Cisco 350-501 - Implementing and Operating Cisco Service Provider Network Core Technologies (350-501 SPCOR)

To establish LDP sessions between the PE and P routers, you need to enable communication over TCP port 646 for T-LDP hello messages.

T-LDP (Targeted LDP) uses TCP port 646 for session establishment.

Example configuration:

interface GigabitEthernet0/0

mpls ldp discovery targeted-hello accept

References:

Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0 course material.

In this scenario, when edge routers at different regional sites are connected over a global carrier backbone, MP-eBGP must be run between routers to exchange customer VPNv4 routes. This is essential for enabling communication between customer sites located in different regions while utilizing a global carrier backbone service. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

In the given architecture, if each area is running its own Interior Gateway Protocol (IGP), Border Gateway Protocol (BGP) must be used to provide an end-to-end Multiprotocol Label Switching (MPLS) Label Switched Path (LSP). This ensures that data packets can traverse through the different IGP areas seamlessly, maintaining connectivity across the entire network.

In the context of VPLS (Virtual Private LAN Service) configuration, the engineer should perform additional configurations to enable the virtual switch instance. The correct answer is Option A, which likely involves configuring interface VLAN and associating it with xconnect vfi to establish end-to-end LAN connectivity between customer’s remote offices. This is essential for enabling VPLS, which allows geographically dispersed sites to be connected over a service provider’s network as if they were on the same local area network.

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) - Cisco SPCOR Training & Certification

 In this scenario, the network engineer is integrating several recently acquired networks into a more scalable common Unified MPLS architecture. The architecture will support end-to-end VPNv4 and VPNv6 services. The requirements include using IS-IS in Area 0 for the core layer and OSPF in Area 0 for the aggregation layers. LDP is used to distribute label bindings within each IGP domain.

To achieve this, the engineer must configure the ABR (Area Border Router) in each IGP domain to preserve next-hop information on all VPNv4 and VPNv6 prefixes advertised by the PE (Provider Edge) routers. This ensures that the correct next-hop information is maintained throughout the network, allowing end-to-end connectivity for MPLS LSPs (Label Switched Paths).

References: Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) v1.0 course material

 Router R1 is configured as a stub area with the “no-summary” option, which means it will not receive summary LSAs (Type 3) from the Area Border Router (ABR). It will only have Type 1 (Router LSAs) and Type 2 (Network LSAs) in its OSPF database for the area it belongs to. Router R2 is configured as an NSSA (Not So Stubby Area), which allows it to import AS external routes as Type-7 LSAs. These Type-7 LSAs can then be converted to Type-5 LSAs by the ABR when propagated into other areas. Therefore, R2 has Types 1, 2, and 7 LSAs in its OSPF database.

References: For more detailed information, please refer to the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) course materials, specifically the sections covering OSPF area types and LSA types.