When implementing a BGP policy on an Alcatel-Lucent 7750 SR, which of the following types of address space would a typical address plan need to cover?

A comprehensive BGP address plan for a service provider network, such as one using the Nokia 7750 SR, must account for all types of IP address space to implement robust and secure routing policies. The plan is used to create filters and policies that control route advertisement and acceptance. This includes the provider's own public CIDR blocks (RIR assigned), prefixes belonging to external customers, and all internal infrastructure addresses (loopbacks, internal and external point-to-point links). Properly categorizing all these address types is fundamental to preventing the leakage of internal routes and ensuring only authorized prefixes are announced to the internet.

A. RIR assigned CIDR space: This is a critical component, but it is not the only one. A plan covering only this space would fail to manage customer routes or filter internal infrastructure addresses.
B. External client address space: This is necessary for providers offering transit, but it omits the provider's own address space and the crucial infrastructure space that must be filtered.
C. Loopback or link addresses: While essential to identify for filtering from external advertisements, this category alone is insufficient for a complete BGP policy which must also define what to advertise.
D. External link addresses: Similar to internal links, these must be identified and typically filtered, but this represents only a small fraction of the addresses a complete plan must cover.

1. Nokia 7750 SR OS Router Configuration Guide, Release 22.10.R1, Part No: 3HE 18151 AAAC TQZZA, Section: BGP. The guide details the configuration of BGP policies using policy statements that reference prefix lists. Real-world policy examples implicitly require the operator to define prefix lists for different address types, including provider aggregates, customer prefixes, and infrastructure addresses (loopbacks/links), to control route propagation effectively. For instance, an export policy to the internet would permit provider and customer prefixes but explicitly deny infrastructure prefixes. This demonstrates the need for a plan covering all listed address types.

2. Nokia Interior Routing Protocols: SRC-PE Student Guide, Module 3: Routing Policy. This courseware explains the fundamentals of building routing policies on the 7750 SR. It emphasizes the creation of prefix lists to match specific categories of routes, such as infrastructure addresses (loopbacks, link nets) and user/customer prefixes, as a best practice for filtering and controlling advertisements in both IGPs and BGP. This confirms that a typical address plan must distinguish between these various address spaces.