Juniper Juniper Certifications JN0-643 Questions & Answers

• Question 171:

  -- Exhibit -user@SwitchA# show protocols mstp

  configuration-name region1;

  bridge-priority 16k;

  msti 1 {

  bridge-priority 16k;

  vlan [10 20];

  }

  msti 2 {

  bridge-priority 8k;

  vlan [30 40];

  }

  user@SwitchB# show protocols mstp

  configuration-name region1;

  bridge-priority 8k;

  msti 1 {

  bridge-priority 16k;

  vlan [10 20];

  }

  msti 2 {

  bridge-priority 8k;

  vlan [30 40];

  }

  user@SwitchA>monitor traffic interface xe-0/0/0 no-resolve extensive

  10:36:00.594220 Out STP 802.1s, Rapid STP, CIST Flags [Forward, Agreement], CIST bridge-id 4000.5c:5e:ab:72:da:41.8215, length 118

  message-age 0.00s, max-age 20.00s, hello-time 2.00s, forwarding-delay 15.00s CIST root-id 4000.5c:5e:ab:72:da:41, ext-pathcost 0 int-pathcost 0, port-role Designated CIST regional-root-id 4000.5c:5e:ab:72:da:41

  MSTP Configuration Name regio-2, revision 0, digest ca136a235706b316c8db8f921067a68f CIST remaining-hops 20

  MSTI 1, Flags [Proposal, Forward, Agreement], port-role Designated MSTI regional-root-id 4001.5c:5e:ab:72:da:41, pathcost 0 MSTI bridge-prio 4, port-prio 8, hops 2010:36:00.594220

  10:36:00.594223 Out 802.1s, Rapid STP, CIST Flags [Forward, Agreement], CIST bridge-id 4000.5c:5e:ab:72:da:41.8215, length 118

  message-age 0.00s, max-age 20.00s, hello-time 2.00s, forwarding-delay 15.00s CIST root-id 4000.5c:5e:ab:72:da:41, ext-pathcost 0 int-pathcost 0, port-role Designated CIST regional-root-id 4000.5c:5e:ab:72:da:41

  MSTP Configuration Name regio-2, revision 0, digest ca136a235706b316c8db8f921067a68f CIST remaining-hops 20

  MSTI 1, Flags [Proposal, Forward, Agreement], port-role Designated MSTI regional-root-id 4001.5c:5e:ab:72:da:41, pathcost 0 MSTI bridge-prio 4, port-prio 8, hops 20 -- Exhibit -

  Click the Exhibit button.

  Referring to the exhibit, a customer notices that MSTP is not converging on MSTI 2. To troubleshoot the problem, the customer captured traffic on the link (xe-0/0/0) of SwitchA connecting to SwitchB.

  Which two situations would cause the problem? (Choose two.)

  A. MSTI 1 and MSTI 2 are part of the same MSTP region.

  B. The bridge priority value of the MSTI 2 is the same on SwitchA and SwitchB.

  C. VLAN 30 and VLAN 40 are not configured on SwitchA.

  D. VLAN 30 and VLAN 40 are not members of trunk link xe-0/0/0 on SwitchA.

  Correct Answer: CD

• Question 172:

  -- Exhibit -[edit protocols] user@switch# commit [edit protocols ] 'mstp' Another xSTP protocol is enabled error : Another xSTP protocol is enabled error: configuration check-out failed -- Exhibit -

  Click the Exhibit button.

  Referring to the exhibit, a customer is receiving an error while committing the operation on the switch.

  What are two reasons for this problem? (Choose two.)

  A. VSTP and RSTP are both configured.

  B. MSTP and RSTP are both configured.

  C. Only STP is configured.

  D. MSTP and STP are both configured.

  Correct Answer: BD

• Question 173:

  -- Exhibit -- Exhibit -

  

  Click the Exhibit button.

  You are asked to allow a customer to tunnel STP BPDUs from Customer Switch1 to Customer Switch2 for VLAN 300 on S-VLAN v500. You have administrative access to SW1 and SW3, but not SW2.

  Referring to the exhibit, which three configuration statements must be added to SW1 to allow ingress STP BPDUs on port ge-0/0/16 to pass to SW3 for VLAN 300 only? (Choose three.)

  A. set vlans v500 vlan-id 500 interface ge-0/0/16.0 mapping 300 swap

  B. set vlans v500 vlan-id 500 dot1q-tunneling layer2-protocol-tunneling stp

  C. set vlans v500 vlan-id 500 interface ge-0/0/16.0 mapping 300 push

  D. set ethernet-switching-options dot1q-tunneling ether-type 0x8100

  E. set vlans v500 vlan-id 500 interface ge-0/0/20.0 mapping 300 push

  Correct Answer: BCD

• Question 174:

  Which two statements are true about SSM implementations on Junos devices? (Choose two.)

  A. There is no need for an RP.

  B. The multicast receiver's DR must have IGMPv3 enabled.

  C. SSM traffic must use the 232/8 range.

  D. ASM and SSM implementations can coexist in the same network.

  Correct Answer: AD

• Question 175:

  You are asked to establish a single EBGP peering across two physical interfaces to your ISP. Which BGP feature should you use?

  A. multipath

  B. multihop

  C. accept-remote-nexthop

  D. allow

  Correct Answer: B

• Question 176:

  -- Exhibit

  

  -- Exhibit -Click the Exhibit button.

  Referring to the exhibit, routers A, B, and C are in the same BGP AS 100. Router A prefers to route traffic through Router C.

  Which BGP attribute would you configure to ensure this behavior?

  A. as-path-prepend

  B. local-preference

  C. metric

  D. weight

  Correct Answer: B

• Question 177:

  -- Exhibit

  

  -- Exhibit -Click the Exhibit button.

  Referring to the exhibit, and given that no other BGP manipulation has been configured, how is traffic influenced from R1 to R3?

  A. Traffic is load-balanced across both paths.

  B. Traffic is preferred through AS 2493.

  C. Traffic is preferred through AS 8841.

  D. Traffic prefers the path with the lowest local preference.

  Correct Answer: C

• Question 178:

  Area 1 is configured as an NSSA with no summaries.

  Which three types of LSAs are allowed in Area 1's database? (Choose three.)

  A. Type 1

  B. Type 2

  C. Type 3

  D. Type 5

  E. Type 7

  Correct Answer: ABE

• Question 179:

  What are two benefits of configuring OSPF database protection? (Choose two.)

  A. Protects the LSDB from being flooded by excessive LSA flooding.

  B. Provides intra-area route filtering and route summarization.

  C. Allows the device to participate in OSPF routing but not be used for transit traffic.

  D. Limits the number of LSAs in the LSDB (excluding those generated by the local router).

  Correct Answer: AD

• Question 180:

  You must troubleshoot a CoS issue on an Ethernet interface which has been observed to drop packets in the best effort queue. You must determine whether the dropped packets are tail drops.

  Which CLI command output accomplishes this task?

  A. show class-of-service interface

  B. show interfaces queue

  C. show interfaces extensive

  D. show class-of-service forwarding-class best-effort

  Correct Answer: B