4A0-102 Sample Questions Answers

Core and edge node failure recovery depends on IGP convergence.

Edge neighbor failure is detected by the eBGP session timeout.

BGP control plane convergence is independent of number of affected prefixes.

Upon BGP control plane convergence, an optimal path is installed in the FIB.

1

2

3

None

R1-R3-R8

R1-R2-R4-R8

R1-R3-R4-R8

R1-R2-R4-R3-R8

"65100"

"65100 65200''

"65200 65100"

"65100 65250 65200"

100

250

The IGP cost

None

140000 200 135000

137000 140000 200 135000

140000 23456 135000

135000 200 140000

Import policies affect the way thelocal AS receives traffic, while export policies affect the way it sends traffic.

Import policies affect the way the local AS sends traffic, while export policies affect the way it receives traffic.

Both import and export policies affect the way thelocal AS receives traffic, but not the way it sends traffic.

Both import and export policies affect the way the local AS sends traffic, but not the way it receives traffic.

Path-ID is a four-octet identifier pre-pended to the NLRI field of aBGP update.

Path-ID is an optional transitive attribute used to advertise multiple paths.

Path-ID uniquely identifies each path advertised to a neighbor.

A BGP speaker that re-advertises a route must generate its own Path-ID.

Prefix 192.168.0.0/17 longer.

Prefix 192.168.0.0/19 longer.

Prefix 192.168.96.0/19 longer.

Prefix 192.168.0.0/18 longer.

Only thefirst route will appear in the RIB-In.

Only the second route will appear in the RIB-In.

Only the third route will appear in the RIB-In.

All routes will appear in the RIB-In.

".+ 65100"

"65100.+"

".* 65100.*"

"65100"

Router RA prefers the update received from router RR1.

Router RA prefers the update received from router RR2.

Router RA flags both updates as invalid.

Router RA accepts bothupdates and flags them as used.

Only the route reflector is configured with acluster id.

There can only be one route reflector in a cluster.

Clients should have iBGP sessions with each other to maintain the mesh.

There can only be one level of route reflectors in the topology.

Option A

Option B

Option C

Option D

Option A

Option B

Option C

Option D

Import policies affect ingress data flow.

Export policies affect ingress data flow.

Both import and export policies affect ingress data flow.

Policy direction and data flow are independent.

Routers R1, R2, R3, R4 and R5.

Routers R1and R4 only.

Routers R1, R2, R3 and R4 only.

Routers R1, R4 and R5 only.

Optional transitive attribute.

Optional non-transitive attribute.

Well-known mandatory attribute.

Well-known discretionary attribute.

The local system has received aKeepalive message and is ready to exchange updates.

The local system is exchanging Update messages with its neighbor.

The local system has sent a Keepalive message to its neighbor and is waiting to receive one back.

The local system has sent an Open message to its neighbor and is waiting to receive one back.

Both neighbors R1and R2should be part of AS 65540.

Neighbor R1should be part of AS 65550, while neighbor R2 should be part of AS 65540.

Neighbor R1should be part of AS 65550, while neighbor R2 should be part of AS 65560.

Both neighbors R1and R2 should be part of AS 65560.

64496 – 64511

1 – 56319

64512-65534

64513-65535

There are no defined private AS numbers; there are only private IP addresses.

Authentication is performed before establishing the BGP session.

Authentication can only be configuredon the group or neighbor level.

By default, MD5 authentication is disabled.

Peer authentication may be optionallyrequested in an open message.

1

2

3

4

show router route-table

showrouter bgp routes

show router bgp routes hunt

show router bgp neighbor received-routes

ISP 1 is downstream from ISP 3 and is expected to push more traffic toward ISP 3 than itpulls from it.

ISP 3 is downstream from ISP 1 and is expected to push more traffic toward ISP 1 than it pulls from it.

ISP 1 is downstream from ISP 3 and is expected to pull more traffic from ISP 3 than it pushes toward it.

ISP 3 is downstream from ISP1 and is expected to pull more traffic from ISP 1 than it pushes toward it.

AS Path of 65200, Next Hop of router A, Origin of IGP.

ASPath of 65200, Next Hop of router A, Origin of incomplete.

Null AS Path, Next Hop of router A, Origin of IGP.

Null AS Path, Next Hop of router A, Origin of incomplete.

BGP version number.

The local AS number.

The Hold Time.

Authentication.

The session between router A and router B.

The session between router C and router B.

The session between router D and router B.

Router B will learn the prefix over all of the sessions, then it will choosethe best route.

They are allocated to the RIRs by ICANN/IANA.

They are used when connecting ASs on the Internet.

They range from 1 to 56319.

They are assigned by the ISPs for enterprise networks.

Routers R6, R1, R4 and R5.

Routers R1and R4.

Routers R1, R2, R3 and R4.

Routers R2 and R3.

They must be recognized by all peers and included in all BGP updates.

They arediscarded if not recognized by the recipient.

They must be recognized by all peers and optionally included in BGP updates.

The receiving router sends a notification if a well-known discretionary attribute is not present in an update.

The router will accept the update and send a notification.

The router will not accept the update and send a notification.

The router will accept the update and ignore the attribute.

The router will accept the update and propagate the attribute.

Prefix 172.16.0.0/12 longer.

Prefix 172.31.0.0/22 longer.

Prefix 172.31.0.0/23 longer.

Prefix 172.31.0.0/24 exact.

Router R3 only.

Routers R3 and R4 only.

Routers R3, R4 and R5 only.

Router R2 does not advertise an update for the prefix.

100

The IGP cost

500

None

A single route for 192.168.0.0/16 is advertised.

BGP routes 192.168.1.0/27, 192.168.2.0/27, and 192.168.0.0/16 are advertised.

BGP routes 192.168.1.0/27 and 192.168.2.0/27 are advertised, and 192.168.0.0/16 appears as a "Blackhole" route in the route table only.

The given export policy is invalid.

Option A

Option B

Option C

Option D

Policy changes are delayed until the peer router with the affected routes reboots.

Policy changes are delayed untilroute updates for affected BGP routes are received from peers.

Policy changes are delayed until BGP sessions are cleared or BGP is reset.

Policy changes are delayed until the router reboots.

Execute a command to re-evaluate all routes in the Local-RIB against the configured export policies.

Execute a command to re-evaluate all routes in the RIB-In against the configured import policies.

Execute a command to reset the BGP session with the affected peer or peers.

No further action is required.

BGP is waiting for the TCP connection to be completed.

BGP has established a TCP connection, and an Open message has been sent to that neighbor.

The BGP session has been interrupted, and a TCP connection is being re-established.

BGPhas failed to establish a TCP connection to that neighbor, and ConnectRetry has been reset to zero.

A route received from a BGP peer within the same AS.

A route originated by a router in a different cluster of the same AS.

A route received from a BGP peer from a different member AS of a confederation.

A route received from a BGP peer fromthe same member AS of a confederation.