Juniper Juniper Certifications JN0-361 Questions & Answers

• Question 101:

  -- Exhibit -

  [edit protocols bgp]

  user@router# show

  group internal {

  neighbor 10.0.16.2;

  }

  The exhibit shows a partial configuration fo an internal BGP session.

  Which two statements must be added to complete the configuration? (Choose two.)

  A. a local-address statement

  B. a type ibgp statement

  C. a next-hop-self statement

  D. a type internal statement

  Correct Answer: AD

  Based on the scenario, you would need to add the local-address and type internal statements. A configuration error will occur if these statements are not added.

• Question 102:

  -- Exhibit -

  [edit protocols bgp] user@router# show group external { neighbor 10.0.21.2; }

  The exhibit shows a partial configuration for an external BGP session.

  What must be added to complete the configuration?

  A. the type external statement

  B. the peer-as statement

  C. the multi-hop statement

  D. the next-hop-self statement

  Correct Answer: B

  Based on the exhibit, you need to add the peer-as statement. Adding this statement is necessary to indicate that the peer's AS value is different from that of the local device.

• Question 103:

  Which criterion is evaluated first when selecting a BGP route?

  A. MED

  B. origin

  C. local preference

  D. AS-path

  Correct Answer: C

  When a Junos device receives two similar route advertisements from different BGP peers, it will select the route will the lowest MED value. BGP route selection proceeds in this manner:

  Prefer the highest local-preference value

  Prefer the shortest AS-path length

  Prefer the lowest origin value

  Prefer the lowest MED value

  Prefer routes learned from an EBGP peer over an IBGP peer

  Prefer best exit from AS

  For EBGP-receive routes, prefer the current active route:

  otherwise, prefer routes from the peer with the lowest RID

  Prefer paths with the shortest cluster length

  Prefer routes from the peer with the lowest peer ID

• Question 104:

  What are the differences between EBGP and IBGP?

  A. EBGP peering requires a full mesh because EBGP speakers cannot readvertise EBGP-learned routes

  B. IBGP peering requires a full mesh because IBGP speakers cannot readvertise IBGP-learned routes

  C. Both EBGP and IBGP require a full mesh because BGP speakers cannot readvertise BGP-learned routes

  D. EBGP speakers can use route reflectors or confederations to avoid the full-mesh requirement

  Correct Answer: B

  There must be a full mesh of iBGP sessions, in other words: each BGP router within an AS must have iBGP sessions with all other BGP routers in the AS. By requiring that all information in iBGP is learned directly from the router that learned the information over eBGP, there can't be any loops in iBGP. The full mesh requirement can be solved using either route reflectors or confederations.

• Question 105:

  Which three statements area true regarding BGP local preference? (Choose three.)

  A. A higher value is preferred over a lower value

  B. A lower value is preferred over a higher value

  C. Local preference is not shared between autonomous systems

  D. Local preference can be altered by policy or configuration

  E. Local preference has a default value of 128

  Correct Answer: ACD

  A higher local preference value is preferred over a lower value. These values are not shared between autonomous systems, and can be altered by policy or configuration. you can use the local preference attribute to direct outbound traffic through a specific peer.

• Question 106:

  Using industry best practices, which BGP attribute would you modify to influence how traffic leaves your network?

  A. MED

  B. local preference

  C. AS-path

  D. communities

  Correct Answer: B

  The BGP local-preference attribute can be used to influence how traffic leaves your network. BGP uses the local-preference attribute only within an AS. Local preference values are not transmitted across EBGP links.

• Question 107:

  

  In the exhibit, all devices are sending routes to Router B. Which routes will be advertised from Router B to Router C?

  A. BGP routes learned from Router A only

  B. BGP routes learned from Router E only

  C. BGP routes learned from Routers D and E only

  D. BGP routes learned from Routers A, D, and E

  Correct Answer: C

  Router B will advertise BGP routes learned from Routers D and E to Routers A and C (EBGP to IBGP). A BGP router never readvertises IBGP learned routes to other IBGP peers.

• Question 108:

  Which two commands would you use to see the export policy that has been applied to a BGP neighbor? (choose two.)

  A. show bgp neighbor

  B. show bgp summary

  C. show bgp group

  D. show bgp policy

  Correct Answer: AC

• Question 109:

  Which method can be used to reduce the size of the upstream BGP routing table?

  A. confederations

  B. prefix aggregation

  C. atomic aggregate

  D. route reflection

  Correct Answer: B

  Prefix aggregation is a method that can be used to reduce the size of upstream BGP routing tables. This method is commonly used in ISP deployments of BGP.

• Question 110:

  Once the initial route exchange has been completed, how frequently does BGP automatically sent route updates?

  A. every hour

  B. when the configured timer expires

  C. whenever a routing policy is updated

  D. as needed

  Correct Answer: D

  Once the initial route exchange has been completed BGP automatically sends route updates as needed.

  BGP uses TCP to provide reliable communication, which ensures that BGP neighbors never miss an update. A system of keepalives also allows each BGP peer to ensure that its neighbors are still function properly. If a neighbor goes down, the BGP speaker deletes all routes learned from that peer and updates its other peers accordingly.