OSPF Area
What is OSPF Area?
An Open Shortest Path First (OSPF) area is divided from an autonomous system based on the OSPF protocol. This simplifies the hierarchical management of vRouters.
Concepts
- OSPF protocol: OSPF is a link-state routing protocol that is widely used in data center networks and campus networks.
- Area ID: An area ID is expressed in dotted decimal format (similar to an IPv4
address) to uniquely identify an OSPF area.
- Area 0 (whose area ID is 0.0.0.0) is a backbone area which combines a set of independent areas into a single domain.
- Area type: The Cloud supports the following two area types:
- Standard area: This area supports all types of LSAs.
- Stub area: This area does not support LSA 4 or LSA 5.
- OSPF area authentication: The Cloud supports the following three authentication
methods:
- None: Packets are received without identity authentication.
- Plaintext: Identity authentication is implemented by using the password contained in the received packets.
- MD5: Identity authentication is implemented by using the key ID and password MD5 hash that are contained in the received packets.
- Neighbor: OSPF neighbors are dynamically discovered by sending Hello packets out
each OSPF-enabled interface on a router.
- Depending on the complexity of the network topology and the settings of the OSPF timer, it may take several seconds (less than 60 seconds) from the start of OSPF to the establishment of the neighbor relationship.
- Router ID: Each OSPF router uses a router ID as its unique identifier.
- Make sure that each OSPF router has a router ID on your network before you can use the OSPF protocol properly.
- By default, the system uses the management network interface address of the VPC vRouter as the router ID.
- Generally, you can manually specify a router ID for a VPC vRouter. We recommended that you use a stable interface IP address.
- The router ID of VPC vRouters in an HA group cannot be modified.
Advantages
Compared with static routing, dynamic routing supports automatic
topology changes and recalculates routes without manual intervention, which is
applicable to large-scale network environments. Compared with other routing
protocols, OSPF has the following advantages:
- Unlimited number of routing hops.
- Updates routing and network changes by using multicast.
- Faster route convergence.
- Uses costs as a measurement.
- Avoids loops by using the SPF algorithm.
Create an OSPF Area
On the main menu of ZStack Cloud, choose . On the OSPF Area page, click Create OSPF Area. Then, the Create OSPF Area page is displayed.
On the displayed page, set the following parameters:
- Area ID: Set an area ID in dotted decimal notation that identifies an OSPF area. The area ID is in similar format as that of IPv4 address.
- Type: Select an OSPF area type. Valid values: Standard
and Stub.
- Standard: Standard areas support all types of LSAs.
- Stub: Stub areas do not support Type 4 and Type 5 LSAs.
- Authentication Method: The authentication method used
when you select VPC vRouters in an OSPF area to establish neighbors. Valid
values: None, Plaintext, and MD5.
- None: Packets are received without identity authentication.
- Plaintext: Identity authentication is implemented by using the password contained in the received packets.
- MD5: Identity authentication is implemented by using the key ID
and password MD5 hash that are contained in the received
packets.
Note: The Key ID must be 1 to 255 integer.
- Routing Configuration: Optional. Set routing
configurations. If you set this parameter, you need to:
- Select a VPC vRouter to add to the OSPF area.
- Select a network associated with the VPC vRouter to add to the OSPF area.
Note: You can add a VPC vRouter to multiple OSPF areas, but you can add a
VPC network or public network associated with the VPC vRouter to only one
OSPF area.
