Definition of ABR in OSPF on S series switches

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Question: What is the definition of ABR? Is a device with more than two areas configured an ABR?

Answer: According to RFC 2328, an OSPF backbone area contains the ABRs of all areas. That is, an ABR must belong to a backbone area. If Area 2 and Area 3 are configured on a device with no interface in a backbone area, the device is not an ABR.
If two or more areas are configured on an S series switch supporting OSPF and one of these areas is a backbone area, the switch is an ABR. Not all these areas must have interfaces in the Up state.

Other related questions:
OSPF cost of S series switches
The ospf cost command can be executed on an S series switch that supports OSPF to configure the cost required for running the OSPF protocol on an interface. Application scenario: The interface cost can be automatically calculated by OSPF based on the interface bandwidth or manually configured by using the ospf cost command. If the costs and destination IP addresses of multiple routes discovered by one routing protocol are the same, load balancing can be implemented among the routes. Modify interface costs to implement load balancing as required. Configuration impact: If no interface cost is configured by using the ospf cost command, OSPF automatically calculates the interface cost based on the interface bandwidth. The calculation formula is as follows: Cost of the interface = Bandwidth reference value/Interface bandwidth. The integer of the calculated result is the cost of the interface. If the calculated result is smaller than 1, the cost value is 1. Changing the bandwidth reference value can change the cost of an interface. By default, the bandwidth reference value is 100 Mbit/s. Therefore, the default cost value of an Ethernet (100 Mbit/s) interface is 1 (100,000,000/the interface bandwidth). Example: Set the cost required by VLANIF 100 for running OSPF to 65. [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] ospf cost 65 Set the cost required by GE0/0/1 for running OSPF to 65. [HUAWEI] interface gigabitethernet 0/0/1 [HUAWEI-GigabitEthernet0/0/1] undo portswitch [HUAWEI-GigabitEthernet0/0/1] ospf cost 65 Note: The cost calculated by OSPF is the cost of the route to the outbound interface of the destination network.

Whether S series switches support OSPF
For details on whether S series switches in V200R008 and earlier versions support or do not support OSPF, see the following: �?S7700/S9700/S12700: Support �?S9300: Support �?S6720EI: Support �?S6700EI: Support �?S5720HI: Support �?S5710HI: Support �?S5700HI: Support �?S5720EI: Support �?S5710EI: Support �?S5700EI: Support �?S5720SI/S5720S-SI: Support �?S5700SI: Not support �?S5710LI: Not support �?S5700LI: Not support �?S5700S-LI: Not support �?S3700HI: Support �?S3700EI: Support �?S3700SI: Not support �?S2750EI: Not support �?S2720EI: Not support �?S2700EI: Not support �?S2710SI: Not support �?S2700SI: Not support �?S1720: Not support For details on whether S series switches in V200R008 and earlier versions support or do not support OSPFv3, see the following: �?S7700/S9700/S12700: Support �?S9300: Support �?S6720EI: Support �?S6700EI: Support �?S5720HI: Support �?S5710HI: Support �?S5700HI: Support �?S5720EI: Support �?S5710EI: Support �?S5700EI: Support �?S5720SI/S5720S-SI: Support �?S5700SI: Not support �?S5710LI: Not support �?S5700LI: Not support �?S5700S-LI: Not support �?S3700HI: Support �?S3700EI: Support �?S3700SI: Not support �?S2750EI: Not support �?S2720EI: Not support �?S2700EI: Not support �?S2710SI: Not support �?S2700SI: Not support �?S1720: Not support

Configure the priority of an OSPF route on an S series switch
The routing protocols may share and select the routing information because a switch may run multiple dynamic routing protocols simultaneously. In this case, a priority should be set for each routing protocol. When different protocols find multiple routes to the same destination, the route discovered by the protocol with a higher priority is preferred. On an S series switch, you can run the preference command in the OSPF process view to configure the OSPF priority. Perform the following operations: 1. Run the ospf [ process-id ] command in the system view to enter the OSPF process view. 2. Run the preference [ ase ] { preference | route-policy route-policy-name } * command to configure the OSPF priority. The parameters are described as follows: ase: indicates the priority of the AS-External route. preference: indicates the OSPF route priority. A smaller value indicates a higher priority. route-policy route-policy-name: indicates the priority for specified routes in the routing policy. The default OSPF priority value is 10. When an ASE is specified, the default OSPF priority is 150. For example, set the priority of routes in OSPF process 100 to 150 as follows: [HUAWEI] ospf 100 [HUAWEI-ospf-100] preference 150

Locate an OSPF fault on an S series switch
You can run the debugging ospf event command on S series switches supporting OSPF to locate most faults. If an OSPF fault cannot be located using this command, run the debugging ospf packet command to enable OSPF packet debugging and check whether OSPF packets are sent and received normally according to debugging information. Note: The debugging commands are used for fault location. Exercise caution when using the commands.

Configure OSPF neighbor authentication on an S series switch
OSPF authentication of S series switches includes area authentication and interface authentication. 1. Area authentication Run the authentication-mode command in an OSPF area view to set the authentication mode and password for the OSPF area. For example: [HUAWEI] ospf 100 [HUAWEI-ospf-100] area 0 [HUAWEI-ospf-100-area-0.0.0.0] authentication-mode simple cipher huawei To configure MD5 authentication, run the following command: [HUAWEI-ospf-100-area-0.0.0.0] authentication-mode md5 1 cipher huawei 2. Interface authentication The interface authentication mode is used among neighbor switches to set the authentication mode and password. Its priority is higher than that of the area authentication mode. Run the ospf authentication-mode command in the interface view to set the authentication mode and password for adjacent switches. For example: [HUAWEI] interface vlanif 100 [HUAWEI-Vlanif100] ospf authentication-mode simple cipher huawei To configure MD5 authentication, run the following command: [HUAWEI-Vlanif100]ospf authentication-mode md5 1 cipher huawei Note: When configuring area authentication or interface authentication, all switches involved must have the same authentication mode and password. If not, the switches may fail to set up an OSPF neighbor relationship.

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