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

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.

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.

Local Preference Comparison: Local preference is the first criterion BGP uses to select the best path. The higher the local preference, the more preferred the route. Here, the first route has a local preference of 150, while the other two routes have a local preference of 100.

Best Path Selection: Since the first route has the highest local preference (150), it will be preferred over the other two routes regardless of the AS Path length or any other attributes.

RIB-Out: The RIB-Out (Routing Information Base - Outbound) contains the routes selected for advertisement to peers. As only the best path is advertised, only the first route with the highest local preference will be included in the RIB-Out.

References:

Nokia Border Gateway Protocol Fundamentals

RFC 4271 - A Border Gateway Protocol 4 (BGP-4)

Route Reflector (RR) Basics: In a BGP network, route reflectors are used to reduce the need for a full mesh of iBGP sessions.

Cluster ID: The route reflector (RR) is configured with a cluster ID to identify the cluster it belongs to. This prevents routing loops within the cluster.

RR Client Configuration: Only the RR needs to have the cluster ID configured; the clients do not need this configuration.

Topology Flexibility: Multiple RRs can exist in a single cluster, and clients do not need iBGP sessions with each other, reducing complexity.

References:

Nokia Border Gateway Protocol Fundamentals

RFC 4456 - BGP Route Reflection: An Alternative to Full Mesh iBGP

IPv6 Link-Local addresses are specific types of addresses used within a single local network segment. Here are key points about IPv6 Link-Local addresses:

A. True: Every physical interface running IPv6 is assigned a Link-Local address automatically.

B. True: Link-Local addresses are only valid for communication within the same broadcast domain (i.e., the local link).

C. True: They all have the same 64-bit subnet prefix (FE80::/64).

The false statement is:

D. False: The interface ID for Link-Local addresses is not derived from the interface’s IPv4 address. Instead, it is typically generated from the interface’s MAC address or using a random number.

ReferencesNokia Border Gateway Protocol Fundamentals, Chapter on IPv6 Addressing.

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

The statement "iBGP peers have to be adjacent to each other" is false. In reality, iBGP peers do not need to be directly connected. They can be several hops away from each other as long as they have IP reachability. The iBGP sessions are typically established using loopback interfaces to ensure session stability.

A. True: Peers need to be IP reachable to establish a BGP session.

B. True: Route reflectors can reduce the number of iBGP sessions required.

C. False: iBGP peers do not have to be adjacent.

D. True: The multihop parameter needs to be configured when eBGP peers are not directly connected.

ReferencesNokia Border Gateway Protocol Fundamentals, Chapter on BGP Peering and Sessions.

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.

Route Reflector (RR) Basics: In a BGP network, route reflectors help reduce the need for a full mesh of iBGP sessions. Each route reflector assigns a cluster ID to identify the cluster it belongs to and avoid routing loops.

Cluster-ID: When multiple route reflectors have the same cluster ID, a router receiving routes from these reflectors will use the cluster ID to identify if the routes have been advertised by the same cluster.

Duplicate Routes: If a route is received from different route reflectors with the same cluster ID, the receiving router (RA) will detect this as a duplicate advertisement from the same cluster.

Invalid Route Handling: BGP protocol dictates that routes received from the same cluster ID will be flagged as invalid to prevent potential routing loops.

Conclusion: Router RA flags both updates for prefix 192.168.1.0/27 received from RR1 and RR2 as invalid because they have the same cluster ID.

References:

Nokia Border Gateway Protocol Fundamentals

RFC 4456 - BGP Route Reflection: An Alternative to Full Mesh iBGP