Juniper Juniper Certifications JN0-347 Questions & Answers

• Question 51:

  Which two statements are true about the IRB interface? (Choose two.)

  A. An IRB interface is a Layer 3 VLAN interface.

  B. An IRB interface is a Layer 2 VLAN interface.

  C. An IRB interface is used to route traffic between VLANs.

  D. An IRB interface cannot be associated with any VLAN.

  Correct Answer: AC

• Question 52:

  Click the Exhibit button.

  

  A routing table contains multiple BGP routes to the same destination prefix. The route preference is the

  same for each route.

  Referring to the exhibit, which route would be selected?

  A. route B

  B. route D

  C. route A

  D. route C

  Correct Answer: B

• Question 53:

  Which connection method do OSPF routers use to communicate with each other?

  A. IP protocol number 89

  B. TCP port 179

  C. UDP port 179

  D. IP protocol number 6

  Correct Answer: C

• Question 54:

  Which two port security features are dependent on the DHCP snooping database? (Choose two.)

  A. MAC limiting

  B. dynamic ARP inspection

  C. IP source guard

  D. storm control

  Correct Answer: BC

  B: Dynamic ARP inspection (DAI) prevents Address Resolution Protocol (ARP) spoofing attacks. ARP requests and replies are compared against entries in the DHCP snooping database, and filtering decisions are made on the basis of the results of those comparisons.

  C: IP source guard mitigates the effects of IP address spoofing attacks on the Ethernet LAN. With IP source guard enabled, the source IP address in the packet sent from an untrusted access interface is validated against the SourceDSN MAC address in the DHCP snooping database. The packet is forwarded if the source IP-MAC binding is valid; if the binding is not valid, the packet is discarded. You enable IP source guard on a VLAN. EX Series switches support IPv6 source guard also.

• Question 55:

  What are three components that populate the Ethernet switching table? (Choose three.)

  A. the interface on which the traffic was received

  B. the MAC address of the destination node

  C. the MAC address of the source node

  D. the link state

  E. the time the address was learned

  Correct Answer: ACE

• Question 56:

  Click the Exhibit button. Referring to the exhibit, which statement is true?

  

  A. R3 has the complete OSPF database.

  B. R3 and R4 have an adjacency state of Full.

  C. R4 is elected as the DR.

  D. R1 and R2 are elected as DROTHERs.

  Correct Answer: AC

  C: In LANs, the election of the designated router takes place when the OSPF network is initially established. When the first OSPF links are active, the routing device with the highest router identifier (defined by the router-id configuration value, which is typically the IP address of the routing device, or the loopback address) is elected the designated router.

• Question 57:

  Which state indicates that the BGP session is fully converged?

  A. Connect

  B. Up

  C. Established

  D. Active

  Correct Answer: C

  In order to make decisions in its operations with peers, a BGP peer uses a simple finite state machine (FSM) that consists of six states: Idle; Connect; Active; OpenSent; OpenConfirm; and Established. In the Established state, the peers send Update messages to exchange information about each route being advertised to the BGP peer.

• Question 58:

  Click the Exhibit button.

  

  Referring to the exhibit, which statement explains why the route to 192.168.178.0/24 advertised from

  192.168.35.90 is hidden?

  A. The import routing policy rejected the route.

  B. The AS path contains invalid confederation attributes.

  C. The next-hop address is a multicast address.

  D. The AS path contains a zero.

  Correct Answer: A

• Question 59:

  Switch-1 in the exhibit receives a packet from User A with a destination MAC address of

  00:26:88:02:74:47.

  Which statement is correct in this scenario?

  A.

  Switch-1 floods the packet out ge-0/0/6, ge-0/0/7, ge-0/0/8, and ge-0/0/9.

  B.

  Switch-1 floods the packet out ge-0/0/7 and ge-0/0/8.

  C.

  Switch-1 floods the packet out ge-0/0/7, ge-0/0/8, and ge-0/0/9.

  D.

  Switch-1 sends the packet out ge-0/0/7 only.

  

  Correct Answer: C

  To forward a frame destined to that specific mac -address, it will know out of which port to send the frame. Flooding however occurs when the switch does not know of the destination mac - address? say the switch has not learnt that mac address yet; or maybe that specific entry expired so it got flushed away from the mac-address table. To ensure the frame reaches its intended destination, the switch will replicate that frame out of all ports, less the port where the frame was received that's flooding.

• Question 60:

  Which three BGP attributes are well-known and mandatory? (Choose three.)

  A. AS Path

  B. Next Hop

  C. MED

  D. Local Preference

  E. Origin

  Correct Answer: ABE