Pass the Nokia Network Routing Specialist II (NRS II) 4A0-114 Questions and answers with ExamsMirror

n a traditional (non-EVPN) VPRN service configured using MP-BGP and LDP transport tunnels, the service label has the following characteristics:

A. False: The service label is not advertised using LDP; LDP is used for establishing the transport tunnels.

B. False: The service label is not prepended to the customer IPv4 prefixes.

C. False: The service label does not need to be manually configured for the VPRN on each PE router.

The correct statement is:

D. True: The service label is carried in an MP-BGP VPN-IPv4 route update. MP-BGP carries the VPN-IPv4 prefixes along with the associated service labels.

ReferencesNokia Border Gateway Protocol Fundamentals, Chapter on BGP/MPLS VPNs and VPRN Services.

The outer label in a multi-region VPRN (Virtual Private Routed Network) service is typically pushed by an ingress router, such as Core1.

The second label, often a transport label, is used for forwarding within the MPLS network and is pushed by routers like RBR1.

The service label is associated with the VPRN service and pushed by the ingress PE router, such as PE1.

The outer label is indeed popped by the penultimate router in an MPLS LSP (Label Switched Path), which would be Core2.

Therefore, the statement "The second label is a BGP label pushed by router RBR1." is FALSE.

References:

Nokia Border Gateway Protocol Fundamentals documentation, Section 7.4 on MPLS label operations.

Route reflectors (RR) are used in BGP to reduce the number of iBGP sessions required within an Autonomous System (AS). Here are key points about route reflectors:

B. True: A route reflector can have both iBGP and eBGP clients, allowing it to propagate routes between internal and external peers.

C. True: A route reflector disables the iBGP split-horizon rule for its clients, allowing it to propagate routes received from one iBGP client to other iBGP clients.

D. True: Route reflectors reduce the number of iBGP sessions required in an AS by allowing clients to form iBGP sessions only with the route reflector instead of with every other iBGP peer.

The false statement is:

A. False: A full iBGP mesh is not required among route reflectors themselves. Instead, route reflectors can form a partial mesh or hierarchical structure to propagate routes efficiently.

ReferencesNokia Border Gateway Protocol Fundamentals, Chapter on Route Reflectors.

BGP Shortcuts Concept: BGP shortcuts leverage MPLS tunnels to carry transit traffic efficiently across the network, reducing the need for full-mesh iBGP peering.

Statement Analysis:

Option A: Correct. MPLS tunnels are indeed used to carry transit traffic across the network.

Option B: Correct. A full mesh of iBGP peering sessions is not required when using BGP shortcuts.

Option C: Incorrect. Only edge routers need to be configured with BGP. Transit routers only need to support MPLS (LDP or RSVP-TE) but do not need to run BGP.

Option D: Correct. Transit routers need to support LDP (Label Distribution Protocol) or RSVP-TE (Resource Reservation Protocol-Traffic Engineering) LSPs (Label Switched Paths).

Conclusion: Option C is false because transit routers do not need to be configured with BGP.

References:

Nokia Border Gateway Protocol Fundamentals

Nokia 7750 SR OS BGP Configuration Guide

When a BGP router receives multiple routes for the same destination, it selects the best route based on several attributes in the following order of preference:

Highest local preference: Routes with the highest local preference are preferred.

Shortest AS_PATH: Routes with the shortest AS path are preferred.

Lowest MED: Routes with the lowest MED are preferred.

eBGP over iBGP: Routes learned via eBGP are preferred over iBGP routes.

Lowest IGP metric to BGP next hop.

Given the routes:

Local preference 100, MED 150, AS Path 65300 65200 (eBGP)

Local preference 100, MED 100, AS Path 63200 (iBGP)

Local preference 200, MED 150, AS Path 65400 63200 (iBGP)

Local preference 200, MED 100, AS Path 63700 (eBGP)

Route 4 has the highest local preference (200), the lowest MED (100), and is learned via eBGP. Therefore, it is the best route.

ReferencesNokia Border Gateway Protocol Fundamentals, Chapter on BGP Route Selection Process.

When an export policy is applied to a router to advertise a prefix to its eBGP peers, the local AS number is added to the AS_PATH attribute of the route update.

LOCAL_PREFERENCE is not set in eBGP updates; it is used within an AS.

NEXT_HOP is typically set to the advertising router's interface IP address.

COMMUNITY attribute is not set by default unless explicitly configured.

References:

Nokia Border Gateway Protocol Fundamentals documentation, Section 4.3 on BGP route advertisement.

A type-2 EVPN route update is used to carry host-specific information.

It includes the MAC address of the host and optionally the associated IP address.

This type of update allows for efficient MAC and IP address learning and advertisement within the EVPN.

Therefore, the type-2 EVPN route update carries a host MAC address and optionally the associated IP address.

References:

Nokia Border Gateway Protocol Fundamentals documentation, Section 11.2 on type-2 EVPN route updates.

In the given network diagram, RR1 and RR2 are route reflectors within AS 65540. The role of a route reflector is to reduce the number of iBGP peering sessions required within an AS.

Each route reflector (RR1 and RR2) should have the same cluster ID to identify the route reflector cluster they belong to.

RR1 needs to be configured with BGP settings that include its role as a route reflector with appropriate cluster ID and neighbor configurations.

Examining the given options:

Option A: This configuration shows RR1 with a cluster ID, proper BGP setup, and correct neighbors within the AS 65540, which corresponds to the network diagram.

Router bgp 65540 bgp router-id 10.16.10.1 bgp cluster-id 10.16.10.1 neighbor 10.16.10.2 remote-as 65540 neighbor 10.16.10.2 route-reflector-client neighbor 10.16.10.5 remote-as 65540 neighbor 10.16.10.5 route-reflector-client neighbor 10.16.10.6 remote-as 65540 neighbor 10.16.10.6 route-reflector-client

Option B: This option does not match as closely to the network requirements as Option A.

Option C and Option D: Both these options are duplicates and appear similar to Option B, not providing the correct configuration for RR1 as per the network diagram.

Therefore, the correct answer is Option A.

References:

Nokia Border Gateway Protocol Fundamentals documentation, Section 6.4 on Route Reflector configurations and examples.

An EVPN IP-Prefix (type 5) route update is used for Layer 3 VPNs and includes information necessary for routing within the VPLS.

It carries the IP prefix of the subnet, the VPLS's route-distinguisher (RD), and route-target (RT) values, as well as the service tunnel ID (e.g., MPLS label or VNI value).

The MAC address of an attached host is not included in a type-5 route update.

Therefore, the statement "The MAC address of an attached host." is NOT carried inside an EVPN IP-Prefix (type 5) route update.

References:

Nokia Border Gateway Protocol Fundamentals documentation, Section 10.4 on EVPN IP-Prefix route attributes.

Policy Statement Analysis: The given policy statement includes an "or" condition for matching prefixes in "List-1" or "List-2".

Action on Match: The action specified for matches is "reject".

Import Policy Behavior: When applied as an import policy, any BGP route that matches either "List-1" or "List-2" will be rejected and not allowed into the BGP table.

References:

Nokia Border Gateway Protocol Fundamentals

Nokia 7750 SR OS BGP Configuration Guide