Juniper Juniper Certifications JN0-361 Questions & Answers

• Question 191:

  Which VPN technology allows remote locations to appear as a single LAN segment?

  A. VPLS

  B. CCC

  C. Layer 3 VPN

  D. L2PT

  Correct Answer: A

  VPLS is a virtual private network (VPN) technology. A VPLS is a provider service that emulates the full functionality of a traditional Local area network (LAN). A VPLS makes it possible to interconnect several LAN segments over a packet switched network (PSN) and makes the remote LAN segments behave as one single LAN.

  References: Encyclopedia Of Information Technology (2007) , page 535

• Question 192:

  Which OSPF state indicates that the router has finished transmitting its database but is still receiving database information?

  A. Loading

  B. ExStart

  C. 2Way

  D. Exchange

  Correct Answer: A

  In the loading state, routers send link-state request packets. During the adjacency, if a router receives an outdated or missing link-state advertisement (LSA), it requests that LSA by sending a link-state request packet.

  Note: OSPF states for adjacency formation are Down, Init, Attempt, 2-way, Exstart, Exchange, Loading and Full.

  Incorrect Answers:

  B: After two OSPF neighboring routers establish bi-directional communication and complete DR/BDR election (on multi-access networks), the routers transition to the exstart state. In this state, the neighboring routers establish a master/slave relationship and determine the initial database descriptor (DBD) sequence number to use while exchanging DBD packets.

  C: The 2-way state indicates that the router has seen its own Router ID in the Neighbor field of the neighbor's HELLO packet. Receiving a Database Descriptor (DBD) packet from a neighbor in the init state will also a cause a transition to 2- way state.

  D: Once the master/slave relationship has been negotiated (the router with the highest Router-ID becomes the master), the neighboring routers transition into the exchange state. In this state, the routers exchange DBD packets, which describe their entire link-state database. The routers also send link-state request packets, which request more recent link-state advertisements (LSA) from neighbors.

  References: http://www.cisco.com/c/en/us/support/docs/ip/open-shortest-path-first-ospf/1369929.html#anc10

• Question 193:

  You are asked to configure and apply a new routing policy to influence routing advertisements sent to a specific EBGP peer. You must ensure that the new policy does not impact routing advertisements sent to any other peer.

  In this scenario, which statement is true?

  A. The new policy should be applied as an export policy for the EBGP group in which the peer is defined.

  B. The new policy should be applied as an import policy for the EBGP group in which the peer is defined.

  C. The new policy should be applied as an export policy for the specific EBGP peer.

  D. The new policy should be applied as an import policy for the specific EBGP peer.

  Correct Answer: A

  References: https://www.juniper.net/techpubs/en_US/junos15.1/topics/concept/conditional-prefix-installingoverview.html

• Question 194:

  Which two BGP attributes influence traffic coming into an AS? (Choose two.)

  A. local preference

  B. next hop

  C. MED

  D. origin

  Correct Answer: AB

  A: The LOCAL_PREF attribute is a well-known attribute that represents the network operator's degree of preference for a route within the entire AS. The larger the value of the local preference, the more preferable the route is.

  B: The BGP NEXT_HOP is a well-known mandatory attribute. The Next Hop attribute is set when a BGP speaker advertises a prefix to a BGP speaker outside its local autonomous system (it may also be set when advertising routes within an AS, this will be discussed in later sections). The Next Hop attribute may also serve as a way to direct traffic to another speaker, rather than the speaker advertising the route itself

  References: http://www.informit.com/articles/article.aspx?p=331613andseqNum=5

• Question 195:

  Which protocol do two MC-LAG devices use to exchange control information?

  A. VRRP

  B. BFD

  C. VCCP

  D. ICCP

  Correct Answer: D

  The MC-LAG devices use Inter-Chassis Control Protocol (ICCP) to exchange the control information between two MC-LAG network devices.

  References: https://www.juniper.net/documentation/en_US/junos14.2/topics/usage-guidelines/interfacesconfiguring-multi-chassis-link-aggregation.html

• Question 196:

  Which statement is true when a VRRP master owns the VIP address?

  A. The VRRP priority will be set to 128.

  B. The VRRP priority will be set to 100.

  C. The VRRP priority will be set to 0.

  D. The VRRP priority will be set to 255.

  Correct Answer: D

  Switches configured with VRRP share a virtual IP address, which is the address you configure as the default route on the hosts. At any time, one of the switches is the VRRP master, meaning that it owns the virtual IP address and is the active default gateway. The other devices are backups. The switches dynamically assign master and backup roles based on priorities that you configure (1 through 255). If the master fails, the backup switch with the highest priority becomes the master within a few seconds. This is done without any interaction with the hosts.

  References: http://www.juniper.net/documentation/en_US/junos15.1/topics/concept/vrrp-qfx-series.html

• Question 197:

  Which two statements correctly describe MPLS penultimate-hop popping (PHP)? (Choose two.)

  A. In the Junos OS, PHP is disabled by default.

  B. With PHP enabled, the router upstream from the egress router pops the MPLS label.

  C. In the Junos OS, PHP is enabled by default.

  D. With PHP enabled, the egress router pops the MPLS label.

  Correct Answer: BC

  B: In penultimate-hop popping, the final MPLS label is popped from the IP packet at the last provider router in the network before being forwarded to the PE router. The PE router receives the packet and checks the IP address, and then the packet is forwarded to its destination.

  C: Ultimate-hop popping is disabled by default on LSPs. Penultimate-hop popping is the default behavior.

  References: http://www.juniper.net/documentation/en_US/junos15.1/topics/reference/configurationstatement/ultimate-hop-popping-edit-protocols-mpls.html

• Question 198:

  Which fields are added to an Ethernet frame when using Q-in-Q?

  A. S-VLAN and C-VLAN

  B. S-VLAN and D-VLAN

  C. P-VLAN and D-VLAN

  D. P-VLAN and C-VLAN

  Correct Answer: A

  IEEE 802.1ad is an Ethernet networking standard informally known as QinQ and is an amendment to IEEE

  standard IEEE 802.1Q-1998.

  The conventions for 802.1ad terminology typically are as follows:

  The inner tag is the tag which is closest to the payload portion of the frame; it is officially called C-TAG

  (Customer tag, with ethertype 0x8100).

  The outer tag is the one closer/closest to the Ethernet header; its name is S-TAG (Service tag, ethertype

  0x88a8).

  References: https://en.wikipedia.org/wiki/IEEE_802.1ad

• Question 199:

  You have multiple Layer 3 VPNs supporting your various customers. Some of the customers use overlapping IP address space.

  What is used to ensure each customer's prefixes are unique?

  A. route target

  B. MP-BGP

  C. BGP communities

  D. route distinguisher

  Correct Answer: D

  A route distinguisher (RD) distinguishes one set of routes (one VRF) from another. It is a unique number prepended to each route within a VRF to identify it as belonging to that particular VRF or customer. An RD is carried along with a route via MP-BGP when exchanging VPN routes with other PE routers.

  Incorrect Answers:

  A: Route targets can be used to share routes.

  References: http://packetlife.net/blog/2013/jun/10/route-distinguishers-and-route-targets/

• Question 200:

  While troubleshooting IS-IS on a broadcast network with multiple IS-IS routers, you notice that hello packets from Router A are sent every three seconds while the hello packets from Router B are sent every nine seconds. Both Router A and Router B are configured with default IS-IS configuration values.

  In this scenario, which two statements are true? (Choose two.)

  A. Router B is a non-DIS router.

  B. Router B is the DIS router.

  C. Router A is the DIS router.

  D. Router A is a non-DIS router.

  Correct Answer: AC

  The DIS Router sends CSNPs describing all the LSPs in the database every 3 seconds.

  References: http://www.cisco.com/en/US/products/ps6599/products_white_paper09186a00800a3e6f.shtml