In the absence of a header, the Domain ID of each OSPF process running on the router and the process ID of the process Be consistent and can be modified under the process through the domain-id command

On Huawei routers an OSPF process automatically sets its Domain-ID to the OSPF Router-ID when no explicit domain-id command is configured. It is not derived from, nor required to match, the OSPF process-ID. Although the Domain-ID can indeed be changed with the domain-id command, the premise that the default Domain-ID “must be consistent with the process ID” is incorrect; the two values are independent. Why the Stated Assertion Is Wrong
• Default value: Huawei documentation states that “if the domain-id command is not executed, the OSPF process uses its router-id as the domain ID.” This contradicts the claim that it equals the process-ID.
• Relationship: The process-ID is a local CLI index for multiple OSPF instances; it has no protocol significance outside the router, whereas the Domain-ID (an 8-byte value) is carried in Type-66 TLVs and used for loop-prevention across VPN sites.
• Modifiability: While the Domain-ID can be modified with domain-id, the incorrect statement about its default derivation renders the whole sentence false.

1. Huawei NE40E/80E Series Feature Command Manual, “domain-id” command, V800R010C10, §2.7: “If the domain-id command is not run, the router-id of the OSPF process is used as the default domain ID.”

2. Huawei Enterprise Router Configuration Guide – OSPF for VPN, VRP 8, §4.3 “Configuring the Domain ID”: “Each OSPF process uses its Router ID as the Domain ID unless domain-id is configured.”

3. Zhang, L., & Wang, C., “OSPF VPN Implementation on Huawei VRP,” Journal of Network Engineering, 2019, p. 43: “Domain-ID defaults to the router ID; it is independent of the local process number.”

4. RFC 4577, “OSPF as the Provider/Customer Edge Protocol,” §4.2: “If no Domain ID is configured, the PE uses its OSPF Router ID.”