Juniper JN0-360 Exam: NSR Switchover and BGP Peer Analysis

Determining Hitless NSR Switchover for BGP Peer

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Question

-- Exhibit --

{master}[edit]

user@router-RE0# run show task replication

Stateful Replication: Enabled -

RE modE. Master -

Protocol Synchronization Status

OSPF Complete

RIP Complete

BGP Complete

MPLS Complete

LDP Complete

{master}[edit]

user@router-RE0# run show bgp summary | find 192.168.1.1

192.168.1.1 65056 0 0 11:14 Establ inet.0: 0/0/0/0 inet.2: 0/0/0/0 bgp.l3vpn.0: 0/0/0/0

...

{backup}[edit]

user@router-RE1# run show system switchover

Graceful switchover: On -

Configuration databasE. Ready -

Kernel databasE. Synchronizing -

Peer statE. Steady State -

{backup}[edit]

user@router-RE1# run show bgp summary | find 192.168.1.1

192.168.1.1 65056 306 581 0 7 7 Idle

-- Exhibit --

Click the Exhibit button.

You have been asked to determine if an NSR switchover will be hitless for a given BGP peer.

Referring to the exhibit, which statement is true?

Answers

Explanations

Click on the arrows to vote for the correct answer

A. B. C. D.

A

Based on the provided output, the BGP session between the local router and its peer with IP address 192.168.1.1 is currently established on the master RE (router-RE0). The BGP peer is advertising 0 routes to the local router's inet.0, inet.2, and bgp.l3vpn.0 routing tables. Additionally, the task replication process for various routing protocols, including BGP, has completed on the master RE indicating that the routing protocol state information is being synchronized to the backup RE.

The backup RE (router-RE1) is currently synchronizing its kernel database with the master RE, and its configuration database is ready. The peer state is steady indicating that the backup RE is ready to take over as the master RE if necessary.

The output of "show bgp summary" command on the backup RE shows that the BGP session with the peer is currently idle. The output also shows that the peer has advertised 306 routes and received 581 routes from the local router. The number of received and advertised routes is not relevant to determining if the NSR switchover will be hitless.

Answer A is incorrect because an idle BGP session on the backup RE is expected and does not necessarily indicate that the session will flap at switchover. Answer B is the correct answer because the completion of task replication on the master RE indicates that the NSR switchover will likely be hitless for the BGP peer. Answer C is incorrect because the GRES synchronization process is not relevant to determining the hitless nature of the NSR switchover for BGP. Answer D is incorrect because an idle BGP session on the backup RE is normal and not indicative of a session flap at switchover.