Q121. - (Topic 7)
What are three factors a network administrator must consider before implementing Netflow
in the network? (Choose three.)
A. CPU utilization
B. where Netflow data will be sent
C. number of devices exporting Netflow data
D. port availability
E. SNMP version
F. WAN encapsulation
Answer: A,B,C
Explanation:
NetFlow has a reputation for increasing CPU utilization on your network devices. Cisco's performance testing seems to indicate that newer hardware can accommodate this load pretty well, but you will still want to check it out before you turn on the feature. Some symptoms of high CPU utilization are very large jitter and increased delay. Services running on the device may also be affected.
Another thing to keep in mind is the amount of data you're going to be sending across the network. Depending on how much traffic you have and how you configure it, the traffic can be substantial. For example, you may not want to send NetFlow data from a datacenter switch to a NetFlow collector on the other side of a small WAN circuit. Also bear in mind that the flows from aggregating large numbers of devices can add up.
Reference: http://searchenterprisewan.techtarget.com/tip/How-the-NetFlow-protocol- monitors-your-WAN
Q122. - (Topic 7)
Scenario
Refer to the topology. Your company has connected the routers R1, R2, and R3 with serial links. R2 and R3 are connected to the switches SW1 and SW2, respectively. SW1 and SW2 are also connected to the routers R4 and R5.
The EIGRP routing protocol is configured.
You are required to troubleshoot and resolve the EIGRP issues between the various routers.
Use the appropriate show commands to troubleshoot the issues.
Which path does traffic take from R1 to R5?
A. The traffic goes through R2.
B. The traffic goes through R3.
C. The traffic is equally load-balanced over R2 and R3.
D. The traffic is unequally load-balanced over R2 and R3.
Answer: A
Explanation:
Using the “show ip int brief command” on R5 we can see the IP addresses assigned to this router. Then, using the “show ip route” command on R1 we can see that to reach 10.5.5.5 and 10.5.5.55 the preferred path is via Serial 1/3, which we see from the diagram is the link to R2.
Q123. - (Topic 8)
Scenario:
You are a junior network engineer for a financial company, and the main office network is experiencing network issues. Troubleshoot the network issues.
Router R1 connects the main office to the internet, and routers R2 and R3 are internal routers.
NAT is enabled on router R1.
The routing protocol that is enabled between routers R1, R2 and R3 is RIPv2.
R1 sends the default route into RIPv2 for the internal routers to forward internet traffic to R1.
You have console access on R1, R2 and R3 devices. Use only show commands to troubleshoot the issues.
Examine the DHCP configuration between R2 and R3; R2 is configured as the DHCP server and R3 as the client. What is the reason R3 is not receiving the IP address via DHCP?
A. On R2. The network statement In the DHCP pool configuration is incorrectly configured.
B. On R3. DHCP is not enabled on the interface that is connected to R2.
C. On R2, the interface that is connected to R3 is in shutdown condition.
D. On R3, the interface that is connected to R2 is in shutdown condition.
Answer: B
Explanation:
Please check the below:
Q124. - (Topic 5)
What is a valid HSRP virtual MAC address?
A. 0000.5E00.01A3
B. 0007.B400.AE01
C. 0000.0C07.AC15
D. 0007.5E00.B301
Answer: C
Explanation:
With HSRP, two or more devices support a virtual router with a fictitious MAC address and unique IP address. There are two version of HSRP.
+ With HSRP version 1, the virtual router’s MAC address is 0000.0c07.ACxx , in which xx is the HSRP group.
+ With HSRP version 2, the virtual MAC address if 0000.0C9F.Fxxx, in which xxx is the HSRP group.
Note: Another case is HSRP for IPv6, in which the MAC address range from 0005.73A0.0000 through 0005.73A0.0FFF.
Q125. - (Topic 5)
What command instructs the device to timestamp Syslog debug messages in milliseconds?
A. service timestamps log datetime localtime<input type
B. service timestamps debug datetime msec<input type
C. service timestamps debug datetime localtime<input type
D. service timestamps log datetime msec
Answer: B
Explanation:
Enable millisecond (msec) timestamps using the service timestamps command: router(config)#service timestamps debug datetime msec.
router(config)#service timestamps log datetime msec The “service timestamps debug”. command configures the system to apply a time stamp to debugging messages. The time- stamp format for datetime is MMM DD HH:MM:SS, where MMM is the month, DD is the date, HH is the hour (in 24-hour notation), MM is the minute, and SS is the second. With the additional keyword msec, the system includes milliseconds in the time stamp, in the format HH:DD:MM:SS.mmm, where .mmm is milliseconds.
Q126. CORRECT TEXT - (Topic 8)
Which protocol authenticates connected devices before allowing them to access the LAN?
A. 802.1d
B. 802.11
C. 802.1w
D. 802.1x
Answer: D
Explanation:
802.1X authentication involves three parties: a supplicant, an authenticator, and an authentication server. The supplicant is a client device (such as a laptop) that wishes to attach to the LAN/WLAN. The term 'supplicant' is also used interchangeably to refer to the software running on the client that provides credentials to the authenticator. The
authenticator is a network device, such as an Ethernet switch or wireless access point; and the authentication server is typically a host running software supporting the RADIUS and EAP protocols.
The authenticator acts like a security guard to a protected network. The supplicant (i.e., client device) is not allowed access through the authenticator to the protected side of the network until the supplicant’s identity has been validated and authorized. An analogy to this is providing a valid visa at the airport's arrival immigration before being allowed to enter the country. With 802.1X port-based authentication, the supplicant provides credentials, such as user name/password or digital certificate, to the authenticator, and the authenticator forwards the credentials to the authentication server for verification. If the authentication server determines the credentials are valid, the supplicant (client device) is allowed to access resources located on the protected side of the network.
Q127. - (Topic 8)
What is one requirement for interfaces to run IPv6?
A. An IPv6 address must be configured on the interface.
B. An IPv4 address must be configured.
C. Stateless autoconfiguration must be enabled after enabling IPv6 on the interface.
D. IPv6 must be enabled with the ipv6 enable command in global configuration mode.
Answer: A
Explanation: To use IPv6 on your router, you must, at a minimum, enable the protocol and assign IPv6 addresses to your interfaces.
Q128. - (Topic 8)
Which statement about switch access ports is true?
A. They drop packets with 802.1Q tags.
B. A VLAN must be assigned to an access port before it is created.
C. They can receive traffic from more than one VLAN with no voice support
D. By default, they carry traffic for VLAN 10.
Answer: A
Explanation:
"If an access port receives a packet with an 802.1Q tag in the header other than the access VLAN value, that port drops the packet without learning its MAC source address."
Q129. - (Topic 3)
Why do large OSPF networks use a hierarchical design? (Choose three.)
A. to decrease latency by increasing bandwidth
B. to reduce routing overhead
C. to speed up convergence
D. to confine network instability to single areas of the network
E. to reduce the complexity of router configuration
F. to lower costs by replacing routers with distribution layer switches
Answer: B,C,D
Explanation:
OSPF implements a two-tier hierarchical routing model that uses a core or backbone tier known as area zero (0). Attached to that backbone via area border routers (ABRs) are a number of secondary tier areas. The hierarchical approach is used to achieve the following:
•Rapid convergence because of link and/or switch failures
•Deterministic traffic recovery
•Scalable and manageable routing hierarchy, reduced routing overhead.
Q130. - (Topic 5)
In GLBP, which router will respond to client ARP requests?
A. The active virtual gateway will reply with one of four possible virtual MAC addresses.
B. All GLBP member routers will reply in round-robin fashion.
C. The active virtual gateway will reply with its own hardware MAC address.
D. The GLBP member routers will reply with one of four possible burned in hardware addresses.
Answer: A
Explanation:
One disadvantage of HSRP and VRRP is that only one router is in use, other routers must wait for the primary to fail because they can be used. However, Gateway Load Balancing Protocol (GLBP) can use of up to four routers simultaneously. In GLBP, there is still only one virtual IP address but each router has a different virtual MAC address. First a GLBP group must elect an Active Virtual Gateway (AVG). The AVG is responsible for replying ARP requests from hosts/clients. It replies with different virtual MAC addresses that correspond to different routers (known as Active Virtual Forwarders – AVFs) so that clients can send traffic to different routers in that GLBP group (load sharing).