400-101 Exam - CCIE Routing and Switching (v5.0)

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Q1. Which two tunneling techniques determine the IPv4 destination address on a per-packet basis? (Choose two.) 

A. 6to4 tunneling 

B. ISATAP tunneling 

C. manual tunneling 

D. GRE tunneling 

Answer: A,B 

Explanation: Tunnel Configuration Parameters by Tunneling Type 

Tunneling Type 

Tunnel Configuration Parameter 

Tunnel Mode 

Tunnel Source 

Tunnel Destination 

Interface Prefix or Address 

Manual 

ipv6ip 

An IPv4 address, or a reference to an interface on which IPv4 is configured. 

An IPv4 address. 

An IPv6 address. 

GRE/IPv4 

gre ip 

An IPv4 address. 

An IPv6 address. 

IPv4-compatible 

ipv6ip auto-tunnel 

Not required. These are all point-to-multipoint tunneling types. The IPv4 destination address is calculated, on a per-packet basis, from the IPv6 destination. 

Not required. The interface address is generated as ::tunnel-source/96. 

6to4 

ipv6ip 6to4 

An IPv6 address. The prefix must embed the tunnel source IPv4 address 

ISATAP 

ipv6ip isatap 

An IPv6 prefix in modified eui-64 format. The IPv6 address is generated from the prefix and the tunnel source IPv4 address. 

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

Q2. DRAG DROP 

Drag and drop each MLPPP command on the left to the function it performs on the right. 

Answer:  

Q3. How does having an EIGRP feasible successor speed up convergence? 

A. EIGRP sends queries only if there is a feasible successor, which decreases the number of routers that are involved in convergence. 

B. EIGRP sends queries only if there is not a feasible successor, which causes less control traffic to compete with data. 

C. EIGRP immediately installs the loop-free alternative path in the RIB. 

D. EIGRP preinstalls the feasible successor in the RIB in all cases, which causes traffic to switch more quickly. 

Answer:

Explanation: 

Feasible Successor 

. A next-hop router that serves as backup to the current successor. 

. The condition is that the said router’s AD (or RD) is less than the FD of the current successor route. 

. Once the feasible successor is selected, they are placed in the topology table. If a change in topology occurs which requires a new route, DUAL looks for the feasible successor and uses it as new route immediately, resulting in fast convergence. 

Reference: http://routemyworld.com/2008/07/page/2/ 

Q4. Which two statements about the protected ports feature and the private VLAN feature are true? (Choose two.) 

A. The protected ports feature is limited to the local switch. 

B. The protected ports feature can isolate traffic between two "protected" ports on different switches. 

C. The private VLAN feature is limited to the local switch. 

D. The private VLAN feature prevents interhost communication within a VLAN across one or more switches. 

Answer: A,D 

Explanation: 

Protected Ports (PVLAN Edge) In some network environments, there is a requirement for no traffic to be seen or forwarded between host(s) on the same LAN segment, thereby preventing interhost communications. The PVLAN edge feature provisions this isolation by creating a firewall-like barrier, thereby blocking any unicast, broadcast, or multicast traffic among the protected ports on the switch. Note that the significance of the protected port feature is limited to the local switch, and there is no provision in the PVLAN edge feature to isolate traffic between two "protected" ports located on different switches. For this purpose, the PVLAN feature can be used. 

Reference: http://www.ciscopress.com/articles/article.asp?p=1181682&seqNum=2 

Q5. Which IP SLA operation type is enhanced by the use of the IP SLAs Responder? 

A. DNS 

B. HTTP 

C. ICMP Echo 

D. UDP Echo 

Answer:

Explanation: 

Figure 1. UDP Echo Operation 

Response time (round-trip time) is computed by measuring the time taken between sending a UDP echo request message from Device B to the destination device--Device A--and receiving a UDP echo reply from Device A. UDP echo accuracy is enhanced by using the IP SLAs Responder at Device A, the destination Cisco device. If the destination device is a Cisco device, then IP SLAs sends a UDP datagram to any port number that you specified. Using the IP SLAs Responder is optional for a UDP echo operation when using Cisco devices. The IP SLAs Responder cannot be configured on non-Cisco devices. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/ipsla/configuration/15-mt/sla-15-mt-book/sla_udp_echo.html 

Q6. Refer to the exhibit. 

Which statement is true? 

A. R2 is directly connected to the receiver for this group and is the winner of an assert mechanism. 

B. R2 is directly connected to the receiver for this group, and it forwards the traffic onto Ethernet3/0, but it is forwarding duplicate traffic onto Ethernet3/0. 

C. R2 has the A flag (Accept flag) set on Ethernet 3/0. This is fine, since the group is in BIDIR-PIM mode. 

D. R2 is directly connected to the receiver for this group and is the loser of an assert mechanism. 

E. The A flag is set until the SPT threshold is reached for this multicast group. 

Answer:

Explanation: 

show ip mroute Field Descriptions 

Field 

Description 

RPF neighbor or RPF nbr 

IP address of the upstream router to the source. Tunneling indicates that this router is sending data to the RP encapsulated in register packets. The hexadecimal number in parentheses indicates to which RP it is registering. Each bit indicates a different RP if multiple RPs per group are used. If an asterisk (*) appears after the IP address in this field, the RPF neighbor has been learned through an assert. 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_2/ipmulti/command/reference/fiprmc_r/1rfmult 3.html 

Q7. A packet capture log indicates that several router solicitation messages were sent from a local host on the IPv6 segment. What is the expected acknowledgment and its usage? 

A. Router acknowledgment messages will be forwarded upstream, where the DHCP server will allocate addresses to the local host. 

B. Routers on the IPv6 segment will respond with an advertisement that provides an external path from the local subnet, as well as certain data, such as prefix discovery. 

C. Duplicate Address Detection will determine if any other local host is using the same IPv6 address for communication with the IPv6 routers on the segment. 

D. All local host traffic will be redirected to the router with the lowest ICMPv6 signature, which is statically defined by the network administrator. 

Answer:

Q8. Refer to the exhibit. 

How can the EIGRP hello and hold time for Gig0/0 be changed to 5 and 15? 

A. No action is required, since Gig0/0 is not listed with a nondefault hello and hold time. 

B. Add the commands ip hello-interval eigrp 1 5 and ip hold-time eigrp 1 15 under interface Gig0/0. 

C. Add the commands hello-interval 5 and hold-time 15 under "af-interface Gig0/0" under the address family. 

D. Add the commands default hello-interval and default hold-time under the af-interface Gig0/0 statement under the address family. 

Answer:

Explanation: 

To configure the hello interval for an interface, use the hello-interval command in interface configuration mode To configure the hold time for an interface, use the hold-time command in interface configuration mode. 

Reference: http://www.cisco.com/c/en/us/td/docs/routers/crs/software/crs_r4-1/routing/command/reference/b_routing_cr41crs/b_routing_cr41crs_chapter_010.html#wp2 323069468 

Q9. In an STP domain, which two statements are true for a nonroot switch, when it receives a configuration BPDU from the root bridge with the TC bit set? (Choose two.) 

A. It sets the MAC table aging time to max_age time. 

B. It sets the MAC table aging time to forward_delay time. 

C. It recalculates the STP topology upon receiving topology change notification from the root switch. 

D. It does not recalculate the STP topology upon receiving topology change notification from the root switch. 

Answer: B,D 

Q10. Assume that the following MAC addresses are used for the bridge ID MAC address by four different switches in a network. Which switch will be elected as the spanning-tree root bridge? 

A. SwitchA uses MAC 1000.AA-AA-AA-AA-AA-AA. 

B. SwitchB uses MAC 2000.BB-BB-BB-BB-BB-BB. 

C. SwitchC uses MAC 3000.CC-CC-CC-CC-CC-CC. 

D. SwitchD uses MAC 4000.DD-DD-DD-DD-DD-DD. 

Answer:

Explanation: 

The switch with the highest switch priority (the lowest numerical priority value) is elected as the root switch. If all switches are configured with the default priority (32768), the switch with the lowest MAC address in the VLAN becomes the root switch. 

Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12-2_53_se/configuration/guide/2960scg/swstp.html