1. Huawei HedEx Documentation (Official Vendor Documentation): In the HCIP-Datacom-Core Technology V1.0 Training Material
the section on BGP route attributes explicitly states this behavior.
Reference: Huawei
HCIP-Datacom-Core Technology V1.0 Training Material
"BGP Path Attributes" section.
Content: "The origin attribute has three values: IGP
EGP
and Incomplete... Incomplete: A route is imported using the import-route command. This type of route has the lowest priority." This directly confirms that the import-route command sets the origin to Incomplete.
2. Huawei HedEx Documentation (Official Vendor Documentation): The command reference for Huawei's VRP operating system details the behavior of BGP commands.
Reference: Huawei VRP V800R012C10 BGP Command Reference
"import-route" command description.
Content: The documentation on BGP route import mechanisms clarifies that when routes are redistributed from an IGP or static routes into BGP
their origin is marked as Incomplete (?).
3. Internet Engineering Task Force (IETF) RFC 4271: This is the foundational standard for BGP-4 and defines the ORIGIN attribute.
Reference: IETF RFC 4271
"A Border Gateway Protocol 4 (BGP-4)"
Section 5.1.1 "ORIGIN".
Content: The RFC defines the value 2 for the origin attribute as INCOMPLETE
specifying it is for "Network Layer Reachability Information learned by some other means." Redistribution
as performed by the import-route command
falls directly into the category of "some other means."