400-201 Exam - CCIE SP Written v4.0

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Q1. What are three actions that the control word performs in MPLS AToM? (Choose three.) 

A. is used to identify the VC label 

B. is used for padding small packets 

C. preserves the sequence of the transported frames 

D. facilitates the load balancing of AToM packets in the MPLS backbone network 

E. carries control bits of the Layer 3 header of the transported protocol 

F. is used to identify the tunnel label 

Answer: B,C,D 

Explanation: https://ccdewiki.wordpress.com/2013/05/28/control-word-on-atom/ 

Q2. Refer to the exhibit. 

Customer ABC is peering with two service providers for Internet Access In order to prevent the AS100 from becoming a transit AS between ISP_1 and ISP_2 Which BGP configuration must be applied to achieve this goal? 

A. CE1# 

ip as-path access-list 1 permit ^$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.2.2 route-map LOCAL_ONLY in 

CE2# 

ip as-path access-list 1 permit ^$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.1.2 route-map LOCAL-ONLY in 

B. CE1# 

ip as-path access-list 1 permit ^11$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

, router bgp 100 

neighbor 1.1.1.2 route-map LOCAL_ONLY out 

CE2# 

ip as-path acctss-list 1 permit ^22$ 

router-map LOCAL.ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.1.2 routt-map LOCAL_ONLY out 

C. CE1# 

ip as-path access-list 1 permit ^$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.2.2 route-map LOCAL_ONLY out 

CE2# 

ip as-path access-list 1 permit ^$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.1.2 route-map LOCAL_ONLY out 

D. CE1# 

ip as-path access-list 1 permit ^100$ 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.2.2 route-map LOCAL_ONLY out 

CE2# 

ip as-path access-list 1 permit ^100S 

route-map LOCAL_ONLY permit 10 

match as-path 1 

router bgp 100 

neighbor 1.1.1.2 route-map LOCALJDNLY out 

Answer:

Q3. The following congestion avoidance configuration has been applied on an outgoing interface: 

Which is the result of the egress packets marked as DSCP AF32 when the average queue depth is 40? 

A. It will be dropped with a random rate less than the one defined by MPD. 

B. It will be tail dropped. 

C. It will be dropped with a rate of 1 packet out of 30. 

D. It will be dropped with a rate of 1 packet out of 20. 

Answer:

Q4. Refer to the exhibit. What is the correct action to fix the L2TPv3 configuration? 

A. At Router-A, correct the local interface in the pseudowire configuration. 

B. At Router-B, correct the encapsulation in the pseudowire configuration. 

C. At Router-A, correct the encapsulation in the pseudowire configuration. 

D. At Router-B, correct the local interface in the pseudowire configuration. 

Answer:

Explanation: 

http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/l2tpv30s.html#wp1046765 

Q5. Refer to the exhibit. R2 and R3 cannot install IS-IS IPv6 routes. What is the root cause? 

A. R2 is missing the metric-style wide command under the IS-IS process. 

B. R3 is missing the multi-topology transition command under the IS-IS address-family IPv6 process. 

C. R2 is missing the multi-topology command under the IS-IS address-family IPv6 process. 

D. R3 is missing the metric-style wide command under the IS-IS process. 

Answer:

Q6. In which three ways do PE routers manage multiple customers in MPLS VRF environments? (Choose three.) 

A. Route targets are configured that allow the PE to uniquely identify the customer routes in MP-BGP 

B. PE routers use route distinguishers to tag routes for importing and exporting into customer VRFs. 

C. PE routers use PE-CE routing protocols to manage routing with client VRF devices. 

D. PE routers use route targets to tag routes for importing and exporting into customer VRFs. 

E. Route distinguishes are configured that allow the PE to uniquely identify the customer routes in MP-BGP. 

F. PE routers use PE-PE routing protocols to manage routing with client VRF devices. 

Answer: C,D,E 

Q7. QoS is applied on an outgoing interface as shown below: 

What will the QoS result be for egress traffic with an average queue depth of 40 that is marked as DSCP AF32? 

A. Traffic will be dropped with a random rate less than the one defined by MPD. 

B. All traffic will be tail dropped. 

C. Traffic will be dropped with a rate of 1 packet out of 20. 

D. Traffic will be dropped with a rate of 1 packet out of 30. 

Answer:

Q8. An support engineer has been tasked to protect an ISP infrastructure from the growing number of encrypted DDoS attacks. The solution should also validate the eBGP peering. Which solution accomplishes these goals? 

A. BGP FlowSpec 

B. BTSH 

C. BGP Route Dampening 

D. BGP LS 

E. RTBH 

Answer:

Q9. Two Service Providers are beginning a merger between AS boundaries to provide MPLS-enabled services between their networks. Customers are using both Service Providers for services and, under certain circumstances; there are requirements to extend Layer 2 VPN circuits between each provider. The providers are in the process of completing the technical merger. However, the MPLS is not supported between the providers. Which action allows MPLS Layer 2 VPN circuits to be built over the inter-AS link? 

A. Create a GRE tunnel with the mpls ip command between ASBRs. 

B. Create Layer 2 VPN peerings between PE routers from each provider. 

C. Create a VPNv4 peering between ASBRs to advertise labels between each provider. 

D. Create a sham link between ASBR routers to enable a superbackbone peering for Layer 2 VPN signaling. 

Answer:

Explanation: https://ccdewiki.wordpress.com/2013/07/02/inter-as-l2vpn-mpls-solutions/ 

Q10. 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: