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

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Q1. Refer to the exhibit. 

Which two possible network conditions can you infer from this configuration? (Choose two.) 

A. The authentication parameters on R1 and R2 are mismatched. 

B. R1 is using the default NTP source configuration. 

C. R1 and R2 have established an NTP session. 

D. R2 is configured as the NTP master with a stratum of 7. 

Answer: A,B 

Explanation: 

Answer A. The NTP associations are not synced, it is only listed as a candidate because it was configured. Routing is not the issue, so it must be mismatched authentication parameters. 

Answer B. NTP sets the source IP address for all NTP packets based on the address of the interface through which the NTP packets are sent. You can configure NTP to use a specific source IP address. 

Q2. What are two reasons to use the ip ospf database filter all out command? (Choose two.) 

A. to maintain a centralized OSPF database on a single master device 

B. to avoid flooding LSAs on low-speed links 

C. to ensure a consistent OSPF database across the network 

D. to selectively filter OSPF routes without disrupting the SPF algorithm 

E. to filter only type 7 LSAs from an OSPF area 

F. to enable OSPF to send triggered updates 

Answer: A,B 

Q3. Which technology can create a filter for an embedded packet capture? 

A. Control plane policing 

B. Access lists 

C. NBAR 

D. Traffic shaping 

Answer:

Explanation: 

A filter can be applied to limit the capture to desired traffic. Define an Access Control List (ACL) within config mode and apply the filter to the buffer: 

ip access-list extended BUF-FILTER 

permit ip host 192.168.1.1 host 172.16.1.1 

permit ip host 172.16.1.1 host 192.168.1.1 

monitor capture buffer BUF filter access-list BUF-FILTER 

Reference: http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-embedded-packet-capture/116045-productconfig-epc-00.html 

Q4. Which regular expression will match prefixes that originated from AS200? 

A. ^$ 

B. ^200_ 

C. _200$ D. ^200) 

E. _200_ 

Answer:

Explanation: 

Example on how to deny all prefixes originated in Autonomous System 200 

router bgp 100 

neighbor 10.1.1.1 remote-as 65535 

neighbor 10.1.1.1 route-map map1 in 

route-map map1 permit 10 

match as-path 1 

ip as-path access-list 5 deny _200$ 

ip as-path access-list 5 permit .* 

Reference: http://www.cisco.com/c/en/us/td/docs/ios/termserv/configuration/guide/12_4t/tsv_12_4t_bo ok/tsv_reg_express.html 

Q5. Which two BGP path attributes are visible in Wireshark? (Choose two.) 

A. weight 

B. AS path 

C. local preference 

D. route maps 

Answer: B,C 

Q6. Which statement is true comparing L2TPv3 to EoMPLS? 

A. L2TPv3 requires OSPF routing, whereas EoMPLS does not. 

B. EoMPLS requires BGP routing, whereas L2TPv3 does not. 

C. L2TPv3 carries L2 frames inside MPLS tagged packets, whereas EoMPLS carries L2 frames inside IPv4 packets. 

D. L2TPv3 carries L2 frames inside IPv4 packets, whereas EoMPLS carries L2 frames inside MPLS packets. 

Answer:

Explanation: 

Ethernet-over-MPLS (EoMPLS) provides a tunneling mechanism for Ethernet traffic through an MPLS-enabled L3 core and encapsulates Ethernet protocol data units (PDUs) inside MPLS packets (using label stacking) to forward them across the MPLS network. Another technology that more or less achieves the result of AToM is L2TPV3. In the case of L2TPV3 Layer 2 frames are encapsulated into an IP packet instead of a labelled MPLS packet. 

Reference: http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-3/lxvpn/configuration/guide/lesc43xbook/lesc43p2ps.html 

Q7. Which two configuration changes should be made on the OTP interface of an EIGRP OTP route reflector? (Choose two.) 

A. passive-interface 

B. no split-horizon 

C. no next-hop-self 

D. hello-interval 60, hold-time 180 

Answer: B,C 

Explanation: 

The EIGRP Over the Top feature enables a single end-to-end Enhanced Interior Gateway Routing Protocol (EIGRP) routing domain that is transparent to the underlying public or private WAN transport that is used for connecting disparate EIGRP customer sites. When an enterprise extends its connectivity across multiple sites through a private or a public WAN connection, the service provider mandates that the enterprise use an additional routing protocol, typically the Border Gateway Protocol (BGP), over the WAN links to ensure end-to-end routing. The use of an additional protocol causes additional complexities for the enterprise, such as additional routing processes and sustained interaction between EIGRP and the routing protocol to ensure connectivity, for the enterprise. With the EIGRP Over the Top feature, routing is consolidated into a single protocol (EIGRP) across the WAN. 

Perform this task to configure a customer edge (CE) device in a network to function as an EIGRP Route Reflector: 

1. enable 

2. configure terminal 

3. router eigrp virtual-name 

4. address-family ipv4 unicast autonomous-system as-number 

5. af-interface interface-type interface-number 

6. no next-hop-self 

7. no split-horizon 

8. exit 

9. remote-neighbors source interface-type interface-number unicast-listen lisp-encap 

10. network ip-address 

11. end 

Note. Use no next-hop-self to instruct EIGRP to use the received next hop and not the local outbound interface address as the next hop to be advertised to neighboring devices. If no next-hop-self is not configured, the data traffic will flow through the EIGRP Route Reflector. 

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 

Q8. Refer to the exhibit. 

Which two statements about the implementation are true? (Choose two.) 

A. The PPP multilink protocol header is omitted on delay-sensitive packets. 

B. The maximum number of fragments is 1. 

C. Small real-time packets are multilink-encapsulated. 

D. A transmit queue is provided for smaller packets. 

Answer: A,D 

Explanation: 

Previous implementations of Cisco IOS Multilink PPP (MLP) include support for Link Fragmentation Interleaving (LFI). This feature allows the delivery of delay-sensitive packets, such as the packets of a Voice call, to be expedited by omitting the PPP Multilink Protocol header and sending the packets as raw PPP packets in between the fragments of larger data packets. This feature works well on bundles consisting of a single link. However, when the bundle contains multiple links there is no way to keep the interleaved packets in sequence with respect to each other. The Multiclass Multilink PPP (MCMP) feature in Cisco IOS Release 12.2(13)T addresses the limitations of MLP LFI on bundles containing multiple links by introducing multiple data classes. With multiclass multilink PPP interleaving, large packets can be multilink-encapsulated and fragmented into smaller packets to satisfy the delay requirements of real-time voice traffic; small real-time packets, which are not multilink encapsulated, are transmitted between fragments of the large packets. The interleaving feature also provides a special transmit queue for the smaller, delay-sensitive packets, enabling them to be transmitted earlier than other flows. Interleaving provides the delay bounds for delay-sensitive voice packets on a slow link that is used for other best-effort traffic. 

References: http://www.cisco.com/c/en/us/td/docs/ios/dial/configuration/guide/12_4t/dia_12_4t_book/dia _multiclass_link_ppp.pdf http://www.cisco.com/c/en/us/td/docs/routers/access/500/520/software/configuration/guide/520_SCG_Book/520scg_concepts.html 

Q9. Which two statements about PBR route maps are true? (Choose two.) 

A. They can use extended ACLs to identify traffic. 

B. They can route unicast traffic without interface-level classification. 

C. They can be applied to both ingress and egress traffic. 

D. They can classify traffic based on prefix-lists. 

E. They can set the metric and IP precedence bits. 

Answer: A,B 

Q10. Which protocol will accept incoming updates when the passive-interface command is configured? 

A. OSPF 

B. IS-IS 

C. RIP 

D. EIGRP 

Answer: