Q61. An engineer is troubleshooting L3VPN traffic loss over the MPLS-enabled core network when new core links were enabled. Assuming that the IGP is properly configured, which issue causes a temporary data flow blackholing when the IGP and LDP reconvenes?
A. LDP is a Layer 2 protocol forwarding label packets before the IGP reconvened.
B. IP packets are forwarded as soon as routes are learned over a new IGP adjacency before the label exchange happens over the new links
C. MP-BGP sessions between PE and RR routers require extra time to reconverge than the underlying IGP.
D. MPLS-TE tunnels without LDP adjacencies are used over the new links black-holing the traffic before the LDP label exchange is completed
Answer: B
Q62. An engineer is working to provide high availability to a Service Provider core network. Which BGP command enables a backup path to be installed in the RIB and CEF tables?
A. maximum-paths ibgp
B. bgp additional-paths install
C. maximum-paths eibgp
D. bgp additional-paths select
E. bgp advertise-best-external
Answer: B
Explanation: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/iproute_bgp/configuration/xe-3s/irg-xe-3s-book/bgp_best_external.html#GUID-66F31B75-B1E6-4B38-9B4D-6A89839930CE
Q63. Refer to the exhibit. The Service Provider is deploying Internet service to its VRF customers by using vrf INTERNET. A dedicated firewall provides NAT functionally towards the Internet. Assume that IP address overlapping between VRFs is not an issue.
Which three configuration steps are required to add Internet service to the VRF customers? (Choose three.)
A. Export the RD of vrf INTERNET from all customer VRFs.
B. Originate a default route on PE4 in vrf INTERNET.
C. Import the RD from vrf INTERNET in all customer VRFs.
D. Originate a default route on the firewall in vrf INTERNET.
E. Import the VRF “INTERNET” Route Target in all customer VRFs.
F. Import the Route Target of all customer VRFs in vrf INTERNET.
G. Leak all VRF routes to the global routing table.
Answer: B,C,G
Q64. Two Tier 2 Service Providers are using a Tier 1 Service Provider for transport. MPLS is required between the Tier 2 Service Providers for label switching. In this CSC solution, which label stack is correct?
A. original IP packet, MPLS CSC transport label, MPLS VPN label, and MPLS Tier 2 transport label
B. original IP packet, MPLS Tier 2 transport label, MPLS VPN label, and MPLS CSC transport label
C. original IP packet, MPLS VPN label, MPLS Tier 2 transport label, and MPLS CSC transport label
D. original IP packet, MPLS Tier 2 transport label, MPLS CSC transport label, and MPLS VPN label
Answer: C
Q65. Which two statements about Unified MPLS are true? (Choose two.)
A. Unified MPLS works on Cisco IOS XR Software only.
B. Unified MPLS extends MPLS across multidomain networks in a scalable manner.
C. New technologies or protocols are not used; only MPLS, LDP, IGP, and BGP are used.
D. ABR loopback prefixes should always be redistributed from the core IGP into the aggregation IGP.
E. The RRs are part of the control path only.
Answer: B,D
Explanation: http://www.cisco.com/c/en/us/support/docs/multiprotocol-label-switching-mpls/mpls/116127-configure-technology-00.pdf
Q66. Which are the four main functions of the Cisco IOS XR System Manager? (Choose four)
A. performs system monitoring
B. is the main IOS XR component for device drivers and software installation management
C. starts, restarts, and terminates processes in response to user configuration or RP failover
D. is responsible for the message-passing "bus" for interprocess communication
E. acts as a central repository for all process-related information
F. performs health checks
G. initiates disaster recovery based on the process health
H. invokes a dumper to collect a core dump when a process terminates abnormally
Answer: C,E,G,H
Q67. Refer to the exhibit.
OSPF is already running with the default OSPF parameters. R1 has added a new subnet (loopback 11). What will occur in regards to SPT computing on R2 router?
A. Adding ispf command on R2 router, the entire SPT will be computed on R2 router.
B. Because 10.11.11.11/32 prefix information will be in a LSA type 3 on R2 router's OSPF database, R2 router will run partial SPF computation.
C. Adding ispf command on R2 router, R2 router will recompute only the affected part of tree.
D. Because 10.11.11.11/32 prefix will be a LSA type 1 on R2 router's OSPF database. R2 router will always run a full SPF computation, even though an OSPF optimization is applied on R2 router.
Answer: C
Q68. Refer to the exhibit.
IS-IS configuration has been deployed using the default IS-IS metric value and default IS-IS metric-style. The SP decides to implement MPLS TE in all routers, except R5. In order to maintain IS-IS adjacency between R3 and R5 without impacting reachability, which command should be configured on R3 router under the IS-IS process?
A. metric-style narrow
B. metric-style wide
C. metric-style narrow transition
D. metric-style transition
Answer: D
Q69. A company is deciding between an HVR and SVR solution in order to finalize a virtualization project proposal. Which is an advantage of a HVR solution versus a SVR solution?
A. A HVR solution implements dedicated data plane resources.
B. A HVR solution implements shared control plane resources.
C. A HVR solution introduces significant contention of resources.
D. A HVR solution implements dedicated chassis resources.
Answer: A
Explanation:
Comparison of Virtualized Routing Architectures
Category Hardware-Isolated Virtual Router Software-Isolated Virtual Router
Control plane resources (CPU, memory)
Dedicated
Shared
Data plane resources (forwarding engine, queues)
Dedicated
Shared
Chassis resources (power supplies, blowers, fabric)
Shared
Shared
Management, configuration
Dedicated
Typically shared, but varies depending on degree of virtualization
Connections between virtualized routing entities
Typically external
Typically internal, but possibly external
Per-chassis scalability (routing adjacencies, prefixes)
Increased with additional logical routers
Unaffected by additional virtual routers
Reference: http://www.cisco.com/en/US/solutions/collateral/ns341/ns524/ns562/ns573/white_paper_c1 1-512753_ns573_Networking_Solutions_White_Paper.html
Q70. Which is the main goal of BGPsec regards to improve BGP security?
A. Reduces risk of improper route propagation from unauthorized AS numbers
B. Configures BGP route verification by storing routes in a database used to validate AS numbers
C. Adds encryption to route propagation outside the iBGP AS
D. Increases legitimacy and authenticity of BGP advertisements
Answer: D
Explanation: Reference: https://tools.ietf.org/html/draft-lepinski-bgpsec-overview-00