350-029 CCIE SP Written Exam, V3.0

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Question 1

Cisco IOS XR has implemented a nonstop routing feature so that when RP failover occurs,
the routing information can be recovered locally. Which protocol does not support the NSR
feature?

  • A. OSPF
  • B. LDP
  • C. BGP
  • D. IS-IS
  • E. RSVP


Answer : E

Question 2

Which statement about MPLS TE Fast Reroute (FRR) link protection operation is not true?

  • A. It requires a next-hop backup tunnel.
  • B. The backup tunnel terminates on the same tail-end router as the primary tunnel.
  • C. The point of local repair (PLR) swaps the label and pushes the backup label.
  • D. The restoration time is expected to be under 50 ms.
  • E. The backup tunnel can have associated bandwidth capacity


Answer : B

Explanation: 1.7. MPLS Traffic Engineering The backup tunnel terminates on the merge point (MP) where traffic rejoins the primary tunnel.

Question 3

Which statement about Remotely Triggered Black Hole (RTBH) is true?

  • A. Route tagging is one of the techniques used by RTBH
  • B. It is used for BGP authentication
  • C. It cannot work with static routes
  • D. It uses extended ACLs for blocking attacks by creating a black hole
  • E. Before configuring RTBH. LDP must be enabled on the interface


Answer : A

Question 4

What are the Address Family Identifier (AFI) and Subsequent Address Family Identifier
(SAFI) values for VPNv6?

  • A. AFI is 2, SAFI is 96
  • B. AFI is 2, SAFI is 64
  • C. AFI is 1, SAFI is 64
  • D. AFI is 1, SAFI is 128
  • E. AFI is 2, SAFI is 128


Answer : E

Question 5




Answer :

Question 6

In PIM-SM operations, the first router connected to the multicast source sends the Register
message to which device?

  • A. Designated Router (DR)
  • B. Multicast source
  • C. Multicast receiver
  • D. RP mapping agent
  • E. RP


Answer : E

Explanation: A multicast data sender just starts sending data destined for a multicast group. The sender's local router (DR) takes those data packets, unicast-encapsulates them, and sends them directly to the RP. The RP receives these encapsulated data packets, decapsulates them, and forwards them onto the shared tree. The packets then follow the (*,G) multicast tree state in the routers on the RP Tree, being replicated wherever the RP Tree branches, and eventually reaching all the receivers for that multicast group. The process of encapsulating data packets to the RP is called registering, and the encapsulation packets are known as PIM Register packets.

Question 7

Which four of these are MPLS label header fields? (Choose four.)

  • A. Label
  • B. VPI VCI
  • C. EXP
  • D. TTL
  • E. FCS
  • F. S flag


Answer : A,C,D,F

Question 8

Which two statements about DS-Lite are true? (Choose two.)

  • A. IPv4 packets are carried over IPv6 tunnels to the LSN while IPv6 traffic is forwarded natively.
  • B. Ipv6 packets are carried over IPv4 tunnels to the LSN while IPv4 traffic is forwards natively.
  • C. The LSN performs NAT44 on private IPv4 source addresses.
  • D. DS-Lite does not perform any address translation.


Answer : A,C

Explanation: ReferencE. "Understanding Dual-Stack Lite" http://www.networkworld.com/community/node/46600 Dual-Stack Lite is a promising approach that takes the best of NAT464 while avoiding its problems: It uses IPv6-only links between the provider and the customer, but does not use NAT64 translation. When a device in the customer network sends an IPv4 packet to an external destination, the IPv4 packet is encapsulated in an IPv6 packet for transport into the provider network. At the LSN, the packet is decapsulated and NAT44 isperformed.

Question 9

With the BGP peerings shown, which 3 solutions are most correct? (Choose three.)


  • A. rtrA and rtrD are route-reflector-clients; rtrB and rtrC are route reflectors part of the same cluster.
  • B. rtrA and rtrD are route-reflector-clients; rtrB and rtrC are route reflectors part of the different cluster.
  • C. rtrA, rtrB and rtrC are part of a confederation sub-AS and rtrD is part of a different confederation sub-AS
  • D. rtrA, rtrB are part of one confederation sub-AS and rtrC, rtrD are part of a different confederation sub-AS
  • E. rtrA, rtrB and rtrC are part of a confederation sub-AS where rtrB is a route reflector and rtrA, rtrC are routereflector-clients.


Answer : B,D,E

Question 10

What is the Cisco IOS default behavior for switching from the shared tree to the shortest
path tree in PIM-SM operations?

  • A. immediately after receiving the first packet on the shared tree for a given (S, G)
  • B. after receiving over 1 kb/s traffic on the shared tree for a given (S, G)
  • C. 10 seconds after receiving the first packet on the shared tree for a given (S, G)
  • D. 30 seconds after receiving the first packet on the shared tree for a given (S, G)
  • E. after receiving over 10 kb/s traffic on the shared tree for a given (S, G)


Answer : A

Question 11

Which of the following are steps to configure destination-based Remote Triggered Black
Hole (RTBH) filtering? (Choose three.)

  • A. Configure BGP between trigger and black hole routers.
  • B. Configure OSPF between trigger router and black hole routes
  • C. Configure all edge routers with static (reserved) host route to Null0
  • D. Configure on trigger router to advertise victim host route with community
  • E. Activate black hole by redistributing route for victim into BGP with next-hop set to the static (reserved) hostroute configured on edge routers.


Answer : A,C,E

Explanation: The three steps in destination-based black hole filtering are summarized below. Step 1. The setup (preparation) A trigger is a special device that is installed at the NOC exclusively for the purpose of triggering a black hole. The trigger must have an iBGP peering relationship with all the edge routers, or, if using route reflectors, it must have an iBGP relationship with the route reflectors in every cluster. The trigger is also configured to redistribute static routes to its iBGP peers. It sends the static route by means of an iBGP routing update. Step 2. The trigger An administrator adds a static route to the trigger, which redistributes the route by sending a BGP update to all its iBGP peers, setting the next hop to the target destination address under attack as 192.0.2.1 in the current example. The PEs receive their iBGP update and set their next hop to the target to the unused IP address space 192.0.2.1. The route to this address is set to null0 in the PE, using a static routing entry in the router configuration. The next hop entry in the forwarding information base (FIB) for the destination IP (target) is now updated to null0. All traffic to the target will now be forwarded to Null0 at the edge and dropped. Step 3. The withdrawal Once the trigger is in place, all traffic to the target destination is dropped at the PEs. When the threat no longer exists, the administrator must manually remove the static route from the trigger, which sends a BGP route withdrawal to its iBGP peers. This prompts the edge routers to remove the existing route for the target that ispointed to 192.0.2.1 and to install a new route based on the IGP routing information base (RIB).

Question 12




Answer :

Question 13

What is the default BGP scanner time?

  • A. 10 minutes
  • B. 5 minutes
  • C. 120 seconds
  • D. 60 seconds
  • E. 30 minutes


Answer : D

Explanation: The scanning interval of BGP routing information. Valid values are from 15 to 60 seconds. The default is 60 seconds.

Question 14

When the Cisco IOS OSPF command ip ospf dead-interval minimal hello-multiplier 5 is
configured, which two statements are true? (Choose two.)

  • A. OSPF hello interval is 5 seconds
  • B. OSPF hello interval is 1 second
  • C. OSPF dead interval is 1 second
  • D. OSPF dead interval is 5 seconds
  • E. OSPF dead interval is 20 seconds
  • F. OSPF hello interval is 0.2 second


Answer : C,F

Question 15

What is the importance of using Virtual Output Queues on ingress Line Cards in a high-end
router?

  • A. Increases forwarding performance
  • B. Simplifies configuration
  • C. Prevents head-of-line blocking
  • D. Uses less memory


Answer : C

Explanation: The 12000 uses virtual output queues to eliminate the Head of Line Blocking within the switch fabric.

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