Exam Code: 400-101 (Practice Exam Latest Test Questions VCE PDF)
Exam Name: CCIE Routing and Switching (v5.0)
Certification Provider: Cisco
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Q51. DRAG DROP 

Drag each traceroute text character on the left to its meaning on the right. 

Answer: 


Q52. Which TCP feature allows a client to request a specific packet that was lost? 

A. flow control 

B. sliding window 

C. fast recovery 

D. selective acknowledgment 

Answer:

Explanation: 

. TCP Selective Acknowledgment 

The TCP Selective Acknowledgment feature improves performance if multiple packets are lost from one TCP window of data. Prior to this feature, because of limited information available from cumulative acknowledgments, a TCP sender could learn about only one lost packet per-round-trip time. An aggressive sender could choose to resend packets early, but such re-sent segments might have already been successfully received. The TCP selective acknowledgment mechanism helps improve performance. The receiving TCP host returns selective acknowledgment packets to the sender, informing the sender of data that has been received. In other words, the receiver can acknowledge packets received out of order. The sender can then resend only missing data segments (instead of everything since the first missing packet). Prior to selective acknowledgment, if TCP lost packets 4 and 7 out of an 8-packet window, TCP would receive acknowledgment of only packets 1, 2, and 3. Packets 4 through 8 would need to be re-sent. With selective acknowledgment, TCP receives acknowledgment of packets 1, 2, 3, 5, 6, and 8. Only packets 4 and 7 must be re-sent. TCP selective acknowledgment is used only when multiple packets are dropped within one TCP window. There is no performance impact when the feature is enabled but not used. Use the ip tcp selective-ack command in global configuration mode to enable TCP selective acknowledgment. 

Refer to RFC 2021 for more details about TCP selective acknowledgment. 


Q53. Which three actions are required when configuring NAT-PT? (Choose three.) 

A. Enable NAT-PT globally. 

B. Specify an IPv4-to-IPv6 translation. 

C. Specify an IPv6-to-IPv4 translation. 

D. Specify a ::/96 prefix that will map to an IPv4 address. 

E. Specify a ::/48 prefix that will map to a MAC address. 

F. Specify a ::/32 prefix that will map to an IPv6 address. 

Answer: B,C,D 

Explanation: 

The detailed steps on configuring NAY-PT is found at the reference link below: 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/ipv6/configuration/guide/12_4t/ipv6_12_4t_book/i p6-nat_trnsln.html 


Q54. Which three statements about IS-IS are true? (Choose three.) 

A. IS-IS is not encapsulated in IP. 

B. IS-IS is directly encapsulated in the data link layer. 

C. 0XFEFE is used in the Layer 2 header to identify the Layer 3 protocol. 

D. IS-IS uses protocol ID 93. 

E. IS-IS can be used to route the IPX protocol. 

F. IS-IS is an IETF standard. 

Answer: A,B,C 

Explanation: 

IS-IS is an Interior Gateway Protocol (IGP) for routing OSI. IS-IS packets are not encapsulated in CLNS or IP but are encapsulated directly in the data-link layer. The IS-IS protocol family is OSI, and values such as 0xFE and 0xFEFE are used by the data-link protocol to identify the Layer 3 protocol as OSI. 

Reference: http://www.cisco.com/en/US/products/ps6599/products_white_paper09186a00800a3e6f.sh tml 


Q55. DRAG DROP 

Drag each show command on the left to the description of its output on a PE router on the right. 

Answer: 


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Q56. Which two actions can you take to allow the greatest number of pertinent packets to be stored in the temporary buffer of Cisco IOS Embedded Packet Capture? (Choose two.) 

A. Specify the sampling interval. 

B. Specify the capture buffer type. 

C. Specify a reflexive ACL. 

D. Specify the minimum packet capture rate. 

E. Specify the packet size. 

F. Store the capture simultaneously onto an external memory card as the capture occurs. 

Answer: A,B 

Explanation: 

Embedded Packet Capture (EPC) provides an embedded systems management facility that helps in tracing and troubleshooting packets. This feature allows network administrators to capture data packets flowing through, to, and from a Cisco device. The network administrator may define the capture buffer size and type (circular, or linear) and the maximum number of bytes of each packet to capture. The packet capture rate can be throttled using further administrative controls. For example, options allow for filtering the packets to be captured using an Access Control List and, optionally, further defined by specifying a maximum packet capture rate or by specifying a sampling interval. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/epc/configuration/xe-3s/asr1000/epc-xe-3s-asr1000-book/nm-packet-capture-xe.html 


Q57. Which statement describes the native VLAN concept in an ISL trunk? 

A. It is the VLAN ID that is assigned to untagged packets. 

B. It is the VLAN with highest priority. 

C. It is the default VLAN for a trunk. 

D. There is no native VLAN concept in an ISL trunk. 

Answer:

Explanation: 

ISL has no native VLAN concept because it places the entire Ethernet frame in the payload of an ISL frame. Native VLANs is an 802.1Q specific concept 


Q58. Which two statements about GLBP are true? (Choose two.) 

A. Packets are forwarded by multiple routers that share one virtual IP address. 

B. The active router forwards packets received on one virtual IP and MAC address. 

C. The standby router forwards packets when the active router fails. 

D. Hosts on the network are configured with multiple gateways for load balancing. 

E. Routers in a GLBP group can share multiple virtual MAC addresses. 

Answer: A,E 


Q59. Which two options are reasons to manipulate the delay metric instead of the bandwidth metric for EIGRP routing? (Choose two.) 

A. Because the delay metric provides better handling for bursty traffic 

B. Because manipulating the bandwidth metric can also affect QoS 

C. Because manipulating the bandwidth affects only a particular path 

D. Because changes to the delay metric are propagated to all neighbors on a segment 

Answer: B,D 

Explanation: 

Using the bandwidth to influence EIGRP paths is discouraged for two reasons: 

. Changing the bandwidth can have impact beyond affecting the EIGRP metrics. For example, quality of service (QoS) also looks at the bandwidth on an interface. 

. EIGRP throttles to use 50 percent of the configured bandwidth. Lowering the bandwidth can cause problems like staving EIGRP neighbors from getting hello packets because of the throttling back. 

Because changes to the delay metric are propagated to all downstream routers, changing the interface delay parameter is the preferred method of influencing path selection 

Reference: http://www.cisco.com/c/en/us/support/docs/ip/enhanced-interior-gateway-routing-protocol-eigrp/13673-14.html 


Q60. Refer to the exhibit. 

You have just created a new VRF on PE3. You have enabled debug ip bgp vpnv4 unicast updates on PE1, and you can see the route in the debug, but not in the BGP VPNv4 table. 

Which two statements are true? (Choose two.) 

A. VPNv4 is not configured between PE1 and PE3. 

B. address-family ipv4 vrf is not configured on PE3. 

C. After you configure route-target import 999:999 for a VRF on PE3, the route will be accepted. 

D. PE1 will reject the route due to automatic route filtering. 

E. After you configure route-target import 999:999 for a VRF on PE1, the route will be accepted. 

Answer: D,E 

Explanation: 

The route target extended community for VPLS auto-discovery defines the import and export policies that a VPLS instance uses. The export route target sets an extended community attribute number that is appended to all routes that are exported from the VPLS instance. The import route target value sets a filter that determines the routes that are accepted into the VPLS instance. Any route with a value in its import route target contained in its extended attributes field matching the value in the VPLS instance’s import route target are accepted. Otherwise the route is rejected.