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Tuesday, September 2, 2014

BGP MCQ

Q1) On what does BGP base the selection of the best path?
A) speed
B) AS routing policy =
C) number of routers to reach a destination network
D) bandwidth plus delay

Q2) Which routing method best describes BGP?
A) distance vector
B) link-state
C) path-vector=
D) hybrid of link-state and distance vector

Q3) Which two conditions are valid reasons to run BGP in an AS? (Choose two.)
A) The AS is an ISP.=
B) The AS has only a single connection to another AS.
C) Path and packet flow manipulation is required in this AS.=
D) You have a limited understanding of BGP routing and route filtering.

Q4) Which BGP message establishes a BGP session and carries the hold time and the BGP router ID?
A) BGP update message
B) BGP keepalive message
C) BGP open message =
D) BGP notification message

Q5) Which two characteristics are true for BGP? (Choose two.)
A) supports VLSM=
B) supports CIDR=
C) is an IGP
D) is not used for routing between autonomous systems

Q6) Which two statements are true for BGP route advertisements and path selection?
(Choose two.)
A) BGP selects the best path based on speed.
B) BGP routers exchange attributes.=
C) BGP advertises paths.=
D) BGP paths are not loop-free.

Q7) Which protocol does BGP use?
A) UDP port 520
B) TCP port 179=
C) IP protocol number 88
D) IP protocol number 89

Q8) Which component does a BGP update contain?
A) multiple paths and multiple networks
B) a single path and multiple networks=
C) a single path and a single network
D) multiple paths and a single network

Q9) Which BGP message is sent when an error condition is detected?
A) BGP update message
B) BGP keepalive message
C) BGP open message
D) BGP notification message=
E) BGP error message

Q10) What are three common ways to perform multihoming? (Choose three.)
A) Each ISP passes only a default route to the AS.=
B) Each ISP passes a default route and provider-owned specific routes to the AS.=
C) Each ISP passes selected provider-owned routes but no default route to the AS.
D) Each ISP passes all routes to the AS.=


Q11) Which two terms refer to routers that are configured to exchange BGP information with
one another?
A) BGP peer=
B) BGP speaker
C) BGP router
D) BGP neighbor=


Q12) By default, which two are conditions for routers to be EBGP neighbors? (Choose two.)
A) directly connected=
B) in the same AS
C) in different autonomous systems=
D) running an IGP between them to establish an adjacency


Q13) What are three ways to form an adjacency between IBGP neighbors by default?
(Choose three.)
A) The neighbors can be directly connected.=
B) The neighbors can be reachable from one another by static routes.=
C) The neighbors can be reachable from one another by a dynamic internal routing protocol.=
D) The neighbors can be in different AS.

Q14) Which statement about BGP is true?
A) Routes learned via IBGP are never sent to EBGP peers.
B) All the routers between IBGP neighbors must not be running BGP.
C) Routes learned via IBGP are never propagated to other IBGP peers.=
D) Routes are never learned via IBGP.

Q16) Which command indicates to a BGP router whether an IP address belongs to an IBGP
or an EBGP neighbor?
A) neighbor {ip-address | peer-group-name} shutdown
B) neighbor {ip-address | peer-group-name} update-source interface-type
interface-number
C) neighbor {ip-address | peer-group-name} remote-as autonomous-system=
D) neighbor {ip-address | peer-group-name} next-hop-self


Q17) Which command sets the source IP address of a BGP update to be the IP address of a
specific interface?
A) neighbor {ip-address | peer-group-name} shutdown
B) neighbor {ip-address | peer-group-name} update-source interface-type
interface-number=
C) neighbor {ip-address | peer-group-name} remote-as autonomous-system
D) neighbor {ip-address | peer-group-name} next-hop-self

Q18) Which one of these BGP network statements is valid?
A) network 199.199.199.199 mask 255.255.255.0
B) network 191.200.100.0
C) network 172.16.1.0 mask 255.255.0.0
D) network 200.100.50.0=

Q19) Which state indicates that the router does not have a path to the neighbor IP address?
A) active
B) idle=
C) established
D) open confirm

Q20) Which state indicates that an open message has been sent but a reply has not been
received from the neighbor in more than 5 seconds?
A) active=
B) idle
C) established
D) open confirm

Q21) Which command is the most disruptive method of resetting BGP sessions and should
be avoided?
A) clear ip bgp 192.168.200.1
B) clear ip bgp *=
C) clear ip bgp 192.168.200.1 soft in
D) clear ip bgp 192.168.200.1 soft out

Q22) Which command resends the routing table without resetting the TCP session and flags
routes that the neighbor, 192.168.200.1, will not see anymore as “withdrawals”? (You
should use this command if the outbound policy of a BGP router has changed.)
A) clear ip bgp 192.168.200.1
B) clear ip bgp *
C) clear ip bgp 192.168.200.1 soft in
D) clear ip bgp 192.168.200.1 soft out=

Q23) Which command is used to administratively disable a BGP neighbor?
A) neighbor {ip-address | peer-group-name} shutdown=
B) neighbor {ip-address | peer-group-name} update-source interface-type
interface-number
C) neighbor {ip-address | peer-group-name} remote-as autonomous-system
D) neighbor {ip-address | peer-group-name} next-hop-self

Q24) Which command sets the next-hop address to be the source IP address of the update
when advertising to a BGP neighbor?
A) neighbor {ip-address | peer-group-name} shutdown
B) neighbor {ip-address | peer-group-name} update-source interface-type
interface-number
C) neighbor {ip-address | peer-group-name} remote-as autonomous-system
D) neighbor {ip-address | peer-group-name} next-hop-self=

Q25) Which clear ip bgp command is the least intrusive for resetting a BGP session after
changing outbound policy for neighbor 200.100.50.1?
A) clear ip bgp *
B) clear ip bgp 200.100.50.1 soft out=
C) clear ip bgp 200.100.50.1
D) clear ip bgp 200.100.50.1 soft in

Q26) The network command that is used in the router BGP process identifies the interfaces
out of which to advertise BGP updates.
A) true
B) false=

Q27) A BGP router automatically peers with any other BGP router.
A) true
B) false=

Q28) Which BGP neighbor state is the proper state for normal BGP neighbor operations?
A) active
B) open confirm
C) idle
D) established=

Q29) Which command resets the TCP session only between a router and its neighbor,
192.168.200.1?
A) clear ip bgp 192.168.200.1=
B) clear ip bgp *
C) clear ip bgp 192.168.200.1 soft in
D) clear ip bgp 192.168.200.1 soft out

Q30) In the output of the show ip bgp command, what does the “s” in front of the line for a
network mean?
A) summarized network
B) subnet of a network
C) suppressed network=
D) supernet of a network

Q31) When authenticating between two BGP routers, the same password must be configured
on both routers.
A) true=
B) false

Q32) Which description applies to the AS path attribute?
A) well-known mandatory=
B) well-known discretionary
C) optional transitive
D) optional nontransitive

Q33) Which description applies to the next-hop attribute?
A) well-known mandatory=
B) well-known discretionary
C) optional transitive
D) optional nontransitive

Q34) Which description applies to the origin attribute?
A) well-known mandatory=
B) well-known discretionary
C) optional transitive
D) optional nontransitive

Q35) Which description applies to the local preference attribute?
A) well-known mandatory
B) well-known discretionary=
C) optional transitive
D) optional nontransitive

Q36) Which description applies to the MED attribute?
A) well-known mandatory
B) well-known discretionary
C) optional transitive
D) optional nontransitive=

Q37) Which description applies to the weight attribute?
A) well-known mandatory
B) well-known discretionary
C) optional transitive
D) proprietary to Cisco and not advertised to other BGP routers=

Q38) BGP, by default, will load-balance across how many paths?
A) 1=
B) 2
C) 4
D) 6

Q39) Which path will BGP prefer when using the weight attribute?
A) higher weight=
B) lower weight

Q40) Which path will BGP prefer when using the local preference attribute?
A) higher local preference=
B) lower local preference

Q41) Which path will BGP prefer when using the MED attribute?
A) higher MED
B) lower MED=


Q43) Place the BGP selection criteria in order from the first step to the last step evaluated to
select the BGP path that is submitted to the IP routing table.
A) _____ prefer the path with the lowest neighbor BGP router ID 10
B) _____ prefer the lowest MED 6
C) _____ prefer the shortest AS path 4
D) _____ prefer the oldest route for EBGP paths 9
E) _____ prefer the lowest origin code (IGP < EGP < incomplete) 5
F) _____ prefer the highest weight 1
G) _____ prefer the path through the closest IGP neighbor 8
H) _____ prefer the highest local preference 2
I) _____ prefer the route that was originated by the local router 3
J) _____ prefer an EBGP path over IBGP path 7
K) _____ prefer the lowest neighbor IP address 11


Q44) Which two statements are true regarding local preference? (Choose two.)
A) The higher value for local preference is preferred. =
B) Local preference is used only between EBGP neighbors.
C) The lower value for local preference is preferred.
D) Local preference is used only between IBGP neighbors.=

Q45) Which two statements are true regarding the MED? (Choose two.)
A) The higher value for the MED is preferred.
B) The MED is exchanged between autonomous systems.=
C) The lower value for the MED is preferred.=
D) The MED is local to an AS.

Q46) Which command changes the MED for all routes?
A) bgp med number
B) default-metric number=
C) default-med number
D) set med number
E) bgp default-metric number

Q47) Which command is used within a route map to change the local preference value?
A) bgp default local-preference value
B) default local-preference value
C) set local-preference value=
D) set metric value

48. What are the benefits of using a link-state routing protocol? (Choose all that apply.)
A. It uses the Hello packet to establish adjacencies.=
B. It uses several components to calculate the metric of a route.
C. Updates are sent only when changes occur in the network.=
D. It is a better protocol than distance-vector is.

49. BGP is used to advertise which of the following?
A. Network hosts
B. Network paths=
C. Network switches
D. Network servers

50. Which of the following RFCs explains autonomous systems as a set of routers under one or more administrations that present a common
routing policy to the Internet?
A. RFC 1930=
B. RFC 2047
C. RFC 2047
D. RFC 31

51. Which of the following is not an IGP?
A. RIPv2
B. IGRP
C. IPv4=
D. OSPF

52. Which of the following BGP types runs outside of an AS?
A. oBGP
B. iBGP
C. eBGP=
D. xBGP

53. Interior routing protocols operate at what layer of the OSI Reference Model?
A. Shared layer
B. Network layer=
C. Data Link layer
D. Physical layer
E. Routing layer

54. When an AS must traverse another AS to get to its destination, the traversed AS is called which of the following?
A. Complete AS
B. Forwarding AS
C. Transit AS=
D. Transistor AS

55. BGP uses which of the following TCP ports to open a session with another BGP peer?
A. Port 20
B. Port 21
C. Port 80
D. Port 179=


56. Which of the following message types must be sent by a BGP peer during the configured hold time to keep a session from terminating?
(Choose the two best answers.)
A. Non-terminate message
B. KEEPALIVE message=
C. UPDATE message=
D. TIMER message

57. Which of the following authorities is responsible for assigning ASNs?
A. ANSI
B. Internet Police
C. IEEE
D. IANA=

58. An autonomous system number is comprised of how many bits?
A. 8
B. 16=
C. 32
D. 64

59. How many entry and exit points can be found in a stub network?
A. Five
B. Four
C. Two
D. One=


60. When a BGP peer tries to open a session with another endpoint, the peer is in which of the following states?
A. Active state
B. Connection state =
C. Open state
D. Established state

This peer is in the Connection state until a message is sent to identify each peer. When the connection is established, it transitions to the
Open state. Once the other peer accepts the connection, the peer transitions to Established state. If the connection is lost, possibly due to a
version mismatch, the peer goes to the Active state and actively tries to reestablish the connection using the proper version properties.

61. Withdrawn routes are advertised in which of the following message types?
A. OPEN
B. UPDATE =
C. NOTIFICATION
D. KEEPALIVE

62. Which of the following attributes must be included in a BGP UPDATE message?
A. Well-known mandatory=
B. Well-known discretionary
C. Optional transitive
D. Optional non-transitive
E. All of the above

63. Which of the following is not a well-known mandatory attribute?
A. AS_PATH
B. COMMUNITIES=
C. ORIGIN
D. NEXT_HOP


64. Which of the following attributes is considered to be BGP’s extensive route-selection component?
A. ORIGINATOR_ID
B. MULTI_EXIT_DISCRIMINATOR=
C. CLUSTER_LIST
D. AS_PATH

65. The Network Layer Reachability Information (NLRI) field is used to identify prefixes associated with which of the following fields found in
an UPDATE message?
A. CLUSTER_LIST
B. MED
C. Total Path Attributes=
D. ORIGINATOR_ID

The NLRI field shows route prefixes with attributes identified in the Total Path Attributes field. The other answers listed are all
attributes found in the Total Path Attributes field.

66. Which of the following fields is not found in a BGP common header?
A. Marker
B. Length
C. Version=
D. Type

The Version field is not found in a BGP common header. If the common header specifies this to be a BGP OPEN message, then the
Version field will be found in the message but not in the BGP common header.

67. Which of the following is not a BGP message type?
A. OPEN
B. UPDATE
C. NOTIFICATION
D. KEEPALIVE
E. WAIT =
F. All of the above.

There is no WAIT message type. The OPEN message type is used to establish a connection between BGP peers. The NOTIFICATION
message type is used to advertise errors. The UPDATE message type is used to advertise topology updates and changes, and the KEEPALIVE
message type is sent to keep a session active when no UPDATE messages are exchanged during the established hold time.

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