Q1. Refer to the exhibit.
What password will be required to enter privileged EXEC mode on a device with the given configuration?
A. ciscotest
B. ciscocert
C. cisco
D. ciscors
E. ciscoccie
Answer: A
Q2. Refer to the exhibit.
Which statement about configuring the switch to manage traffic is true?
A. The switchport priority extend cos command on interface FastEthernet0/0 prevents traffic to and from the PC from taking advantage of the high-priority data queue that is assigned to the IP phone.
B. The switchport priority extend cos command on interface FastEthernet0/0 enables traffic to and from the PC to use the high priority data queue that is assigned to the IP phone.
C. When the switch is configured to trust the CoS label of incoming traffic, the trusted boundary feature is disabled automatically.
D. The mls qos cos override command on interface FastEthernet0/0 configures the port to trust the CoS label of traffic to and from the PC.
Answer: A
Explanation:
In some situations, you can prevent a PC connected to the Cisco IP Phone from taking advantage of a high-priority data queue. You can use the switchport priority extend cos interface configuration command to configure the telephone through the switch CLI to override the priority of the traffic received from the PC.
Reference: http://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2950/software/release/12-1_22_ea2/configuration/guide/2950scg/swqos.html
Q3. Which two improvements do SIA-Query and SIA-Reply messages add to EIGRP? (Choose two.)
A. Stuck-in-active conditions are solved faster.
B. They prevent a route from going into the stuck-in-active state.
C. They help in the localization of the real failure in the network.
D. The EIGRP adjacency between two neighbors never goes down.
Answer: A,C
Q4. Refer to the exhibit.
Which statement is true?
A. 2001:DB8::1/128 is a local host route, and it can be redistributed into a dynamic routing protocol.
B. 2001:DB8::1/128 is a local host route, and it cannot be redistributed into a dynamic routing protocol.
C. 2001:DB8::1/128 is a local host route that was created because ipv6 unicast-routing is not enabled on this router.
D. 2001:DB8::1/128 is a route that was put in the IPv6 routing table because one of this router's loopback interfaces has the IPv6 address 2001:DB8::1/128.
Answer: B
Explanation:
The local routes have the administrative distance of 0. This is the same adminstrative distance as connected routes. However, when you configure redistributed connected under any routing process, the connected routes are redistributed, but the local routes are not. This behavior allows the networks to not require a large number of host routes, because the networks of the interfaces are advertised with their proper masks. These host routes are only needed on the router that owns the IP address in order to process packets destined to that IP address.
It is normal for local host routes to be listed in the IPv4 and IPv6 routing table for IP addresses of the router's interfaces. Their purpose is to create a corresponding CEF entry as a receive entry so that the packets destined to this IP address can be processed by the router itself. These routes cannot be redistributed into any routing protocol.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/ip-routing/116264-technote-ios-00.html
Q5. What is a cause for unicast flooding?
A. Unicast flooding occurs when multicast traffic arrives on a Layer 2 switch that has directly connected multicast receivers.
B. When PIM snooping is not enabled, unicast flooding occurs on the switch that interconnects the PIM-enabled routers.
C. A man-in-the-middle attack can cause the ARP cache of an end host to have the wrong MAC address. Instead of having the MAC address of the default gateway, it has a MAC address of the man-in-the-middle. This causes all traffic to be unicast flooded through the man-in-the-middle, which can then sniff all packets.
D. Forwarding table overflow prevents new MAC addresses from being learned, and packets destined to those MAC addresses are flooded until space becomes available in the forwarding table.
Answer: D
Explanation:
Causes of Flooding The very cause of flooding is that destination MAC address of the packet is not in the L2 forwarding table of the switch. In this case the packet will be flooded out of all forwarding ports in its VLAN (except the port it was received on). Below case studies display most common reasons for destination MAC address not being known to the switch.
Cause 1: Asymmetric Routing
Large amounts of flooded traffic might saturate low-bandwidth links causing network performance issues or complete connectivity outage to devices connected across such low-bandwidth links
Cause 2: Spanning-Tree Protocol Topology Changes
Another common issue caused by flooding is Spanning-Tree Protocol (STP) Topology Change Notification (TCN). TCN is designed to correct forwarding tables after the forwarding topology has changed. This is necessary to avoid a connectivity outage, as after a topology change some destinations previously accessible via particular ports might become accessible via different ports. TCN operates by shortening the forwarding table aging time, such that if the address is not relearned, it will age out and flooding will occur
Cause 3: Forwarding Table Overflow
Another possible cause of flooding can be overflow of the switch forwarding table. In this case, new addresses cannot be learned and packets destined to such addresses are flooded until some space becomes available in the forwarding table. New addresses will then be learned. This is possible but rare, since most modern switches have large enough forwarding tables to accommodate MAC addresses for most designs.
Reference:
http://www.cisco.com/c/en/us/support/docs/switches/catalyst-6000-series-switches/23563-143.html
Q6. DRAG DROP
Drag and drop the PPPoE packet type on the left to the corresponding description on the right.
Answer:
Q7. Which TCP mechanism prevents the sender from sending data too quickly for the receiver to process?
A. Congestion control
B. Error detection
C. Selective acknowledgement
D. Flow control
Answer: D
Explanation:
In data communications, flow control is the process of managing the rate of data transmission between two nodes to prevent a fast sender from overwhelming a slow receiver. It provides a mechanism for the receiver to control the transmission speed, so that the receiving node is not overwhelmed with data from transmitting node.
Reference: http://en.wikipedia.org/wiki/Flow_control_(data)
Q8. Refer to the exhibit.
Which statement about this GETVPN configuration is true?
A. Co-operative key servers are configured.
B. Redundant peers are configured.
C. The key server uses multicast mode to propagate rekey messages.
D. PSK authentication is configured.
Answer: A
Q9. Which measure does IS-IS use to avoid sending traffic with a wrong MTU configuration?
A. IS-IS does not protect from MTU mismatch.
B. MTU value is communicated in IS-IS Sequence Number PDUs (SNP), and IS-IS adjacency is not established if an MTU mismatch is detected.
C. IS-IS uses path MTU discovery as specified in RFC 1063.
D. IS-IS uses padding of hello packets to full MTU.
Answer: D
Explanation:
Intermediate System-to-Intermediate System (IS-IS) hellos are padded to the full maximum transmission unit (MTU) size. The benefit of padding IS-IS Hellos (IIHs) to the full MTU is that it allows for early detection of errors due to transmission problems with large frames or due to mismatched MTUs on adjacent interfaces.
Reference: http://www.cisco.com/c/en/us/support/docs/ip/integrated-intermediate-system-to-intermediate-system-is-is/47201-isis-mtu.html
Q10. 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