JN0-661 Service Provider Routing and Switching JNCIP-SP

JNCIP-SP Exam Objectives (Exam: JN0-661)

OSPF
Describe the concepts, operation and functionality of OSPFv2 or OSPFv3
OSPF area types and operations
LSA flooding through an OSPF multi-area network
DR/BDR operation
SPF algorithm
Metrics, including external metric types
Summarize and restrict routes
Virtual links
OSPFv2 vs OSPFv3
Given a scenario, demonstrate knowledge of how to configure or monitor single-area and multi-area OSPF
Implement OSPF routing policy

IS-IS
Describe the concepts, operation, or functionality of IS-IS
IS-IS areas/levels and operations
LSP flooding through an IS-IS multi-area network
DIS operation
SPF algorithm
Metrics, including wide metrics
Route summarization and route leaking
Given a scenario, demonstrate knowledge of how to configure or monitor single-area and multi-area IS-IS
Implement IS-IS routing policy

BGP
Describe the concepts, operation, or functionality of BGP
BGP route selection process
Next hop resolution
BGP attributes – concept and operation
BGP communities
Regular expressions
Multipath
Multihop
Load balancing
Advanced BGP options
BGP route damping
Multiprotocol BGP
Describe the concepts, operation or functionality of BGP scaling mechanisms
Route reflection
Confederations
Given a scenario, demonstrate knowledge of how to configure or monitor BGP
Implement BGP routing policy

Class of Service (CoS)
Describe the concepts, operation, or functionality of Junos CoS
CoS processing on Junos devices
CoS header fields
Forwarding classes
Classification
Packet loss priority
Policers, including tricolor marking and hierarchical policers
Schedulers
Drop profiles
Shaping
Rewrite rules
Hierarchical scheduling (H-CoS) characteristics (high-level only)
Given a scenario, demonstrate knowledge of how to configure or monitor CoS

IP Multicast
Describe the concepts, operation, or functionality of IP multicast
Components of IP multicast, including multicast addressing
IP multicast traffic flow
Any-Source Multicast (ASM) versus Source-Specific Multicast (SSM)
RPF – concept and operation
IGMP
PIM dense-mode and sparse-mode
Rendezvous point (RP) – concept, operation, discovery, election
SSM – requirements, benefits, address ranges
MSDP, including single and multi-PIM domains
Anycast RP
Routing policy and scoping
Given a scenario, demonstrate knowledge of how to configure or monitor IGMP, PIM-DM, PIM-SM (including SSM) and MSDP
Implement IP multicast routing policy

Advanced MPLS
Describe the concepts, operation, or functionality of MPLS
Routing table integration options for traffic engineering
Routing policy to control path selection
Advanced MPLS features
Administrative groups
Advanced CSPF options
Implement MPLS routing policy

Layer 3 VPNs
Describe the concepts, operation, or functionality of Layer 3 VPNs
Traffic flow – control and data planes
Full mesh vs. hub-and-spoke topology
VPN-IPv4 addressing
Route distinguishers
Route targets
Route distribution
Site of origin
Sham links
vrf-table-label
Layer 3 VPN scaling
IPv6 Layer 3 VPNs
Layer 3 VPN Internet access options
Given a scenario, demonstrate knowledge of how to configure or monitor the components of Layer 3 VPNs
Describe the concepts, operation or functionality of multicast VPNs
Next-generation MVPNs (NG-MVPN)
Flow of control and data traffic in an MVPN
Describe Junos support for carrier-of-carriers or interprovider VPN models

Layer 2 VPNs
Describe the concepts, operation, or functionality of BGP Layer 2 VPNs
Traffic flow – control and data planes
Forwarding tables
Connection mapping
Layer 2 VPN NLRI
Route distinguishers
Route targets
Layer 2 VPN scaling
Describe the concepts, operation, or functionality of LDP Layer 2 circuits
Traffic flow – control and data planes
Virtual circuit label
Layer 2 interworking
Describe the concepts, operation, or functionality of VPLS
Traffic flow – control and data planes
BGP VPLS label distribution
LDP VPLS label distribution
Route targets
VPLS Multihoming
Site IDs
Describe the concepts, operation, or functionality of EVPN
Traffic flow – control and data planes
MAC learning and distribution
EVPN Multihoming
BGP EVPN label distribution
Given a scenario, demonstrate knowledge of how to configure or monitor Layer 2 VPNs
BGP Layer 2 VPNs
LDP Layer 2 circuits
EVPNs
VPLS

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QUESTION 1
Which OSPFv3 router ID is valid?

A. 192.168.1.1
B. ::192.168.1.1
C. 0.0.0.0
D. 2008:db8::1

Answer: A

Explanation

OSPFv3 Router IDs, Area IDs, and LSA link-state IDs remain at the OSPFv2 IPv4 size of 32 bits.
References: Network Configuration Example OSPF Version 3 for IPv6 Feature Guide, page 3

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QUESTION 2
You are working with a new MPLS network that is using the default EXP classifier and default schedules.
A small amount of traffic is being placed in the assured
forwarding class. No other traffic is passing through the network at this time.
In this scenario, what happens to the traffic that is being placed in the assured forwarding class?

A. The traffic is reclassified to the best effort forwarding class and is forwarded.
B. The traffic remains in the assured forwarding class and is forwarded.
C. The traffic is reclassified to the network control forwarding class and is forwarded.
D. The traffic remains in the assured forwarding class and is dropped.

Answer: B

Explanation

References: https://www.juniper.net/documentation/en_US/junos15.1/topics/concept/forwarding-classes-default-cos-config-guide.html

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QUESTION 3
You are connecting your OSPF router to your customer’s RIP router and redistributing
the customer’s routes into your OSPF domain. Your OSPF routes is part of an NSSA
and the ABR is injecting an OSPF default route, which you have advertised to your customer.
After committing the configuration, you notice a routing loop
between your OSPF router and the customer’s RIP router.
Which action must you perform on your OSPF router to solve this problem?

A. Enable Type 7-to-Type 5 LSA conversion.
B. Set the customer-facing interface to passive.
C. Convert the area to a stub area.
D. Change the OSPF external route preference.

Answer: D

Explanation

Avoid routing loops by changing the OSPF external route preference.

Incorrect Answers:
A: If multiple NSSA ABR routers are present, it is recommended that not all ABRs perform
Type 7-to-5 translation to avoid routing loops.
B: We would have to make the interface on the RIP router, the customer router,
passive, not the customer-facing interface on the OSPF router.

Note: By default RIP broadcasts are sent from all interfaces. RIP allows us to control this behavior.
We can configure which interface should send RIP broadcast or
which not. Once we mark any interface as passive interface, RIP will stop sending updates from that interface.

References: https://www.juniper.net/documentation/en_US/junos15.1/topics/topic-map/ospf-stub-and-not-so-stubby-areas.html

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QUESTION 4
A PE provides VLAN VPLS service to a CE attached with two links.
You want to prevent Layer 2 loops and provide link redundancy.
Which two actions will accomplish this task? (Choose two.)

A. Place both interfaces in a link aggregation group.
B. Configure different VLANs on each interface.
C. Configure all VLANs on both interfaces, on the PE, and on the CE.
D. Configure Spanning Tree Protocol between the PE and the CE.

Answer: B,D

Explanation

D: To prevent the formation of Layer 2 loops between the CE devices and the multihomed PE routers,
Juniper recommends that you employ the Spanning Tree
Protocol (STP) on your CE devices. Layer 2 loops can form due to inconfiguration.
Temporary Layer 2 loops can also form during convergence after a change in the network topology.

References: https://www.juniper.net/documentation/en_US/junos16.1/topics/topic-map/vpls-bgp-multihoming.html

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