Q441. Which two statements about MPLS VPNs are true? (Choose two.)
A. PE routers maintain customer routes in the VPN for that customer.
B. They use the explicit-null label by default.
C. P routers are used only for label transit.
D. P routers maintain customer routes in the VPN for that customer.
E. They support only one route target.
F. Each interface on a PE router must have its own VRF.
Answer: A,C
Q442. Which statement about passive interfaces is true?
A. The interface with the OSPF passive interface configuration appears as a not-so-stubby network.
B. The interface with the EIGRP passive interface configuration ignores routes after the exchange of hello packets.
C. The interface with the IS-IS passive interface configuration sends the IP address of that interface in the link-state protocol data units.
D. Passive interface can be configured on the interface for IS-IS.
Answer: C
Explanation:
With IS-IS, passive interfaces are used to prevent unnecessary LSA packets out that interface, but the IP address of passive interfaces are still included in updates going out the other interfaces. This behavior is what enables the best practice of configuring loopback interfaces as passive, but still having the loopback be reachable.
Q443. Which data plane protocol does EIGRP Over the Top use?
A. MPLS
B. GRE
C. LISP
D. IP-in-IP
Answer: C
Explanation:
The EIGRP Over the Top solution can be used to ensure connectivity between disparate Enhanced Interior Gateway Routing Protocol (EIGRP) sites. This feature uses EIGRP on the control plane and Locator ID Separation Protocol (LISP) encapsulation on the data plane to route traffic across the underlying WAN architecture. EIGRP is used to distribute routes between customer edge (CE) devices within the network, and the traffic forwarded across the WAN architecture is LISP encapsulated. Therefore, to connect disparate EIGRP sites, you must configure the neighbor command with LISP encapsulation on every CE in the network.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_eigrp/configuration/xe-3s/ire-xe-3s-book/ire-eigrp-over-the-top.html
Q444. Which statement about UDLD is true?
A. The udld reset command resets ports that have been error-disabled by both UDLD and Fast UDLD.
B. Fast UDLD is configured in aggressive mode.
C. Only bidirectional link failures can be detected in normal mode.
D. Each switch in a UDLD topology can send and receive packets to and from its neighbors.
Answer: A
Q445. Which field is specific to the OPSFv3 packet header, as opposed to the OSPFv2 packet header?
A. checksum
B. router ID
C. AuType
D. instance ID
Answer: D
Explanation:
In OSPFv3, Instance ID is a new field that is used to have multiple OSPF process’ instance per link. By default it is 0 and for any additional instance it is increased, instance ID has local link significance only. OSPFv3 routers will only become neighbors if the instanceIDs match. It is thus possible to have multiple routers on a broadcast domain and all run Ospfv3 but not all of them becoming neighbors.
Reference: https://supportforums.cisco.com/document/97766/comparing-ospfv3-ospfv2-routing-protocol
Q446. Which three address family types does EIGRP support? (Choose three.)
A. IPv4 unicast
B. IPv4 multicast
C. IPv6 unicast
D. IPv6 multicast
E. IPv4 anycast
F. IPv6 anycast
Answer: A,B,C
Q447. What is the function of an implicit-null label?
A. It notifies the upstream LSR to remove the top label in the label stack and forward the packet.
B. It notifies the upstream LSR to add a VPN label to the label stack.
C. It is used to statically assign a label to an IGP route.
D. It is used to identify the router ID.
Answer: A
Q448. Which two improvements do SIA-Query and SIA-Reply messages add to EIGRP? (Choose two.)
A. Stuck-in-active conditions are solved faster.
B. They prevent a route from going into the stuck-in-active state.
C. They help in the localization of the real failure in the network.
D. The EIGRP adjacency between two neighbors never goes down.
Answer: A,C
Q449. Which two protocols are used to establish IPv6 connectivity over an MPLS network? (Choose two.)
A. 6PE
B. 6VPE
C. RSVP
D. ISATAP
E. LDP
F. IPv6IP
Answer: A,B
Q450. Which neighbor-discovery message type is used to verify connectivity to a neighbor when the link-layer address of the neighbor is known?
A. neighbor solicitation
B. neighbor advertisement
C. router advertisement
D. router solicitation
Answer: A
Explanation:
IPv6 Neighbor Solicitation Message A value of 135 in the Type field of the ICMP packet header identifies a neighbor solicitation message. Neighbor solicitation messages are sent on the local link when a node wants to determine the link-layer address of another node on the same local link (see the figure below). When a node wants to determine the link-layer address of another node, the source address in a neighbor solicitation message is the IPv6 address of the node sending the neighbor solicitation message. The destination address in the neighbor solicitation message is the solicited-node multicast address that corresponds to the IPv6 address of the destination node. The neighbor solicitation message also includes the link-layer address of the source node.
Figure 1. IPv6 Neighbor Discovery: Neighbor Solicitation Message
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipv6_basic/configuration/xe-3s/ip6b-xe-3s-book/ip6-neighb-disc-xe.html