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

Application, table Description automatically generated with medium confidence

Option B: Internet routing through global routing on a PE router means that the PE router performs global routing for internet traffic. This allows the PE router to handle both L3VPN traffic and internet traffic.

Option D: Leaking internet routes from the global table into the L3VPN VRF allows the L3VPN customers to access the internet via the same MPLS backbone. The PE router imports internet routes into the L3VPN VRF, enabling internet access for VPN customers.

 MPLS TE tunnels are designed to optimize the flow of network traffic by mapping it onto specific paths based on resource requirements. Two key characteristics of MPLS TE tunnels are:

RSVP for Bandwidth Reservation: MPLS TE tunnels use the Resource Reservation Protocol (RSVP) to reserve the necessary bandwidth for the tunnel, ensuring that the required resources are available for the data that will flow through it12.

Unidirectional Flow: These tunnels are unidirectional, meaning they are established from a source to a destination and do not inherently support traffic in the reverse direction. This is because each MPLS TE tunnel is associated with a label-switched path (LSP) that is specifically set up for traffic flowing in one direction

The Adjacency-SID sub-TLV extension is advertised within TLV-22 (Extended IS Reachability) to label a specific link in a segment routing domain. This allows for the identification and utilization of specific paths or links within the network, facilitating more efficient routing and traffic management. References := Implementing and Operating Cisco Service Provider Network Core Technologies

The Internet gateway router being connected as a PE router to the MPLS backbone is a design attribute that can be used to provide Internet access to a major customer through a separate dedicated VPN. This setup allows for efficient routing and separation of traffic, ensuring security and performance.

The difference between SNMP (Simple Network Management Protocol) and model-driven telemetry lies in their data delivery mechanisms. Telemetry allows for modeled network data to be pushed to network administrators on an as-needed basis, providing real-time insights into network performance and health. On the other hand, SNMP typically relies on polling mechanisms where network administrators request data at specific intervals. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

The issue of no LDP neighbor existing for 1.1.1.1 between two directly connected routers could be due to R2 not receiving any hellos from R1. In the context of LDP (Label Distribution Protocol), hellos are used for the discovery of LDP peers. They are sent periodically on each interface that LDP is enabled on to discover and maintain LDP sessions with neighbors. If R2 is not seeing any hellos from R1, it means there’s a failure in the initial step of establishing an LDP session, hence no neighbor relationship is formed.

References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide can provide more insights into the workings and troubleshooting steps for LDP protocol.