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
Answer : E
Which statement about MPLS TE Fast Reroute (FRR) link protection operation is not true?
Answer : B
Explanation: 1.7. MPLS Traffic Engineering The backup tunnel terminates on the merge point (MP) where traffic rejoins the primary tunnel.
Which statement about Remotely Triggered Black Hole (RTBH) is true?
Answer : A
What are the Address Family Identifier (AFI) and Subsequent Address Family Identifier
(SAFI) values for VPNv6?
Answer : E
In PIM-SM operations, the first router connected to the multicast source sends the Register
message to which device?
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.
Which four of these are MPLS label header fields? (Choose four.)
Answer : A,C,D,F
Which two statements about DS-Lite are true? (Choose two.)
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.
With the BGP peerings shown, which 3 solutions are most correct? (Choose three.)
Answer : B,D,E
What is the Cisco IOS default behavior for switching from the shared tree to the shortest
path tree in PIM-SM operations?
Answer : A
Which of the following are steps to configure destination-based Remote Triggered Black
Hole (RTBH) filtering? (Choose three.)
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).
What is the default BGP scanner time?
Answer : D
Explanation: The scanning interval of BGP routing information. Valid values are from 15 to 60 seconds. The default is 60 seconds.
When the Cisco IOS OSPF command ip ospf dead-interval minimal hello-multiplier 5 is
configured, which two statements are true? (Choose two.)
Answer : C,F
What is the importance of using Virtual Output Queues on ingress Line Cards in a high-end
Answer : C
Explanation: The 12000 uses virtual output queues to eliminate the Head of Line Blocking within the switch fabric.