CCNP Service Provider 350-501 Exam Dumps

The neighbor relationship is down because R2 is operating as a Level 1 router and the two routers are in different areas. In the IS-IS (Intermediate System to Intermediate System) protocol, Level 1 routers exchange routing information with other Level 1 routers in the same area, while Level 2 routers exchange information between areas. Since R1 is configured as a level-2 router and R2 as a level-1 router, they cannot form a neighbor relationship if they are not in the same area. References: Implementing and Operating Cisco Service Provider Network Core Technologies source documents or study guide

Cisco MPLS TE (Traffic Engineering) tunnels provide a way to optimize traffic routing within an MPLS network. However, there are certain constraints to be aware of:

• QoS-aware tunneling: Unfortunately, Cisco MPLS TE tunnels do not inherently support Quality of Service (QoS) awareness. This means that the tunnels themselves do not directly consider QoS parameters when making routing decisions. QoS policies must be applied separately at the network level, and the TE tunnels do not inherently take QoS into account during path selection.
• Tunnels spanning multiple OSPF areas: Contrary to option A, Cisco MPLS TE tunnels can indeed span multiple OSPF areas. The use of OSPF areas does not inherently restrict the creation of MPLS TE tunnels across area boundaries.
• ISIS metrics: Option B is incorrect. When using ISIS (Intermediate System to Intermediate System) as the Interior Gateway Protocol (IGP), newer-style metrics (such as wide metrics) are supported. Older-style metrics are not the only option.
• Tunnels over IP unnumbered links: Option C is also incorrect. Cisco MPLS TE tunnels can be configured over IP unnumbered links, allowing efficient use of IP addresses.

In summary, the primary constraint is the lack of built-in QoS awareness within MPLS TE tunnels.

References:

• Implementing an MPLS VPN over TE Tunnels - Cisco Support
• Configuring Basic MPLS TE - Cisco NX-OS

In the given scenario, the goal is to restrict users on the network between R1 and R2 from accessing the external network through R5, while still allowing them access to all resources within the administrative domain. The correct approach is to configure an Access Control List (ACL) that permits traffic to all internal networks and denies traffic to any external address. This ACL should be applied to the R2 interface that connects to R1 in the ingress direction. By doing so, traffic originating from users between R1 and R2 destined for external networks will be blocked, while internal traffic will be allowed.

References: This explanation is derived from the Implementing and Operating Cisco Service Provider Network Core Technologies (SPCOR) study materials, which cover the configuration and application of ACLs in a service provider network environment.

YANG (Yet Another Next Generation) is a data modeling language used primarily for the configuration and state data of network elements. It is closely associated with the NETCONF (Network Configuration Protocol) for which it models configuration data. YANG provides schemas that define how data is structured and transported by NETCONF operations. It also shapes the state data of network elements, allowing for a standardized format for representing the operational state of devices. References: YANG is defined in RFCs such as RFC 6020 and RFC 7950, which outline its role in NETCONF operations and its capabilities in modeling both configuration and state data.