Q1. Which statement about OTV is true?
A. The overlay interface becomes active only when configuration is complete and it is manually enabled.
B. OTV data groups can operate only in PIM sparse-mode.
C. The overlay interface becomes active immediately when it is configured.
D. The interface facing the OTV groups must be configured with the highest MTU possible.
Answer: A
Explanation:
OTV has the following configuration guidelines and limitations:
. If the same device serves as the default gateway in a VLAN interface and the OTV edge device for the VLANs being extended, configure OTV on a device (VDC or switch) that is separate from the VLAN interfaces (SVIs).
. When possible, we recommend that you use a separate nondefault VDC for OTV to allow for better manageability and maintenance.
. An overlay interface will only be in an up state if the overlay interface configuration is complete and enabled (no shutdown). The join interface has to be in an up state.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/datacenter/sw/nx-os/OTV/config_guide/b_Cisco_Nexus_7000_Series_NX-OS_OTV_Configuration_Guide/basic-otv.html
Q2. Refer to the exhibit.
AS #1 and AS #2 have multiple EBGP connections with each other. AS #1 wants all return traffic that is destined to the prefix 10.10.10.1/32 to enter through the router R1 from AS #2.
In order to achieve this routing policy, the AS 1 advertises a lower MED from R1, compared to a higher MED from R3, to their respective BGP neighbor for the prefix 10.10.10.0/24. Will this measure guarantee that the routing policy is always in effect?
A. Yes, because MED plays a deterministic role in return traffic engineering in BGP.
B. Yes, because a lower MED forces BGP best-path route selection in AS #2 to choose R1 as the best path for 10.10.10.0/24.
C. Yes, because a lower MED in AS #2 is the highest BGP attribute in BGP best-path route selection.
D. No, AS #2 can choose to alter the weight attribute in R2 for BGP neighbor R1, and this weight value is cascaded across AS #2 for BGP best-path route selection.
E. No, AS #2 can choose to alter the local preference attribute to overwrite the best-path route selection over the lower MED advertisement from AS #1. This local preference attribute is cascaded across AS #2 for the BGP best-path route selection.
Answer: E
Explanation:
MED and AS path prepending can both be used to influence the way incoming traffic from other Autonomous Systems get sent to the local AS, but they provide no guarantee as the other AS ultimately has the final word in how they send traffic. Since local preference is preferred over MED in the BGP decision process, the other AS can configure local preference to override the MED settings you have configured.
Q3. Which two best practices does Cisco recommend to migrate a network from PVST+ to MST? (Choose two.)
A. Start the migration at the edge nodes and work toward the root bridge.
B. Before starting the transition, configure one of the edge nodes with a lower priority so that it becomes the root bridge after the transition.
C. Before starting the transition, ensure that at least two nodes act as the root bridge for all VLANs in the network.
D. Start the migration at the root bridge and work toward the edge nodes.
E. Before starting the transition, configure one of the edge nodes with a higher priority so that it becomes the root bridge after the transition.
F. Before starting the transition, ensure that one node is the root bridge for all VLANs in the network.
Answer: A,F
Q4. DRAG DROP
Drag and drop the StackWise stack master election rule on the left into the correct priority order on the right.
Answer:
Q5. Refer to the exhibit.
Which statement about the R1 configuration is true?
A. It permits host 10.1.1.2 to establish a Telnet connection to R1.
B. It limits remote hosts to two SSH connection attempts.
C. SSH connections to R1 will log out after a 5-minute idle interval.
D. Hosts that reside on network 10.0.0.0/8 can SSH to R1.
E. The R1 timeout for outgoing SSH connection attempts is 30 seconds.
Answer: E
Explanation:
The timeout for outgoing SSH connection is defined by the “ip sshh time-out” command (in seconds), which is configured here as 30.
Q6. What is the destination address of an IGMPv2 general membership query?
A. 224.0.0.1
B. 224.0.1.1
C. 224.0.0.2
D. the multicast group address
Answer: A
Q7. Which two parameters does the Tunnel Mode Auto Selection feature select automatically? (Choose two.)
A. the tunneling protocol
B. the transport protocol
C. the ISAKMP profile
D. the transform-set
E. the tunnel peer
Answer: A,B
Explanation:
The Tunnel Mode Auto Selection feature eases the configuration and spares you about knowing the responder’s details. This feature automatically applies the tunneling protocol (GRE or IPsec) and transport protocol (IPv4 or IPv6) on the virtual template as soon as the IKE profile creates the virtual access interface. This feature is useful on dual stack hubs aggregating multivendor remote access, such as Cisco AnyConnect VPN Client, Microsoft Windows7 Client, and so on.
Reference: http://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sec_conn_vpnips/configuration/xe-3s/sec-sec-for-vpns-w-ipsec-xe-3s-book/sec-ipsec-virt-tunnl.html
Q8. Which two statements are true about VPLS? (Choose two.)
A. It can work over any transport that can forward IP packets.
B. It provides integrated mechanisms to maintain First Hop Resiliency Protocols such as HSRP, VRRP, or GLBP.
C. It includes automatic detection of multihoming.
D. It relies on flooding to propagate MAC address reachability information.
E. It can carry a single VLAN per VPLS instance.
Answer: D,E
Explanation:
VPLS relies on flooding to propagate MAC address reachability information. Therefore, flooding cannot be prevented.
VPLS can carry a single VLAN per VPLS instance. To multiplex multiple VLANs on a single instance, VPLS uses IEEE QinQ.
Reference: http://www.cisco.com/c/en/us/products/collateral/switches/nexus-7000-series-switches/white_paper_c11-574984.html
Q9. DRAG DROP
Drag and drop the multicast protocol or feature on the left to the correct address space on the right.
Answer:
Q10. When the BGP additional-paths feature is used, what allows a BGP speaker to differentiate between the different available paths?
A. The remote BGP peer prepends its own next-hop address to the prefix.
B. A unique path identifier is encoded into a dedicated field to the NLRI.
C. A route distinguisher is appended to the prefix by the receiving BGP speaker.
D. The additional path information is encoded in an extended community.
Answer: B
Q11. Which LSA type is associated with the default route in a totally stubby area?
A. interarea-prefix LSA for ABRs (Type 3)
B. autonomous system external LSA (Type 5)
C. router LSA (Type 1)
D. interarea-router LSAs for ASBRs (Type 4)
Answer: A
Q12. What are two advantages to using Asynchronous mode instead of Demand mode for BFD? (Choose two.)
A. Asynchronous mode requires half as many packets as Demand mode for failure detection.
B. Asynchronous mode can be used in place of the echo function.
C. Asynchronous mode supports a larger number of BFD sessions.
D. Asynchronous mode requires one fourth as many packets as Demand mode for failure detection.
E. Asynchronous mode’s round-trip jitter is less than that of Demand mode.
Answer: A,B
Explanation:
Pure Asynchronous mode is advantageous in that it requires half as many packets to achieve a particular Detection Time as does the Echo function. It is also used when the Echo function cannot be supported for some reason.
Reference: https://tools.ietf.org/html/rfc5880
Q13. Refer to the exhibit.
What will be the IP MTU of tunnel 0?
A. 1500
B. 1524
C. 1476
D. 1452
E. 1548
Answer: C
Explanation:
In the case of the GRE tunnel interface, the IP maximum transmission unit (MTU) is 24 bytes less than the IP MTU of the real outgoing interface. For an Ethernet outgoing interface that means the IP MTU on the tunnel interface would be 1500 minus 24, or 1476 bytes.
Reference: A spoke site that is connected to Router-A cannot reach a spoke site that is connected to Router-B, but both spoke sites can reach the hub. What is the likely cause of this issue http://www.cisco.com/c/en/us/support/docs/ip/generic-routing-encapsulation-gre/13725-56.html
Q14. On an MPLS L3VPN, which two tasks are performed by the PE router? (Choose two.)
A. It exchanges VPNv4 routes with other PE routers.
B. It typically exchanges iBGP routing updates with the CE device.
C. It distributes labels and forwards labeled packets.
D. It exchanges VPNv4 routes with CE devices.
E. It forwards labeled packets between CE devices.
Answer: A,C
Explanation:
MPLS VPN functionality is enabled at the edge of an MPLS network. The PE router performs these tasks: .
Exchanges routing updates with the CE router .
Translates the CE routing information into VPN version 4 (VPNv4) routes .
Exchanges VPNv4 routes with other PE routers through the Multiprotocol Border Gateway Protocol (MP-BGP)
A PE router binds a label to each customer prefix learned from a CE router and includes the label in the network reachability information for the prefix that it advertises to other PE routers. When a PE router forwards a packet received from a CE router across the provider network, it labels the packet with the label learned from the destination PE router. When the destination PE router receives the labeled packet, it pops the label and uses it to direct the packet to the correct CE router. Label forwarding across the provider backbone is based on either dynamic label switching or traffic engineered paths. A customer data packet carries two levels of labels when traversing the backbone
Reference: http://www.cisco.com/c/en/us/td/docs/routers/asr9000/software/asr9k_r4-2/lxvpn/configuration/guide/vcasr9kv342/vcasr9k42v3.html
Q15. Which statement about the BGP scope of the cost community is true?
A. It is shared with IBGP neighbors only.
B. It is shared with IBGP neighbors and route reflectors.
C. It is shared with EBGP neighbors only.
D. It is shared with IBGP and EBGP neighbors.
E. It is shared with IBGP and confederation peers.
Answer: E
Explanation:
The BGP Cost Community feature introduces the cost extended community attribute. The cost community is a non-transitive extended community attribute that is passed to internal BGP (iBGP) and confederation peers but not to external BGP (eBGP) peers. The cost community feature allows you to customize the local route preference and influence the best path selection process by assigning cost values to specific routes.
Reference: http://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/s_bgpcc.html