The domain-id command sets the ID for an OSPF domain.
The undo domain-id command restores the default setting.
By default, the domain ID is null.
Parameter | Description | Value |
---|---|---|
null |
Indicates that the OSPF domain ID is null. |
- |
domain-idvalue |
Specifies the ID of an OSPF domain as an integer. |
It is an integer, the value ranges from 0 to 4294967295. The value is converted to dotted decimal notation (with 256 as a carry) when the ID is displayed. |
domain-idvalue_ipv4 |
Specifies the ID of an OSPF domain as an IP address. |
It is in dotted decimal notation, it is displayed as entered. |
type |
Specifies the domain ID type. |
- |
0005 |
Specifies the type 0x0005. |
- |
0105 |
Specifies the type 0x0105. |
- |
0205 |
Specifies the type 0x0205. |
- |
8005 |
Specifies the type 0x8005. |
- |
value domainTypeValue |
Specifies the value of the OSPF domain ID. |
The value is a hexadecimal number ranging from 0 to FFFF, and the default value is 0. |
secondary |
Indicates the ID of a secondary domain. |
- |
Usage Scenario
Domain IDs are used to identify domains.
If the local OSPF area and an OSPF area of a remote VPN attempt to exchange Type 3 LSAs, the two areas must be in the same OSPF domain. You can run the domain-id command to configure the same domain ID for the two OSPF areas. The routes that are imported from a PE Router are advertised using External-LSAs. The routes destined for different nodes in the same OSPF domain are advertised based on Type-3 LSAs. This requires that the nodes in the same OSPF domain be configured with the same domain ID. OSPF direct routes to a PE do not carry the domain ID, whereas BGP direct routes to a PE do. If the undo domain-id command with no parameter specified is executed, the primary domain ID will be deleted.Configuration Impact
Before sending routes to a remote CE Router, a PE Router sends Type-3 LSAs or Type-5 LSAs to the CE based on domain ID. If local domain IDs are the same as or compatible with remote domain IDs in BGP routes, the PE advertises Type 3 routes. If local domain IDs are different from or incompatible with remote domain IDs in BGP routes, the PE advertises Type 5 routes.
Precautions