cisco IOS XE 17.13.1, OSPFv2 and ECMP are supported.


Configure OSPF

Set up Open Shortest Path First (OSPF) to enable dynamic routing across device interfaces.

Procedure

1.

Configure a clear-text password (or) message digest key in an OSPF-enabled interface.

2.

Create an OSPF routing process.

3.

Specify the range of IP addresses to associate with the routing process.

4.

Assign area IDs to be associated with that range.

What to do next

What to do next

Note

To enable OSPF in SVI interfaces, you must enable Multicast over Multicast (MOM) using the wireless multicast ip-address command. This allows OSPF to establish neighbor adjacencies between SVIs.

These topics describe procedures to configure routing protocol:


Configure OSPF interfaces (GUI)

Enable and customize OSPF parameters on specific interfaces through the GUI.

Procedure

1.

Choose Configuration > Interface > Ethernet and select an interface to configure it with OSPF settings.

2.

In the Configure Interface window, ensure that you have configured an IP address, subnet mask and optionally a secondary IP address.

3.

In the OSPF section, enter the Process ID to enable OSPF on the interface.

4.

Enable the BFD to create a Bidirectional Forwarding Detection session between two systems. BFD provides a short-duration method of detecting failures in the forwarding path between two adjacent peers.

5.

Select the Dead Interval Minimal and enter the number of seconds in the Hello Multiplier field to set the interval at which at least one hello packet must be received, or else the neighbor is considered down.

6.

Select Message Digest Authentication to configure the authentication supported by OSPF.

7.

Under the Message Digest Authentication- Key Map association box, enter the Key, Type and Password.

8.

Click Save & Apply to Device.

Note

To configure OSPF in SVI interfaces, you must enable Multicast over Multicast (MOM). This allows OSPF to establish neighbor adjacencies between SVIs.


Configure OSPF protocol (GUI)

Configure OSPF protocol for dynamic routing between network devices using the GUI.

Procedure

1.

Choose Configuration > Routing Protocol > OSPF and click Add.

2.

In the Add Route page, select the router from the drop-down list.

3.

Enter the Process ID. It identifies the router’s OSPF routing process to other routers.

4.

Enter a Router ID.

5.

Enable the BFD to create a Bidirectional Forwarding Detection session between two systems. BFD provides a short-duration method for detecting failures in the forwarding path between two adjacent switches. This includes interfaces, data links, and forwarding planes. OSPF registers as a protocol with BFD and receives forwarding path detection failure messages from BFD. You can configure BFD support for OSPF globally on all interfaces, or selectively on specific interfaces. BFD timers are negotiated. The BFD peers begin sending BFD control packets to each other at the negotiated interval.

6.

Enable NSR on a router with redundant Route Processors (RPs) so that it maintains its Open Shortest Path First (OSPF) state and adjacencies during both planned and unplanned RP switchovers. The active RP transfers OSPF state information to the standby RP by checkpointing the data. After a switchover to the standby RP, OSPF uses the checkpointed information to continue operation without interruption.

Optionally, you can check the corresponding check box to enable VRF and select the VRF Name. If you have not configured the VRF, use the link to configure it on the Interface > VRF page.

7.

For advanced options, check the Advanced radio button and populate these fields:

IP Address: Enter the address of the destination network for this route.

Wildcard: Enter the subnet mask used on that network.

Area: The OSPF area number for that network. Each router in a particular OSPF area maintains a topological database for that area.

8.

Click Save & Apply to Device.


Configure basic OSPF parameters (CLI)

Enable OSPF routing and define key parameters for efficient dynamic route advertisement and network segmentation using commands.

Procedure

1.

Enter the global configuration mode.

Example:

Device# configure terminal
2.

Enable OSPF routing.

Example:

Device(config)# router ospf process-id

The process-id is an internally used identification parameter that is locally assigned and can be any positive integer. Each OSPF routing process has a unique value.

Note

The OSPF for Routed Access supports a maximum of 1000 dynamically learned routes.

3.

Define a network on which the OSPF runs an area ID for that interface.

Example:

Device(config-router)# network address wildcard-mask area area-id

You can use the wildcard-mask to define one or more interfaces to be associated with a specific OSPF area. The area-id can be a decimal value or an IP address.

4.

Enable Bidirectional Forwarding Detection (BFD) in all interfaces.

Example:

Device(config-router)# bfd all-interfaces
5.

Return to privileged EXEC mode.

Example:

Device(config-router)# end

Configure OSPF interfaces (CLI)

Configure router interfaces to participate in OSPF routing, enabling dynamic route exchange within OSPF areas on the network.

Procedure

1.

Enter the global configuration mode.

Example:

Device# configure terminal
2.

Specify interface to configure OSPF interfaces.

Example:

Device(config)# interface GigabitEthernet interface-number
3.

Configure IP address for the OSPF interface.

Example:

Device(config-if)# ip address ip-address mask-address
4.

Enable message digest for a specific interface.

Example:

Device(config-if)# ip ospf authentication message-digest
5.

Enable message digest key for the OSPF.

Example:

Device(config-if)# ip ospf authentication message-digest-key key-number md5 password
6.

Assign interface and its network to OSPF process and area.

Example:

Device(config-if)# ip ospf value area area-id
7.

Enable BFD in an interface.

Example:

Device(config-if)# ip ospf bfd
8.

Return to privileged EXEC mode.

Example:

Device(config-if)# end

Verify routing protocol details

To verify the OSPF details, use this command:

Device# show ip ospf 1
Routing Process "ospf 1" with ID 31.31.31.1
 Start time: 00:01:46.103, Time elapsed: 03:12:34.745
 Supports only single TOS(TOS0) routes
 Supports opaque LSA
 Supports Link-local Signaling (LLS)
 Supports area transit capability
 Supports NSSA (compatible with RFC 3101)
 Supports Database Exchange Summary List Optimization (RFC 5243)
 Event-log enabled, Maximum number of events: 1000, Mode: cyclic
 Router is not originating router-LSAs with maximum metric
 Initial SPF schedule delay 50 msecs
 Minimum hold time between two consecutive SPFs 200 msecs
 Maximum wait time between two consecutive SPFs 5000 msecs
 Incremental-SPF disabled
 Initial LSA throttle delay 50 msecs
 Minimum hold time for LSA throttle 200 msecs
 Maximum wait time for LSA throttle 5000 msecs
 Minimum LSA arrival 100 msecs
 LSA group pacing timer 240 secs
 Interface flood pacing timer 33 msecs
 Retransmission pacing timer 66 msecs
 EXCHANGE/LOADING adjacency limit: initial 300, process maximum 300
 Number of external LSA 0. Checksum Sum 0x000000
 Number of opaque AS LSA 0. Checksum Sum 0x000000
 Number of DCbitless external and opaque AS LSA 0
 Number of DoNotAge external and opaque AS LSA 0
 Number of areas in this router is 1. 1 normal 0 stub 0 nssa
 Number of areas transit capable is 0
 External flood list length 0
 IETF NSF helper support enabled
 Cisco NSF helper support enabled
 Reference bandwidth unit is 100 mbps
    Area 1
        Number of interfaces in this area is 3
	Area has no authentication
	SPF algorithm last executed 03:11:47.277 ago
	SPF algorithm executed 9 times
	Area ranges are
	Number of LSA 5. Checksum Sum 0x0212EE
	Number of opaque link LSA 0. Checksum Sum 0x000000
	Number of DCbitless LSA 0
	Number of indication LSA 0
	Number of DoNotAge LSA 0
	Flood list length 0

To verify the OSPF database details, use this command:

Device# show ip ospf 1 database
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Router Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum Link count
31.31.31.1      31.31.31.1      1470        0x8000000C 0x00289A 3         
50.50.50.1      50.50.50.1      1745        0x8000000A 0x001018 3         
51.51.51.1      51.51.51.1      1500        0x8000000A 0x008EFB 2         
		Net Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum
30.30.30.2      50.50.50.1      1745        0x80000006 0x00B793
31.31.31.2      51.51.51.1      1500        0x80000006 0x0093AE

To verify the IP route details, use this command:

Device# 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, m - OMP
       n - NAT, Ni - NAT inside, No - NAT outside, Nd - NAT DIA
       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
       H - NHRP, G - NHRP registered, g - NHRP registration summary
       o - ODR, P - periodic downloaded static route, l - LISP
       a - application route
       + - replicated route, % - next hop override, p - overrides from PfR
       & - replicated local route overrides by connected
Gateway of last resort is not set
      5.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        5.5.5.0/24 is directly connected, Vlan5
L        5.5.5.2/32 is directly connected, Vlan5
      6.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        6.6.6.0/24 is directly connected, Vlan6
L        6.6.6.2/32 is directly connected, Vlan6
      30.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        30.30.30.0/24 is directly connected, GigabitEthernet3
L        30.30.30.1/32 is directly connected, GigabitEthernet3
      31.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C        31.31.31.0/24 is directly connected, GigabitEthernet4
L        31.31.31.1/32 is directly connected, GigabitEthernet4
      32.0.0.0/24 is subnetted, 1 subnets
O        32.32.32.0 [110/2] via 30.30.30.2, 03:11:58, GigabitEthernet3
      50.0.0.0/32 is subnetted, 1 subnets
O        50.50.50.1 [110/2] via 30.30.30.2, 03:11:58, GigabitEthernet3
      51.0.0.0/32 is subnetted, 1 subnets
O        51.51.51.1 [110/2] via 31.31.31.2, 03:12:00, GigabitEthernet4

To verify the IP OSPF route list details, use this command:

Device# show ip ospf 1 route-list
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Base Topology (MTID 0)
    Area 1
    Intra-area Route List
*   31.31.31.0/24, Intra, cost 1, area 1, Connected
      via 31.31.31.1, GigabitEthernet4
*   30.30.30.0/24, Intra, cost 1, area 1, Connected
      via 30.30.30.1, GigabitEthernet3
*   6.6.6.0/24, Intra, cost 1, area 1, Connected
      via 6.6.6.2, Vlan6
*>  32.32.32.0/24, Intra, cost 2, area 1
      via 30.30.30.2, GigabitEthernet3
*>  50.50.50.1/32, Intra, cost 2, area 1
      via 30.30.30.2, GigabitEthernet3
*>  51.51.51.1/32, Intra, cost 2, area 1
      via 31.31.31.2, GigabitEthernet4
    First Hop Forwarding Gateway Tree
 31.31.31.1 on GigabitEthernet4, count 1
 31.31.31.2 on GigabitEthernet4, count 1
 30.30.30.1 on GigabitEthernet3, count 1
 30.30.30.2 on GigabitEthernet3, count 2
 6.6.6.2 on Vlan6, count 1

To verify the OSPF traffic details, use this command:

Device# show ip ospf 1 traffic
OSPF Router with ID (31.31.31.1) (Process ID 1)
OSPF queue statistics for process ID 1:
                   InputQ     UpdateQ    OutputQ
  Limit            0          200        0         
  Drops            0          0          0         
  Max delay [msec] 1          1          1         
  Max size         2          2          2         
    Invalid        0          0          0         
    Hello          0          0          0         
    DB des         0          0          1         
    LS req         1          1          1         
    LS upd         1          1          0         
    LS ack         0          0          0         
  Current size     0          0          0         
    Invalid        0          0          0         
    Hello          0          0          0         
    DB des         0          0          0         
    LS req         0          0          0         
    LS upd         0          0          0         
    LS ack         0          0          0         
Interface statistics:
.
.
.
    Interface GigabitEthernet4
Summary traffic statistics for process ID 1:
OSPF packets received/sent
  Type          Packets              Bytes
  RX Invalid    0                    0
  RX Hello      2435                 116880
  RX DB des     17                   584
  RX LS req     2                    96
  RX LS upd     24                   2360
  RX LS ack     24                   1436
  RX Total      2502                 121356
  TX Failed     0                    0
  TX Hello      3653                 506540
  TX DB des     6                    704
  TX LS req     2                    144
  TX LS upd     31                   4204
  TX LS ack     14                   1560
  TX Total      3706                 513152
OSPF header errors
  Length 0, Instance ID 0, Checksum 0, Auth Type 0,
  Version 0, Bad Source 0, No Virtual Link 0,
  Area Mismatch 0, No Sham Link 0, Self Originated 0,
  Duplicate ID 0, Hello 0, MTU Mismatch 0,
  Nbr Ignored 0, LLS 0, Unknown Neighbor 0,
  Authentication 0, TTL Check Fail 0, Adjacency Throttle 0,
  BFD 0, Test discard 0
OSPF LSA errors
  Type 0, Length 0, Data 0, Checksum 0

To verify the OSPF neighbor details, use this command:

Device# show ip ospf 1 neighbor
Neighbor ID     Pri   State           Dead Time   Address         Interface
51.51.51.1        1   FULL/DR         00:00:37    31.31.31.2      GigabitEthernet4
50.50.50.1        1   FULL/DR         00:00:39    30.30.30.2      GigabitEthernet3

To verify the OSPF neighbor summary, use this command:

Device#show ip ospf 1 neighbor summary
            OSPF Router with ID (31.31.31.1) (Process ID 1)
DOWN         0
ATTEMPT      0
INIT         0
2WAY         0
EXSTART      0
EXCHANGE     0
LOADING      0
FULL         2
Total count  2    (Undergoing NSF 0)

To verify the OSPF event details, use this command:


                Device# show ip ospf 1 events
            OSPF Router with ID (31.31.31.1) (Process ID 1)
1    Sep 21 21:49:12.406: Generate Changed Type-1 LSA, LSID 31.31.31.1, Seq# 8000000C, Age 0, Area 1
2    Sep 21 21:48:44.064: Rcv Unchanged Type-2 LSA, LSID 31.31.31.2, Adv-Rtr 51.51.51.1, Seq# 80000006, Age 1, Area 1
3    Sep 21 21:48:44.064: Rcv Unchanged Type-1 LSA, LSID 51.51.51.1, Adv-Rtr 51.51.51.1, Seq# 8000000A, Age 1, Area 1
4    Sep 21 21:44:38.726: Rcv Unchanged Type-2 LSA, LSID 30.30.30.2, Adv-Rtr 50.50.50.1, Seq# 80000006, Age 1, Area 1
5    Sep 21 21:44:38.726: Rcv Unchanged Type-1 LSA, LSID 50.50.50.1, Adv-Rtr 50.50.50.1, Seq# 8000000A, Age 1, Area 1
.
.
.
30   Sep 21 19:01:45.594: End of SPF, Topo Base, SPF time 1ms, next wait-interval 800ms
.
.
.
74   
                
                Sep 21 19:01:44.676: Generic:  ospf_external_route_sync  0x1
                
                75   Sep 21 19:01:44.676: Generic:  ospf_external_route_sync  0x1
76   Sep 21 19:01:44.676: Generic:  ospf_external_route_sync  0x0
77   Sep 21 19:01:44.676: Generic:  ospf_external_route_sync  0x0
78   Sep 21 19:01:44.676: Starting External processing, Topo Base in area 1
79   Sep 21 19:01:44.676: Starting External processing, Topo Base
80   
                
                Sep 21 19:01:44.676: Generic:  ospf_inter_route_sync  0x1
                
81   Sep 21 19:01:44.676: Generic:  ospf_inter_route_sync  0x1
82   Sep 21 19:01:44.676: Starting summary processing, Topo Base, Area 1
83   
                
                Sep 21 19:01:44.676: Generic:  post_spf_intra  0x0
84   Sep 21 19:01:44.676: Generic:  ospf_intra_route_sync  0x1
                
.
.
.
            

To verify the OSPF details in the database summary, use this command:

Device# show ip ospf 1 database database-summary
OSPF Router with ID (31.31.31.1) (Process ID 1)
Area 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0       
  Network       2        0        0       
  Summary Net   0        0        0       
  Summary ASBR  0        0        0       
  Type-7 Ext    0        0        0       
    Prefixes redistributed in Type-7  0
  Opaque Link   0        0        0       
  Opaque Area   0        0        0       
  Subtotal      5        0        0   
Process 1 database summary
  LSA Type      Count    Delete   Maxage
  Router        3        0        0       
  Network       2        0        0       
  Summary Net   0        0        0       
  Summary ASBR  0        0        0       
  Type-7 Ext    0        0        0       
  Opaque Link   0        0        0       
  Opaque Area   0        0        0       
  Type-5 Ext    0        0        0       
      Prefixes redistributed in Type-5  0
  Opaque AS     0        0        0       
  Total         5        0        0       
  Non-self      4      
 

To verify the OSPF details in the internal database, use this command:

Device# show ip ospf 1 database internal
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Stub Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum Mask
6.6.6.255       31.31.31.1      11545       0x0        0x006611 /24
30.30.30.255    31.31.31.1      11546       0x0        0x00032C /24
31.31.31.255    31.31.31.1      11548       0x0        0x00DE4D /24
32.32.32.255    50.50.50.1      11545       0x0        0x00F0FE /24
50.50.50.1      50.50.50.1      11545       0x0        0x005C5C /32
51.51.51.1      51.51.51.1      11547       0x0        0x002092 /32
		Router Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum Link count
31.31.31.1      31.31.31.1      1498        0x8000000C 0x00289A 3         
50.50.50.1      50.50.50.1      1772        0x8000000A 0x001018 3         
51.51.51.1      51.51.51.1      1527        0x8000000A 0x008EFB 2         
		Net Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum
30.30.30.2      50.50.50.1      1772        0x80000006 0x00B793
31.31.31.2      51.51.51.1      1527        0x80000006 0x0093AE

To verify the OSPF details in the database network, use this command:

Device# show ip ospf 1 database network
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Net Link States (Area 1)
  LS age: 1772
  Options: (No TOS-capability, DC)
  LS Type: Network Links
  Link State ID: 30.30.30.2 (address of Designated Router)
  Advertising Router: 50.50.50.1
  LS Seq Number: 80000006
  Checksum: 0xB793
  Length: 32
  Network Mask: /24
	Attached Router: 50.50.50.1
	Attached Router: 31.31.31.1
  LS age: 1527
  Options: (No TOS-capability, DC)
  LS Type: Network Links
  Link State ID: 31.31.31.2 (address of Designated Router)
  Advertising Router: 51.51.51.1
  LS Seq Number: 80000006
  Checksum: 0x93AE
  Length: 32
  Network Mask: /24
	Attached Router: 51.51.51.1
	Attached Router: 31.31.31.1

To verify the OSPF details in the database router, use this command:

Device# show ip ospf 1 database router
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Router Link States (Area 1)
  LS age: 1498
  Options: (No TOS-capability, DC)
  LS Type: Router Links
  Link State ID: 31.31.31.1
  Advertising Router: 31.31.31.1
  LS Seq Number: 8000000C
  Checksum: 0x289A
  Length: 60
  Number of Links: 3
    Link connected to: a Transit Network
     (Link ID) Designated Router address: 31.31.31.2
     (Link Data) Router Interface address: 31.31.31.1
      Number of MTID metrics: 0
       TOS 0 Metrics: 1
    Link connected to: a Transit Network
     (Link ID) Designated Router address: 30.30.30.2
     (Link Data) Router Interface address: 30.30.30.1
      Number of MTID metrics: 0
       TOS 0 Metrics: 1
    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 6.6.6.0
     (Link Data) Network Mask: 255.255.255.0
      Number of MTID metrics: 0
       TOS 0 Metrics: 1
.
.
.

To verify the OSPF details in the database topology, use this command:

Device# show ip ospf 1 database topology
OSPF Router with ID (31.31.31.1) (Process ID 1)
		Base Topology (MTID 0)
		Router Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum Link count
31.31.31.1      31.31.31.1      1498        0x8000000C 0x00289A 3         
50.50.50.1      50.50.50.1      1772        0x8000000A 0x001018 3         
51.51.51.1      51.51.51.1      1527        0x8000000A 0x008EFB 2         
		Net Link States (Area 1)
Link ID         ADV Router      Age         Seq#       Checksum
30.30.30.2      50.50.50.1      1772        0x80000006 0x00B793
31.31.31.2      51.51.51.1      1527        0x80000006 0x0093AE
vWLC_TB1#
vWLC_TB1#show ip ospf 1 request-list
            OSPF Router with ID (31.31.31.1) (Process ID 1)
 Neighbor 51.51.51.1, interface GigabitEthernet4 address 31.31.31.2
 Request list size 0, maximum list size 1
 Neighbor 50.50.50.1, interface GigabitEthernet3 address 30.30.30.2
 Request list size 0, maximum list size 1
vWLC_TB1#
vWLC_TB1#show ip ospf flood-list  
            OSPF Router with ID (31.31.31.1) (Process ID 1)
 Interface GigabitEthernet4, Queue length 0
 Interface GigabitEthernet3, Queue length 0
 Interface Vlan6, Queue length 0

To verify the OSPF request details, use this command:

Device# show ip ospf request-list Gi3 50.50.50.1
OSPF Router with ID (31.31.31.1) (Process ID 1)
 Neighbor 50.50.50.1, interface GigabitEthernet3 address 30.30.30.2
 Request list size 0, maximum list size 1

To verify the OSPF interface details, use this command:

Device# show ip ospf interface  
GigabitEthernet4 is up, line protocol is up 
  Internet Address 31.31.31.1/24, Interface ID 10, Area 1
  Attached via Network Statement
  Process ID 1, Router ID 31.31.31.1, 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) 51.51.51.1, Interface address 31.31.31.2
  Backup Designated router (ID) 31.31.31.1, Interface address 31.31.31.1
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:03
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Can be protected by per-prefix Loop-Free FastReroute
  Can be used for per-prefix Loop-Free FastReroute repair paths
  Not Protected by per-prefix TI-LFA
  Index 1/3/3, 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 51.51.51.1  (Designated Router)
  Suppress hello for 0 neighbor(s)
  Cryptographic authentication enabled
    Youngest key id is 1
GigabitEthernet3 is up, line protocol is up 
  Internet Address 30.30.30.1/24, Interface ID 9, Area 1
  Attached via Network Statement
  Process ID 1, Router ID 31.31.31.1, 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) 50.50.50.1, Interface address 30.30.30.2
  Backup Designated router (ID) 31.31.31.1, Interface address 30.30.30.1
  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
  Can be protected by per-prefix Loop-Free FastReroute
  Can be used for per-prefix Loop-Free FastReroute repair paths
  Not Protected by per-prefix TI-LFA
  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 50.50.50.1  (Designated Router)
  Suppress hello for 0 neighbor(s)
  Cryptographic authentication enabled
    Youngest key id is 1
Vlan6 is up, line protocol is up 
  Internet Address 6.6.6.2/24, Interface ID 16, Area 1
  Attached via Interface Enable
  Process ID 1, Router ID 31.31.31.1, Network Type BROADCAST, Cost: 1
  Topology-MTID    Cost    Disabled    Shutdown      Topology Name
        0           1         no          no            Base
  Enabled by interface config, including secondary ip addresses
  Transmit Delay is 1 sec, State DR, Priority 1
  Designated Router (ID) 31.31.31.1, Interface address 6.6.6.2
  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 00:00:01
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Can be protected by per-prefix Loop-Free FastReroute
  Can be used for per-prefix Loop-Free FastReroute repair paths
  Not Protected by per-prefix TI-LFA
  Index 1/1/1, flood queue length 0
  Next 0x0(0)/0x0(0)/0x0(0)
  Last flood scan length is 0, maximum is 0
  Last flood scan time is 0 msec, maximum is 0 msec
  Neighbor Count is 0, Adjacent neighbor count is 0 
  Suppress hello for 0 neighbor(s)
  Cryptographic authentication enabled
    Youngest key id is 1