Cisco.Cerifyme-ActualTests by.DD.89Q

Transcription

1 Cisco.Cerifyme-ActualTests by.DD.89Q Number: Passing Score: 800 Time Limit: 120 min File Version: CertifyMe and

2 Exam A QUESTION 1 Refer to the exhibit. The customer has an MPLS Layer 3 VPN service CE-A is not able to ping the CE-B loopback address CE-A is able to ping the CE-B network interface address What must be added to the configuration to allow the loopback ping to work? A. The PE-B configuration needs a neighbor command added B. The PE-B configuration needs interface loopback0 added under vrf red area 0 C. The CE-B configuration needs to static route added for the PE-B connected interface D. The CE-B configuration needs network under router ospf 1 Correct Answer: D

3 QUESTION 2 Refer to the exhibit. Build Your Dreams PassGuide What type of MPLS LAYER 3 VPN configurations is represented? A. Simple two-vpn scenario

4 B. Overlapping VPNs C. Central services VPNs D. Extranet VPNs Correct Answer: C

5 QUESTION 3 In a Service Provider Layer 3 MPLS VPN implementation, what is the minimum number of routing or distribution protocols running on the PE routers? A. Three B. Four C. Five D. Six Correct Answer: A BGP - gives us MP-BGP also MPLS PE IGP QUESTION 4 Refer to the exhibit. Build Your Dreams PassGuide

6 The commands on the figure were executed from a cisco ASR 9000 series router. The remote end of ping is cisco XR series router. Which statement is true? A. The XR has an access list that blacks the MPLS pseudowire ping B. The interface connected to the XR is not running LDP C. These results will occur during convergence when MPLS LDP sync is enabled D. The MPLS pseudowire ping was not sent Correct Answer: D QUESTION 5 Refer to the exhibit. Build Your Dreams PassGuide

7 The output from the debug command is from the Cisco XR12000 series Router, which statement is true? A. The output is the result of single iteration of mpls ping executed on the cisco ASR 9000 Series Router' B. The output is the result of single iteration of mpls ping executed on the cisco ASR 9000 series Router C. The packets did not reach its destination because the control word was not found D. The output is the result of single iteration of mpls ping executed on the cisco CRS-1 carrier routing system. Correct Answer: C

8 QUESTION 6 Refer to the exhibit. Build Your Dreams PassGuide The commands were exceeded on the cisco XR PE. Which statement is true? A. The outer label for prefix is B. The outer label for prefix is C. The outer label for prefix is implnull. D. Prefix has no outer label.

9 Correct Answer: A no local label so : QUESTION 7 You have configured a MPLS-TE tunnel with a predefined explicit path as primary and dynamic path as the backup. The tunnel was designed to carry customer traffic from site A to site B. although the MPLS-TE tunnel is set up. It is not carrying the traffic. Traffic has to go to net work /16 connected to site B. Which three show commands would you use to identify and resolve the issue? A. Show mpls traffic-eng-link-management bandwidth to check the bandwidth is available. B. Show ip cef network-number to check if tags are imposed C. Show mpls traffic-eng topology ipg-id ospf network number brief to check routing issue D. Show mpls traffic-eng autoroute to check auto routing is enabled E. Show mpls forwarding-table LABEL-number details to outgoing tags F. Show ip cef tunnel 1 to check traffic is passing through the tunnel Correct Answer: BDF

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11 QUESTION 8 Refer to the exhibit. Build Your Dreams PassGuide Is nonstop forwarding enabled or disabled, and which part of show command can be used to determine this? A. Enabled, graceful-restart B. Enabled, session protection C. Disabled, graceful-restart D. Disabled, session protection Correct Answer: A QUESTION 9 Refer to the exhibit.

12 What two problems are associated with this show MPLS forwarding command output; given that this command only shows forwarding information for CEs interfaces and associated statistics? (Choose two) A. Line 1 and 3 indicate the problem B. Line 2 and 4 indicate the problem C. LDP is not active on AT 12/ and se 9/0/7.0 that is why packets are sent as IP packets and no MPLS packets D. There is a possible routing loop which makes pe-1 a transit router for the VRFs which are assigned to Gi 14/.1271 and AT 12/ E. There is label corruption for VRFs where Gi 14/ and AT 12/ belong to, the value of a locally assigned label cannot be more than the value of outgoing label Correct Answer: BE Original answer was B/E - I think A for sure and probably C are correct

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14 QUESTION 10 Build Your Dreams PassGuide You have been assigned the task of collecting the relevant information for trouble shooting a Layer 3 MPLS

15 VPN routing issue across two (same VPN) for a customer. After initial diagnostics you have ruled out any connectivity issues and any hardware or software bugs. Which four steps should you use to collect information for troubleshooting the VPN routing issue? (Choose four) A. Redistribution of routes into MP-BGP B. Route fillers that might prevent routes from propagating C. Interface state between PE and CE devices D. VRF route target import and export details E. MPLS forwarding state between PE and core routers F. VRF route limit on the PE devices G. Interface error counters on the customer-facing PE interface Correct Answer: ABDE QUESTION 11 Which three MPLS services require MPLS layer 2 VPNs? (Choose three) A. Any-to-any interworking B. Central services VPN C. VPLS D. VPWS Correct Answer: ACD

16 QUESTION 12 A service provider is running OSPF and has turned the network for fast convergence. The service provider has determined that its routers should also be configured for LDP synchronization. If the service provider follows ITIL-based practices, how should this change be treated? A. As a standard change B. As a minor change C. As a major change D. As an emergency change

17 Correct Answer: D QUESTION 13 What are three basic functional requirements when configuring MPLS layer 2 VPLS? (Choose three) A. A CE to PE routing protocol must be used to exchange routing prefixes Build Your Dreams PassGuide B. A full mesh of pseudowire (emulated VC) connections must be used between PE routers C. Each PE must have a VFI configured D. LDP protocol must be running E. Auto discovery is needed to identify endpoints outside of the VPLS domain. Correct Answer: BCD Before you configure VPLS, ensure that the network is configured as follows: Configure IP routing in the core so that the PE routers can reach each other via IP. Configure MPLS in the core so that a label switched path (LSP) exists between the PE routers. Configure a loopback interface for originating and terminating Layer 2 traffic. Make sure the PE routers can access the other router's loopback interface. Note that the loopback interface is not needed in all cases. For example, tunnel selection does not need a loopback interface when VPLS is directly mapped to a TE tunnel. VPLS configuration requires you to identify peer PE routers and to attach Layer 2 circuits to the VPLS at each PE router. The full-mesh configuration requires a full mesh of tunnel label switched paths (LSPs) between all the PEs that participate in the VPLS. With full-mesh, signaling overhead and packet replication requirements for each provisioned VC on a PE can be high. You set up a VPLS by first creating a virtual forwarding instance (VFI) on each participating PE router. The VFI specifies the VPN ID of a VPLS domain, the addresses of other PE routers in the domain, and the type of tunnel signaling and encapsulation mechanism for each peer PE router. The set of VFIs formed by the interconnection of the emulated VCs is called a VPLS instance; it is the VPLS instance that forms the logic bridge over a packet switched network. The VPLS instance is assigned a unique VPN ID. The PE routers use the VFI to establish a full-mesh LSP of emulated VCs to all the other PE routers in the VPLS instance. PE routers obtain the membership of a VPLS instance through static configuration using the Cisco IOS CLI. The full-mesh configuration allows the PE router to maintain a single broadcast domain. Thus, when the PE router receives a broadcast, multicast, or unknown unicast packet on an attachment circuit, it sends the packet out on all other attachment circuits and emulated circuits to all other CE devices participating in that VPLS instance. The CE devices see the VPLS instance as an emulated LAN. To avoid the problem of a packet looping in the provider core, the PE devices enforce a "split-horizon" principle for the emulated VCs. That means if a packet is received on an emulated VC, it is not forwarded on any other emulated VC. After the VFI has been defined, it needs to be bound to an attachment circuit to the CE device. The packet forwarding decision is made by looking up the Layer 2 virtual forwarding instance (VFI) of a particular VPLS domain. QUESTION 14 Refer to the exhibit.

18 Which statement about the two show command is true> A. The CE-PE routing protocol between the PE and customer_1 CE router is BGP B. The PE router ha learned four prefixes over the multiprotocol BGP session C is CE router and is the PE router D. The PE router is supporting more than one MPLS layer 3 VPN customers Correct Answer: B

19 QUESTION 15 What are four essential parts of the MP-BGP VPNv4 update? (Choose four) A. LDP label B. VPN label Build Your Dreams PassGuide C. IPv4 prefix with route descriptor D. LSP identifier E. BGP next-hop address F. Route targets (extended communities) Correct Answer: BCEF QUESTION 16 What function does MP-BGP provides that is required for MPLS layer 3 VPM services? A. MP-BGP modifies or swaps the LDP label to indicate the next-hop router in MPLS cloud B. MP-BGP provides the penultimate hop popping function C. MP-BGP performs the standard MPLS LDP functions in layer 3 environment D. MP-BGP advertises the VPN label and identifies the correct egress PE interface Correct Answer: D

20 QUESTION 17 Refer to the exhibit. A layer 3 VPN is configured between PE1 and PE2. CE1 is connected to PE1. CE2 is Build Your Dreams PassGuide connected to PE2. CE1 and CE2 are in VRF red. From which router does the prefix /24 originates? A. CE1 B. PE1 C. PE2 D. CE2 Correct Answer: A

21 QUESTION 18 A cisco 7600 series Router is experiencing high CPU utilization and poor forwarding performance. Investigation reveals that packet forwarding has been punted to the RP. What are two possible causes of this behavior? (Choose two) A. The routing table is too large B. Liberal retention mode has been disabled C. An insufficient number of flow masks are configured D. A large number of access list entries are configured E. IGP timers need to be returned to improve routing convergence Correct Answer: BD Label Allocation Modes The label allocation mode refers to which of a given pair of LSRs will be allocating the labels that will be used on traffic sent from one to the other. For a given stream of data, the LSR that is required to interpret the label on packets in the stream received from the other LSR is the downstream LSR. The LSR that puts the label on packets in the stream that it sends to another LSR is the upstream LSR. Downstream Label Allocation

22 Downstream label allocation is the only mode currently defined for MPLS. Using this approach allows for a minimal amount of label negotiation because the LSR that is required to interpret labels is responsible for assigning them. Upstream Label Allocation Upstream label allocation is not a supported mode in the current version of MPLS. The advantage associated with this label allocation mode is that switching hardware could realize significant gains from being able to use the same label on a number of different interfaces for multicast traffic. Label Distribution Modes This section describes MPLS modes specific to distributing MPLS labels. Downstream On-Demand Label Distribution In downstream on-demand mode, label mappings are provided to an upstream LSR when requested. Because labels will not usually be requested unless needed for an NHLFE, this approach results in substantially less label-release traffic for unwanted labels when conservative label retention is in use and when the number of candidate interfaces that will not be used for a next hop is relatively large. All LSRs must be able to provide labels when requested because (in the case where an LSR is not merge capable) the upstream LSR will need as many labels for LSPs going downstream as it has LSPs arriving at it from upstream. There is no standard way that a downstream LSR would know in advance how many labels to provide to an upstream peer; hence, the downstream LSR must be able to provide new labels as requested. In addition, even an LSR that relies for the most part on downstream unsolicited label distribution will from time to time need to obtain a label that it released earlier. This is true because whether the LSR uses conservative or liberal retention mode (described later) the LSR may release labels it is unlikely to use given a particular routing topology. If the topology changes in a significant way (for instance, the routed path for some streams is reversed from what it was earlier), these labels will be suddenly and (possibly) unexpectedly needed. Thus, the basic capabilities associated with downstream on-demand distribution must be present regardless of the dominant mode used by an LSR. Downstream Unsolicited Label Distribution In downstream unsolicited mode, label mappings are provided to all peers for which the local LSR might be a next hop for a given FEC.23 This would typically be done at least once during the lifetime of a peer relationship between adjacent LSRs. Label Retention Modes Label retention mode refers to the way in which an LSR treats label mappings it is not currently using. Note that the label retention mode may be particularly uninteresting when the downstream on-demand label distribution mode is in use. Conservative Label Retention In the conservative label retention mode, any label mapping received from a peer LSR that is not used in an active NHLFE is released. The advantage of this mode is that only labels that will be used given the existing topology are retained, reducing the amount of memory consumed in retaining labels. The potential cost is delay in obtaining new labels when a topology change occurs. When this mode is combined with downstream on-demand label distribution (as is most likely the case), the number of labels distributed from adjacent peers will be fewer as well. Liberal Label Retention In the liberal label retention mode, any label mapping that may ever be used as part of an active NHLFE is retained up to and including all label mappings received. The advantage of this mode is that should a topology change occur, the labels to use in the new topology are usually already in place. This advantage is realized at the price of storing labels that are not in use. For labelswitching devices that have large numbers of ports, this memory cost can be very high because the likelihood that any particular label will be used to forward packets out of any particular port is, in general, inversely proportional to the total number of ports. Interaction between Label Distribution and Retention Modes The interaction between label distribution and retention is such that conservative retention is a more natural fit for downstream on-demand distribution, whereas liberal retention is a more natural fit for downstream unsolicited distribution. The reason is the need to send messages to release unused labels in both distribution modes and to specifically request labels in downstream on-demand distribution. In the conservative retention mode, it does not make sense to get unsolicited labels because most of these will subsequently be released. For label-switching devices with many peers, the amount of message traffic associated with releasing unwanted labels (received as a result of downstream unsolicited distribution) after each routing change will typically be many times the number of messages required to request and receive labels using downstream on-demand distribution. In the liberal retention mode, it does not make sense to use downstream on-demand distribution because of the

23 need to specifically request labels for all FECs from all peers. If liberal retention is to be used, downstream unsolicited distribution mode effectively eliminates half of the message traffic otherwise required. However, as implied earlier, when downstream on-demand distribution is used, it is arguable that liberal retention is also used, since all label mappings received from peers are retained. The spirit of liberal retention is to retain labels for all peers at least one label from each peer and for each FEC. To achieve this using downstream on-demand distribution is clearly a suboptimal approach. Control Modes The distinction between the ordered and independent control modes is, in practice, likely to be a lot less than people have made it out to be in theory. With specific exceptions (for instance, traffic engineering tunnels, discussed later), choice of control mode is local rather than network wide. In addition, certain behaviors associated with a strict interpretation of control mode can result in pathological misbehavior within the network. Ordered Control Mode In ordered control mode, LSP setup is initiated at one point and propagates from there toward a termination point. In the case where LSP setup is initiated at an ingress, label requests are propagated all the way to an egress; label mappings are then returned until a label mapping arrives at the ingress. In the case where LSP setup is initiated at an egress, label mappings are propagated all the way to ingress points. A feature of ordered control is that an LSP is not completely set up until the associated messages have propagated from end to end hence, data is not sent on the LSP until it is known to be loop free. A severe disadvantage shows up in a purist implementation of ordered control mode in the following case. Assume that an LSR is the egress for a (potentially large) set of LSPs. This LSR now discovers a new peer that is downstream of it with respect to some or all of the set of LSPs for which the LSR is the current egress. If the local LSR simply adds the new LSR as an egress without somehow ascertaining that this LSR does not carry the LSP into a merge point upstream of the local LSR, it may introduce a loop into an LSP assumed to be loop free. If, on the other hand, it withdraws all label mappings upstream, it may produce a significant network outage and will result in a lot of LSP control activity, both of which might be unnecessary. For example, in the case where a downstream routing peer has just had MPLS enabled but is otherwise the same as it was previously, it is unlikely that forwarding will actually change. One way to get around this problem is if the ordered-control LSR continues forwarding as before while it waits for label mappings (assuming it is getting downstream unsolicited label distributions) with a known (nonzero) hop count. In this way, the local LSR can continue to forward packets, using IP forwarding, to the routing peer to which it was forwarding previously.24 Waiting to receive a known hop count for a new LSP that is being established is one way for an intermediate LSR to use ordered control to force ordered control for a portion of the LSP. The fact that the LSP has been established for LSRs downstream is irrelevant if the LSP is not established to an ingress LSR, since no packets will be forwarded on that LSP until the LSP is established to an ingress LSR (by definition, packets are inserted on an LSP at ingress LSRs). Because this behavior prevents an LSP from being established between the local LSR and its upstream neighbors, the local LSR has succeeded in forcing ordered control on the LSP downstream and for at least the one hop to its upstream peers when one or more LSRs between that LSR and an egress are otherwise using independent control. If an LSR continues to forward packets using IP (acting as the egress for a set of LSPs) even though it has discovered another LSR that should be the egress (for that set of LSPs), it is behaving as if it were using independent control at least temporarily in spite of the fact that it may be configured to use ordered control. Independent Control Mode Independent control mode is the mode in use when an LSR Has reason to believe that it will get label mappings from downstream peers for a specific FEC Distributes labels for that FEC to its upstream peers irrespective of whether it has received the expected label mappings from downstream In this case, the LSR sending the label mapping includes a hop count that reflects the fact that it is not the egress and has not received label mappings (directly or indirectly) from an LSR that is. The special hop-count value of zero (unknown hop count) is used to indicate this case. Upstream LSRs may or may not start to use the label mappings thus provided. Using the LSP is probably not advisable, because the LSR providing the label mapping may elect to discard packets (while waiting to receive label mappings from downstream peers), and the LSP is not proven to be loop free (until a label mapping is propagated from downstream with a known hop count). In effect, if an LSP is never used until a label mapping for the LSP containing a known hop count is received at the ingress to the LSP, the network is behaving as if ordered control were in use for all LSRs along the given LSP. Label Spaces Label space refers to the scope of a label within a specific LSR and how this scope relates to an adjacent LSR peer. A label space is designated either per interface or per platform (Figure 4.4). Selection of the label space

24 used for any interface is a configuration or implementation choice. In implementations, either per-interface or per-platform label space may be supported; however, no implementation is required to support both. 25 Figure 4.4 Per-platform label space. With per-platform labels, packets may be forwarded using either of these two links using the same labels. With per-interface labels, this is not guaranteed. The following general statements can be made about LSR implementations: ATM LSRs will most likely not support a per-platform label space. This is true because of the implications of assigning the same VPI/VCI meaning to all ATM interfaces. Support for the per-platform interface is easily achievable using generic MPLS labels (as is the case for PPP or LAN encapsulation, or label stacking). It is possible for per-platform label space to apply to some interfaces and not to others. Otherwise, the presence of a single ATM interface (or a diversity of interfaces) would preclude use of the per-platform label space. The interpretation of "per platform" is only required to be consistent for any implementation with respect to a single peer LSR instance. Thus, rules regarding interpretation of labels distributed to a single LSR peer instance do not necessarily apply to labels distributed to another peer instance, even when both peers are using the per-platform label space.26 A per-interface label space applies when the same label may be interpreted differently at a given interface than it would be at other interfaces, even when these interfaces are in common with the same LSR peer instance. This situation would be likely for ATM or Frame Relay interfaces of an LSR. A per-platform label space applies when the same label will be interpreted the same way at least for all interfaces in common with a peer LSR. An LSR may be able to support multiple per-platform label spaces as long as it is able to ensure that it does not attempt to do so in a way that is visible to any peer LSR instance. In other words, an LSR can advertise two disjoint label spaces as "per-platform" to two different LSR peers and assign and interpret labels accordingly as long as the local LSR can be certain that they are distinct peers. An LSR may not be able to support multiple per-platform label spaces if it is not possible to determine which interfaces are in common with each peer LSR. To understand use of the per-platform label space, it is necessary to understand the motivation for defining it. Interpretation of labels in the per- interface case means matching the incoming interface and the label to determine the outgoing interface, label, and so on. In theory, at least, the per-platform label space allows the implementation to perform a match based on the label alone. In practice, this may not be an acceptable behavior. For one thing, it allows labels received on an interface to direct labeled packets out the same interface (an exceptionally pathological behavior). For another, it allows an LSR to use labels (and associated resources) it was not intended to use. Another possible motivation for use of a per-platform label space is to avoid the necessity of advertising multiple labels for interfaces in common between a pair of LSRs. In this case, however, it is only necessary that labels be shared for interfaces in common. In some implementation architectures, this can easily be done. QUESTION 19 What two mechanisms are used to improve both MPLS network performance and availability? (Choose two) A. LDP and IGP synchronization B. Stateful switchover with fast Reroute C. Stateful switchover D. BGP timer tuning E. Stateful switchover with NSR Correct Answer: AB One version shows D/E as the answers Fast Reroute (FRR) is a mechanism for protecting MPLS TE LSPs from link and node failures by locally repairing the LSPs at the point of failure, allowing data to continue to flow on them while their headend routers try to establish new end-to-end LSPs to replace them. FRR locally repairs the protected LSPs by rerouting them over backup tunnels that bypass failed links or node. Packet loss can occur because the actions of the IGP and LDP are not synchronized. Packet loss can occur in

25 the following situations: When an IGP adjacency is established, the router begins forwarding packets using the new adjacency before the LDP label exchange completes between the peers on that link. If an LDP session closes, the router continues to forward traffic using the link that is associated with the LDP peer rather than an alternate pathway with a fully synchronized LDP session. The MPLS LDP-IGP Synchronization feature does the following: Provides a means to synchronize LDP and IGPs to minimize Multiprotocol Label Switching (MPLS) packet loss. Enables you to globally enable LDP-IGP synchronization on each interface that is associated with an IGP OSPF or IS-IS process. Provides a means to disable LDP-IGP synchronization on interfaces that you do not want enabled. Prevents MPLS packet loss due to synchronization conflicts. Works when LDP is enabled on interfaces using either the mpls ip or mpls ldp autoconfig command. To enable LDP-IGP synchronization on each interface that belongs to an OSPF or IS-IS process, enter the mpls ldp sync command. If you do not want some of the interfaces to have LDP-IGP synchronization enabled, issue the no mpls ldp igp sync command on those interfaces. If the LDP peer is reachable, the IGP waits indefinitely (by default) for synchronization to be achieved. To limit the length of time the IGP session must wait, enter the mpls ldp igp sync holddown command. If the LDP peer is not reachable, the IGP establishes the adjacency to enable the LDP session to be established. When an IGP adjacency is established on a link but LDP-IGP synchronization is not yet achieved or is lost, the IGP advertises the max-metric on that link. QUESTION 20 Layer 3 VPN is the primary service running on your network. You have POP locations and recently you have seen memory and CPU utilization go above 90% in two out put of four PE devices in one POP location. You have maximum-route-limit configured for each VPN. What additional parameter should be monitored proactively to address these issues? A. Number of prefixes per VRF route in the router B. Number of VRFs configured on each Router C. Number of route targets for each VRF Build Your Dreams PassGuide D. LDP neighbor statistics for any flaps E. Packets in and out for each VRF Correct Answer: D

26 QUESTION 21 Which MPLS layer 2 VPN services strip 802.1q tags before encapsulating the frame? (Choose two) A. Ethernet over MPLS port mode B. Ethernet over MPLS VLAN mode C. MPLS Bridging D. MPLS VPLS Correct Answer: BD A Psuedowire is an industry term for transport of any frames over an MPLS network using MPLS to encapsulate and LDP as a signalling mechanism. Cisco calls this AToM for Any Transport over MPLS and this is the building block of Layer 2 VPNs over MPLS. Pseudowires can be used to deliver two types of services to end users: virtual private wire service (VPWS) and virtual private LAN service (VPLS). The second market adopting MPLS in access networks is the wireline service provider segment, which offers transparent Ethernet private-line services over copper and fiber access networks. While networking standards such as IEEE 802.1QinQ and 802.1ad have enabled transparent Ethernet private-line services for some time, they are limited in scale to the traditional limit of 4096 VLANs per trunk, limiting their ability to operate efficiently in access network implementations. These technologies also introduce complex operations into the provider network to translate VLAN tags. MPLS pseudowires eliminate this scale limitation completely and simplify VLAN tag manipulation, as the VLAN tags are simply stripped off on entry to the pseudowire and reapplied at the egress of the pseudowire. QUESTION 22 Refer to the exhibit.

27 Which two statements are true? (Choose two) A is directly connected subnet B. The router is advertising label 20 destinations C. The upstream P router is perform PHP for destinations on D. The forward data to device on the network the router will remove label 22 and Build Your Dreams PassGuide impose label 23 Correct Answer: BC

28 imp -null for QUESTION 23 Refer to the exhibit. The command was executed on cisco XR12000 series router. The router is directly connected to a remote PE, which has router ID of A single CE is connected to the remote PE. Based on the command output, which label location mode is remote PE running? A. Per-prefix

29 B. Per-ce C. Per-vrf D. Per-pe Correct Answer: C The MPLS VPN Per VRF Label feature (hereafter, in this document, referred to as the Per VRF Label feature or the Per VRF feature) allows you to configure a single Virtual Private Network (VPN) label for all local routes in the entire VPN routing and forwarding (VRF) domain on Cisco 6500 routers. This MPLS VPN Per VRF Label feature incorporates a single (per VRF) VPN label that for all local routes in the VRF table. You can enable (or disable) the MPLS VPN Per VRF Label feature in global configuration mode. This feature is available for the Cisco 6500 router only. QUESTION 24 Refer to the exhibit. The command on the diagram was executed from a cisco ASR 9000 router. Which statement is true? Build Your Dreams PassGuide A is router ID of the ASR9000 B. The ASR 9000 will use label to reach C. The ASR 9000 will perform penultimate hop popping on packets destined to D. The ASR 9000 advertises a label of IMP-NULL to its peers for reachability Correct Answer: C

30 QUESTION 25 You have implemented IMPLS-TE on the core and enabled Fast Reroute. BFD is configured on the core facing links. Every thing was working normally until last month when you added video service on the network. Because of business requirements, video packets are treated as high priority and 70% of bandwidth is allocated for the low latency queue. Recently you noticed BFD session losses and MPLS-TE tunnel flaps on the network. Which parameter should you have mentioned proactively to avoid this issue? A. BFD session timers and hello message B. MPLS-TE tunnel bandwidth and utilization C. QoS drops each class of service on core-facing links D. CPU utilization on the PE routers E. Latency and jitter between PE routers Correct Answer: A QUESTION 26 Which decode corresponds correctly to this MPLS header. 0x00 0x04 0xAB 0xFE? A. Label: 0004, Exp AB. S:1.TTL:7E B. Label: 0004A. TTL:BF.Exp:8. S:0 C. Label: 0004A, Exp: 5, S: 1, TTL: FE D. Label: TTL:AB.Exp:7E.S:1 Correct Answer: C 0x00 0x04 0xAB 0xFE I GET Label 0004A (20 bits) Exp 101s (3 bits) S eee1 (1 bit)

31 TTL FE (8 bits) QUESTION 27 What four layer 2 MPLS VPN parameters are collected from a customer service record database to troubleshoot a VPN connectivity issue? (Choose four) A. Attachment circuit information B. UNI interface encapsulation C. Hop-by-hop LDP information D. Virtual circuit ID information E. Unique service identifier F. PE loopback information Build Your Dreams

32 PassGuide G. Layer 2 MPLS VPN service type Correct Answer: ABDG Virtual Circuit Connection Verification (VCCV) is an L2VPN Operations, Administration, and Maintenance (OAM) feature that allows network operators to run IP-based provider edge (PE)-to-PE keepalive protocol across a specified pseudowire to ensure that the pseudowire data path forwarding does not contain any faults. The disposition PE receives VCCV packets on a control channel, which is associated with the specified pseudowire. The control channel type and connectivity verification type, which are used for VCCV, are negotiated when the pseudowire is established between the PEs for each direction. Two types of packets can arrive at the disposition egress: Type 1 Specifies normal Ethernet over MPLS (EoMPLS) data packets. Type 2 Specifies VCCV packets. Before you can implement MPLS L2VPN on a connection, you must create and configure an attachment circuit (AC) to host L2VPN, Supported Ethernet Encapsulation on UNI The Ethernet User-Network Interface (UNI) is the connection between a cable modem and a customer premise equipment such as a router or a switch. The service provider may or may not use any encapsulation on the UNI. The MPLS Pseudowire for Cable L2VPN feature supports the following transport types on an Ethernet UNI: Port-based UNI (independent of any VLAN) The port-based UNI provides Metro Ethernet Forum (MEF)- defined Ethernet Private Line (EPL) service. In this transport type, an MPLS pseudowire is mapped to the Ethernet port. VLAN-based UNI Ethernet VLAN using 802.1q encapsulation (including stacked VLANs). The VLAN-based UNI provides MEF-defined Ethernet Virtual Private Line (EVPL) service. In this transport type, the MPLS pseudowire is mapped to the 802.1q VLAN QUESTION 28 The SP NOC has determined that a significant number of broadcast packets are being received from customer A. which could be a DoS attack. Customer A is using MPLS layer VPLS services the exercise broadcast traffic is causing degrading performance and over utilizing the access links. Which of the cisco IOS XR MPLS layer 2 configuration parameters can be used to mitigate the problem? A. The storm control parameter under the 12vpn bridge group B. The storm control parameter under the 12vpn xconnect group C. The limit-broadcast parameter under the 12vpn bridge group D. The storm control parameter under the 12vpn xconnect Build Your Dreams PassGuide Correct Answer: A

33 QUESTION 29 A customer has stated that they can not access network /24 from one of there sites (Site c). The customer has a layer 3 MPLS VPN between three sites (site A, site B, site C) connected in full mesh topology. They do not have any issues with accessing after network addresses located in site A and site B. Assuring the PE devices are running Cisco IOS, what are the two troubleshooting commands you should execute on the PE router connected to site C A. Show ip vrf VRFNAME detail to check the route targets B. Show ip vrf VRFNAME detail to check the vrf routes C. Show mpls 12transport binding to check local and remote labels D. Show MPLS interfaces INTERFACENAME detail to check MTU size E. Show ip bgp vpnv4 vrf VRFNAME to check advertised VPNv4 prefixes

34 Correct Answer: BE QUESTION 30 Refer to the exhibit.

35 The command was executed on a cisco XR12000 series router. Which statement about the tunnel displayed is true? Build Your Dreams PassGuide A. The command was executed on the head end of the tunnel B. A label of will be used to reach the next hop for the tunnel C is the IP address of remote interface of the next downstream hop for the tunnel. D. The command was executed on the tail end of the tunnel Correct Answer: D

36 QUESTION 31 Refer to the exhibit.

37 The commands were executing from VKG-3, which is the cisco ASR 9000 Series router. Which statement is true? A. Layer 2 reachability can be achieved between 7200a and 7200b with the current configuration on VKG-3 B. Layer 2 reachability between 7200a and 7200b will fail because of VLAN mismatch configured on VKG-3 C. Layer 2 reachability between 7200a and 7200b will fail because VKG-3 needs "rewrite egress tag push 1 symmetric " configured under both interfaces D. Layer 2 reachability between 7200a and 7200b will fail because the MTU needs to be Build Your Dreams PassGuide increased 1504 to include for the VLAN header file Correct Answer: A

38 QUESTION 32 What are three characteristics that define MP-BGP performance? (Choose three) A. Convergence upon failure and recovery B. Time to establish a tunnel C. Import and export of VPNv4 routes D. Time to complete a SPF calculation E. Route table scanning for changes F. Time to synchronize with LDP Correct Answer: ACE???????? QUESTION 33 Refer to the exhibit.

39 Which statement best describes the Cisco IOS XR VRF protection that is configured? A. The maximum number of configured VPNs is limited to 1000 with an active limit of 75 B. The number of prefixes for VPNs number 1000 is limited to 75 C. The number of VRF table entries is limited to 1000, and a syslog message will be sent at 75% D. The maximum number of pseudowire VCs is limited to 1000 and a syslog message will be Build Your Dreams PassGuide sent at 75% Correct Answer: C

40 QUESTION 34 Refer to the exhibit. The show interface statistic was taken five minutes after the interface counter was cleared. What problem is indicated in the exhibit? A. The hardware forwarding capacity of the router has been exceeded B. The IGP and LDP of router need to be synchronized C. The RP has just failed over from the primary to standby D. The IGP timers of the router need to be turned

41 Correct Answer: A QUESTION 35 Refer to the exhibit. Build Your Dreams PassGuide What could cause the pseudowire for bridge group GROUP5 to be down? A. An interface along the LSP is not running LDP B. The PW type needs to be changed to be VLAN mode C. The MTU needs to be increased by four to include the VLAN header D. The local and remote labels do not match Correct Answer: D

42 QUESTION 36 Which two statements describe when deployment of IP SLA could be regarded as standard or minor change as defined by ITIL? (Choose two) A. A low-frequency probe is being placed on one router for limited time. B. A high-frequency probe is being placed on one router for limited time. C. A low-frequency probe is being deployed to a few routers for a limited time. D. A low-frequency probe is being deployed to a few routers permanently E. A low-frequency probe is being deployed across the network for limited time F. A low-frequency probe is being deployed across the network permanently Correct Answer: AC Build Your Dreams PassGuide

43 QUESTION 37 Refer to the exhibit. Some of your customers are reporting poor network performance when they use FTP to transfer large data files across your MPLS VPN core. Recently, some backbone links in your MPLS VPN core have been upgraded from POS OC-48 to the new 10 Gigabit Ethernet. You have collected the output of the traceroute mpls ipv4 command with the remote PE as Destination. All devices are running cisco IOS. What must be fixed in network to resolve the issue? A. MPLS should be enabled on router ID B. MTU on has to be reduced to C. Exp is set to 0, which causes FTP traffic to be dropped. D. MTU on should be changed to Correct Answer: A

44 original answer was MTU but...

45 QUESTION 38 You have designed and implemented MPLS-TE for fast router in your network core. Your network core consists of Cisco CRS-1 carrier routing System devices interconnected using XDM and Sonet Transport. You are using OSPF as the IGP, and MP-BGP is running on the PE devices to support Layer 3 VPN services. You are offering voice service over VPN circuits. So you want a link convergence of no greater than 100ms. Which option should you use for faster link failure detection and to improve the performance of your network? A. Use OSPF fast hello packets with dead-interval and hello multiplier B. Reduce MP-BGP hello timers between the neighbors C. Configure MPLS-TE tunnels with the dynamic backup option D. Configure MPLS-TE tunnels to autoroute announce Build Your Dreams PassGuide E. Configure BFD on the core links with the appropriate BFD multiplier. Correct Answer: E

46 QUESTION 39 Which two IP SLA probe types can be used to monitor MPLS and VPNs for SLA compliance? (Choose two) A. UDP echo B. UDP echo ping C. MPLS LSP ping D. UDP delay E. VRF F. HTTP Correct Answer: CE

47

48 QUESTION 40 Refer to the exhibit.

49 Given the partial configuration, which statement is true? A. The router is a P router B. The router is a CE router C. The router is a PE router D. The router is a customer oriented behind the CE router Build Your Dreams PassGuide Correct Answer: C not a private address QUESTION 41 What happens to a captured ingress MPLS packet that has the header 0x00 0x00 0x7B 0x01? A. The packet will be dropped because it uses an incorrect label B. The packet will be dropped because it reached its TTL limit C. The packet will be dropped because its EXP value is corrupted D. The packet will be MPLS switched because nothing is wrong with it Correct Answer: B 0x00 0x00 0x7B 0x01 Label x bits

50 Exp 101s 3 bits S eee1 1 bit TTL 01 8 bits 3 3 QUESTION 42 Which four tasks are used to configure MPLS? (Choose four) A. Create a VRF instance for the VPN B. Assign customer interfaces (access links ) to a VPN C. Enable the VFI and MPLS encapsulation D. Configure the TE tunnel per PE interface E. Configure the IP address on the VRF interface or subinterface F. Configure the CE to PE customer routing Correct Answer: ABCE

51 mp_vpn_ipv4_ipv6_ps6922_tsd_products_configuration_guide_chapter.html Configure a VRF for IPv4/V6 Associate a Multiprotocol VRF with an Interface Configure an interface type and enters interface configuration mode. Associate a VRF with an interface or subinterface Set a primary or secondary IP address for an interface QUESTION 43 Which three layer 2 products are supported on the attachment circuit by Cisco IOS Layer 2 VPNs? (Choose three) A. EtherChannel B. Token Ring C. HDLC D. Multilink PPP' E. Frame Relay Build Your Dreams PassGuide F. AAL5 Correct Answer: CEF

52 I think original answer of C/D/E is wrong it should be C/E/F

53 Originally had Multi PPP and was C/D/E not my answer QUESTION 44 Customer A is experiencing intermittent network performance problems. The SP NOC has determined that the "MPLS blackhole" is occurring during network convergence events. The suspected cause of the PLS VPN traffic is that the customer's IGP (OSPF) is converging than the LDP. What MPLS feature can be configured to eliminate the problem? A. Decrease the OSPF convergence timing (throttle timer) B. MPLS VRF protection feature C. MPLS fast reroute feature D. MPLS LDP Sync feature in OSPF E. Use Cisco MPLS Auto bandwidth Allocator Correct Answer: D

54 Packet loss can occur because the actions of the IGP and LDP are not synchronized. Packet loss can occur in the following situations: When an IGP adjacency is established, the router begins forwarding packets using the new adjacency before the LDP label exchange completes between the peers on that link. If an LDP session closes, the router continues to forward traffic using the link associated with the LDP peer rather than an alternate pathway with a fully synchronized LDP session. The MPLS LDP-IGP Synchronization feature: Provides a means to synchronize LDP and IGPs to minimize MPLS packet loss. Enables you to globally enable LDP-IGP Synchronization on each interface associated with an IGP Open Shortest Path First (OSPF) or IS-IS process. Provides a means to disable LDP-IGP Synchronization on interfaces that you do not want enabled. Prevents MPLS packet loss due to synchronization conflicts. Works when LDP is enabled on interfaces using either the mpls ip or mpls ldp autoconfig command. To enable LDP-IGP Synchronization on each interface that belongs to an OSPF or IS-IS process, enter the mpls ldp sync command. If you do not want some of the interfaces to have LDP-IGP Synchronization enabled, issue the no mpls ldp igp sync command on those interfaces. If the LDP peer is reachable, the IGP waits indefinitely (by default) for synchronization to be achieved. To limit the length of time the IGP session must wait, enter the mpls ldp igp sync holddown command. If the LDP peer is not reachable, the IGP establishes the adjacency to enable the LDP session to be established. When an IGP adjacency is established on a link but LDP-IGP Synchronization is not yet achieved or is lost, the IGP advertises the max-metric on that link QUESTION 45 Refer to the exhibit. A service provider sees the following output indicating some problems. What are two possible causes?

55 (Choose two) A. The router has not been configured with SSO B. The router has been inappropriately dimensioned policy feature card C. The IGP timers of the router have been overturned D. The router has not been configured with MPLS TE automatic tunnels and fast Reroute E. The router has too many entries on its routing table Build Your Dreams PassGuide Correct Answer: BE QUESTION 46 When MPLS VPN services are implemented, which CE-PE routing method does not require the use of the redistribute command to advertise customer routes between sites? A. Static routing B. RIP C. EIGRP D. OSPF E. BGP Correct Answer: E QUESTION 47 You have configured a layer 2 VPN circuit between two routers, PE1 and PE4. For some reason the VC circuit Is not coming up. You checked the status and VC was downed at both sides. After careful verification you have ruled out any layer 2 VPN control plane configuration issues. Assuring that PE devices are running cisco IOS, what two additional troubleshooting steps should help identifying the problem? (Choose two) A. Show mpls forwarding-table for local circuit mismatch B. Show mpls 12transport hw-capability to check hardware capability C. Show mpls 12transport binding to check for MTU D. Show MPL12transport binding to check VC labels Correct Answer: D

56 QUESTION 48 What does this Cease Notification Syslog message indicate? May CET: % BGP-3-NOTIFICATION: received from neighbor /1 (cease) 0 bytes. A. The port is shut down B. The connection was rejected C. BGP became disabled D. The maximum number of prefixes was reached Correct Answer: B should it be SET CET: % BGP-3-NOTIFICATION e,g. Use the maximum-prefix command to configure a maximum number of prefixes that a BGP router is allowed to receive from a neighbor. It adds another mechanism (besides routing policy) to control prefixes received from a peer. When the number of received prefixes exceeds the maximum number configured, the software terminates the peering, by default, after sending a cease notification to the neighbor. However, if the warning-only keyword is configured, the software writes only a log message, but continues peering with the sender. If the peer is terminated, the peer stays down until the clear bgp command is issued. This command takes effect immediately if configured on an established neighbor unless the number of prefixes received from the neighbor already exceeds the configured limits. If this command is configured for a neighbor group or neighbor address family group, all neighbors using the group inherit the configuration. Values of commands configured specifically for a neighbor override inherited values. QUESTION 49 You want to collect net flow-related information from your core links. You also want label switch traffic to be included in the information collected by NetFlow. You have MPLS, MPLS VPN, and protected TE tunnel in your core. How many labels should NetFlow analyze to collect information for all types of MPLS applications used in

57 your core network? Build Your Dreams PassGuide A. Two labels B. Three labels C. four labels D. five labels Correct Answer: B QUESTION 50 When MPLS layer 3 VPN services are implemented, what is the function of the VRF table? A. The VRF table determines the pseudowire virtual circuits used to for forward labeled packets B. Multiple VRF instances are used to isolate potently overlapping routing and forwarding information for VPNs. C. VRF tables are used to translate IP routing prefixes D. OSPF and IS-IS routing prefixes are MAPPED to there corresponding MPLS labeled prefixes in the VRF table. The prefixes are used by the PE to map forwarded packets between MPLS and NON-MPLS circuits Correct Answer: B QUESTION 51 Which cisco IOS command should be used to verify that frames are being forwarded on a VC by an egress PE? A. Show MPLS forwarding tables B. Show MPLS interface forwarding C. Show 12 VPN counters forwarding session D. Show 12 VPN counters forwarding statistics Correct Answer: A

58 QUESTION 52 Your company has decided to deploy a MPLS network with VPNs. The customer that will be using the network is demanding service level agreements with your company. How can you monitor the SLAs for violations? A. RMON

59 B. Event management system C. Asset management system D. CNR E. IP SLA Build Your Dreams PassGuide Correct Answer: E QUESTION 53 Which command should be used to verify that IS-IS has been properly configured to support MPLS TE? A. Show mpls isis traffic-eng advertisements B. Show isis mpls traffic-eng adjacency-log C. Show isis mpls traffic-eng advertisements D. Show isis mpls traffic-eng tunnel E. Show mpls isis traffic-eng adjacency-log Correct Answer: C

60 QUESTION 54 Which statement about LSP ping is true? A. LSP ping access ICMP packets B. A successful LSP ping ensures that the echo-reply are labled

61 C. If an IP ping exceeds, than an LSP ping succeed if MPLS is enabled along the path D. A successful LSP ping validates reachability to the destination along the MPLS data plane Correct Answer: D QUESTION 55 What does the auto tunnel template interface configure? A. MPLS TE tunnel mesh groups B. Virtual private LAN services C. MPLS VPN VRF instances D. MP-BGP peering

62 E. LDP tunnels F. MPLS TE tunnel dynamic route Correct Answer: A AutoTunnel Template Interfaces An autotunnel template interface is a logical entity; that is, it is a configuration for a tunnel interface that is not tied to specific tunnel interfaces. It can be applied dynamically, when needed. Mesh tunnel interfaces are tunnel interfaces that are created, configured dynamically (for example, by the applying [or cloning] of a template interface), used, and then freed when they are no longer needed. A mesh tunnel interface obtains its configuration information from a template, except for the tunnel's destination address, which it obtains from the TE topology database that matches an access list or from the IGP mesh group advertisement. The template interface allows you to enter commands once per mesh group. These commands specify how mesh tunnel interfaces are created. Each time a new router is added to the network, a new mesh tunnel interface is created. The configuration of the interface is duplicated from the template. Each mesh tunnel interface has the same path constraints and other parameters configured on the template interface. Only the tunnel destination address is different. QUESTION 56 You have been asked to compare parameters of layer 2 MPLS vpn services at two remote ends using the show mpls l2 binding command What three items of relevant information should you use to ensure that layer two VPN parameters are configured correctly? (Choose three) A. Local and remote labels B. Encapsulation Build Your Dreams PassGuide C. VC type D. VCCV E. VC ID F. MTU Correct Answer: ACD

63 QUESTION 57 Refer to the exhibit. While configuring the customer access link is cisco IOS XR software. What must be done when assigning an interface to the VRF? A. Configure the neighbor LDP before accessing the interface to the VRF B. Configure the IP address to the interface before assigning the interface to the VRF C. Remove the customer access link before assigning the interface to the VRF D. Remove any address configured before assigning the interface to the VRF Correct Answer: D

64 QUESTION 58 Refer to the exhibit. Build Your Dreams PassGuide With this template configured and applied to cisco XR 12000series Router, could a CPE device use the traceroute command to reveal the core network? A. Yes, traceroute is not disabled. B. Yes, discovery targeted-hello accept allows it C. No it is disabled with mpls ip-ttl-propagate disable D. No, session protection stops traceroute E. Only if traceroute mpls was used F. Only if traceroute 6 was used Correct Answer: C QUESTION 59 What function does the penultimate LSR perform to help optimize MPLS?

65 A. Pops the label before packet reaches the PE router B. Restore the original ingress settings to the EXP field C. Ensure that the LSP is Taking the shortest path D. Verifies that there are no loops in the path Correct Answer: A QUESTION 60 Refer to the exhibit. Build Your Dreams PassGuide The partial show run command out put is from PE router that provides MPLS VPN services to customer_1. What is the routing protocol and AS number used between the PE router and customer_1 CE router? A. BGP AS B. Multiprotocol BGP C. EIGRP AS 10 D. EIGRP AS 20

66 Correct Answer: D Actualtest says AS 20 not AS 10

67 QUESTION 61 Refer to the exhibit.

68 You are troubleshooting a connectivity problem between the CE routers in your network running IS-IS. You login to one of the routers and execute a show log. What is the problem associated with these message? Build Your Dreams PassGuide A. Protocol mismatch B. Mismatch area ID C. Mismatch MTU size D. Mismatch of features E. Wrong ip address applied Correct Answer: D QUESTION 62 What minimum commands are necessary to initiate MPLS on a cisco IOS router? A. In global configuration mode, execute the mpls ip command B. In global configuration mode, execute the mpls ip command on every participating interface. C. In global configuration mode, execute the mpls ip command. Interface configuration mode executes the mpls ip command on every participating interface. D. In global configuration mode, execute the mpls ip command in Mpls configuration mode specifies each participating interface using the interface interface command. Correct Answer: B Build Your Dreams QUESTION 63 Directed LDP sessions are used by MPLS to exchange labels with nonadjacent routers. How are directed LDP sessions different from normal LDP sessions? A. The hello packets are addressed with a statically configured destination address. B. The ":0" LDP identifier is added to the destination IP address to indicate the label space. C. Directed LDP hello messages are sent to the multicast address D. TCP and UDP well-known port 646 is used for directed LDP sessions only. Correct Answer: A The only difference between directly and non-directly connected neighbors is in how they discover each other. LSRs discover directly connected neighbors by sending LDP hello messages encapsulated in UDP to the multicast address (all routers on a subnet). These packets are known as hello messages. Non-directly connected neighbors can't be reached through a multicast UDP packet. So, the same hello

69 messages are sent as unicasts (also to UDP port 646). This requires that an LSR know ahead of time who it wants to have as a non-directly connected neighbor. This can be achieved through configuration. Directly connected neighbors These neighbors have a Layer 2 connection between them. So, routers that are connected by any Layer 2 linkwhether a POS link, an ATM PVC, an Ethernet connection, or a DS-3 interfaceare considered directly connected for LDP. Neighbors connected by a logical connection such as GRE tunnel are also considered directly connected. The basic commonality over such connections is the fact that a neighbor is one IP hop away. Non-directly connected neighbors These neighbors do not have a Layer 2 connection between them. More importantly, these neighbors are several IP hops away. Routers that are connected to each other by MPLS traffic engineering tunnels and that have LDP enabled on them are considered non-directly connected. Such an LDP session is called a targeted or directed LDP session QUESTION 64 Which MPLS Layer 2 VPN service allows transparent bridging of VLAN trunks over MPLS? A. Ethernet over MPLS Port Mode B. Ethernet over MPLS VLAN Mode C. MPLS Bridging D. MPLS VPLS Correct Answer: A QUESTION 65 Refer to the exhibit. Build Your Dreams PassGuide

70 The commands were exceeded on the cisco XR PE. Which statement is true? A. The outer label for prefix is B. The outer label for prefix is C. The outer label for prefix is implnull. D. Prefix has no outer label. Correct Answer: A

71 QUESTION 66 If you are configuring MP-BGP routing for MPLS Layer 3 VPNs, when should the redistribute connected command be used? A. when the customer requires a static default route to be advertised B. when the PE is supporting more than one VRF instance for the same customer CE C. when the customer does not have CE routers and the PE is the default gateway D. every time the MP-BGP redistribution function is enabled Correct Answer: C QUESTION 67 You have designed and implemented MPLS-TE for fast router in your network core. Your network core consists of Cisco CRS-1 carrier routing System devices interconnected using XDM and Sonet Transport. You are using OSPF as the IGP, and MP-BGP is running on the PE devices to support Layer 3 VPN services. You are offering voice service over VPN circuits. So you want a link convergence of no greater than 100ms. Which option should you use for faster link failure detection and to improve the performance of your network?

72 A. Use OSPF fast hello packets with dead-interval and hello multiplier B. Reduce MP-BGP hello timers between the neighbors C. Configure MPLS-TE tunnels with the dynamic backup option D. Configure MPLS-TE tunnels to autoroute announce Build Your Dreams PassGuide E. Configure BFD on the core links with the appropriate BFD multiplier. Correct Answer: E QUESTION 68 Refer to the exhibit. Build Your Dreams PassGuide With this template configured and applied to cisco XR 12000series Router, could a CPE device use the traceroute command to reveal the core network? A. Yes, traceroute is not disabled. B. Yes, discovery targeted-hello accept allows it C. No it is disabled with mpls ip-ttl-propagate disable D. No, session protection stops traceroute

73 E. Only if traceroute mpls was used F. Only if traceroute 6 was used Correct Answer: C QUESTION 69 What Cisco IOS MPLS Layer 2 service is configured? A. Ethernet over MPLS Port Mode B. Ethernet over MPLS VLAN Mode C. MPLS Bridging D. MPLS VPLS Correct Answer: B

74 QUESTION 70

75 What MPLS Layer 2 service is being enabled? A. Ethernet over MPLS Port Mode B. Ethernet over MPLS VLAN Mode C. MPLS Bridging D. MPLS VPLS Correct Answer: A

76 QUESTION 71 When configuring MPLS Layer 2 VPLS, why is the Virtual Forwarding Instance needed? A. The VFI is used to create a full mesh of pseudowire (VC) circuits. B. The VFI learns the destination MAC addresses. C. The VFI lists the PE endpoints for Auto Discovery D. The VFI defines the cross-connect group Correct Answer: B

77 QUESTION 72 You have been asked to verify if the OSPF protocol is enabled for Layer 3 MPLS VPN service on the link between the PE and CE. Assume the PE is running on Cisco IOS XR software. Which command should be used to verify that the OSPF protocol is enabled for Layer 3 MPLS VPN service on a link between a PE router and a CE router? A. show ip ospf interface brief B. show vrf VRFNAME detail C. show ospf vrf VRFNAME interface brief D. show ospf interface brief

78 E. show ip protocols Correct Answer: C QUESTION 73 Which command is most likely to be useful when you troubleshoot a unidirectional connectivity problem on a VC? A. show mpls l2transport vc B. show mpls l2transport vc detail C. show mpls l2transport checkpoint D. show mpls l2transport summary Correct Answer: B

79 QUESTION 74 What Cisco IOS command should be used to obtain tunnel statistics for dynamically created primary tunnels? A. show mpls traffic-eng tunnels auto-bw brief

80 B. show mpls traffic-eng tunnels C. show mpls traffic-eng tunnels statistics D. show mpls traffic-eng topology Correct Answer: B QUESTION 75

81 The output from the debug command is from the Cisco XR12000 Series Router. Which statement is true? A. The output is the result of a single iteration of mpls ping executed on the Cisco ASR 9000 Series Router B. The output is the result of a single iteration of mpls traceroute executed on the ASR C. The packet did not reach its destination because the control word was not found D. The output is the result of a single iteration of mpls ping executed on the Cisco CRS-1 Carrier Routing System. Correct Answer: B

82

83 Exam B QUESTION 1 Drag the attributes on the left to the appropriate categories on the right. Note that not all slots may be uses. Select and Place: Correct Answer:

84 QUESTION 2 Refer to Exhibit. MPLS-TE is configured in the core and BFD is used for faster link failure detection. Currently the MPLS-TE tunnels are flapping. Identify the Symptom of the flapping, the root cause of the issue, and the resolution. Click and drag the elements on the left to the correct identifier on the right. It is possible that you will not use all the elements. Select and Place:

85 Correct Answer:

86 The BFD Session is flapping at core routers = Symptom The BFD interval is misconfigured on core routers = Root Cause Change the BFD interval on core routers = Resolution QUESTION 3 Drag the list of commands on the left to the proper command categories on the right. Select and Place:

87 Correct Answer:

88 QUESTION 4 Which protocol must be enabled to successfully deploy MPLS TE? A. OSPF B. IS-IS C. EIGRP D. BGPv4 E. MP-BGP F. RSVP Correct Answer: F QUESTION 5 Your company has decided to deploy a MPLS network with VPNs. The customer that will be using the network is demanding service level agreements with your company. What OSS system should violations be

89 sent to? A. RMON B. event management system C. asset management system D. CNR E. IP SLA Correct Answer: B QUESTION 6 Refer to the exhibit. ***Exhibit is missing*** An operator is about to enter this configuration into a PE router. What is the problem with this configuration? A. It uses the wrong command for starting immediately. B. The prefix must be specified in dotted decimal notation. C. It does not specify the test protocol first. D. The schedule line should begin "schedule ip sla". Correct Answer: C??????????? QUESTION 7 Refer to the exhibit. MPLS header: 0x00 0x05 0x4B 0x7E class-map match-any high-priority match mpls experimental 5 class-map match-any app-data match mpls experimental class-map match-any internet

90 Based on the MPLS header, what class of traffic is matched against the match mpls experimental 0 packet? A. class high-priority B. class app-data C. class internet D. class default Correct Answer: A 0x00 0x05 0x4B 0x7E Label 0005a Exp 101x S bit xxx1 TTL 7E QUESTION 8 Refer to the exhibit. **** Exhinit missing ***** The command was executed on a Cisco ASR 9000 Series Router. Which statement is true? A. The tunnel, tunnel-te1, has been configured to be used by the IGP. B. A maximum of 1 kb/s of traffic can pass through tunnel-te1. C. Traffic on tunnel-te1 will pass through two other routers before reaching the tail-end router. D. When an echo request is sent through the tunnel-te1, the echo-reply will come back through tunnel-te1.

91 Correct Answer: A QUESTION 9 What does the MP-BGP AFI identifier indicate? A. which protocol an update is for B. whether updates are for MPLS VPN or MPLS TE C. whether or not route targets are present in the update D. which extended community attribute is being carried E. which VRF information is being carried in the update Correct Answer: A QUESTION 10 What function does PCALC perform for MPLS TE? A. Properly load balances data over MPLS TE tunnels. B. Calculates the shortest path based on more than cost. C. Tracks the performance of core routers for MPLS TE tunnels. D. It is the calculation used to determine if a router has the resources to accept an RSVP request. Correct Answer: B

92 QUESTION 11 Which protocol must be enabled to successfully deploy Layer 3 MPLS VPNs? A. OSPF B. IS-IS C. EIGRP D. MP-BGP E. RSVP Correct Answer: D QUESTION 12 How does a Label Switch Router recognize the label at the bottom of a label stack? A. The bottom-of-stack bit is set. B. The TTL field contains the number 1. C. The EXP field contains the number 1. D. The last bit in the label field is cleared in the bottom label. Correct Answer: A QUESTION 13 You are using VPLS service to transport video across different points in your network. VPLS circuits are discovered automatically using the MP-BGP. A new PE device was added to the network, but VPLS circuits were not discovered by the new PE device. Assuming that PE devices are running Cisco IOS, what two important things must you look for to