4-IP Services_14548706_2023_01_05_20_24

अब Quizwiz के साथ अपने होमवर्क और परीक्षाओं को एस करें!

Question 1 Which command can you enter to allow Telnet to be supported in addition to SSH? A. transport input telnet ssh B. transport input telnet C. no transport input telnet D. privilege level 15

Question 1 Which statement about the nature of NAT overload is true? A. applies a one-to-many relationship to internal IP addresses B. applies a one-to-one relationship to internal IP addresses (static nat) C. applies a many-to-many relationship to internal IP addresses (dynamic nat - NAT Pool) D. can be configured only on Gigabit interface

Question 4 Which function does an SNMP agent perform? A. It sends information about MIB variables in response to requests from the NMS B. It coordinates user authentication between a network device and a TACACS+ or RADIUS server C. It requests information from remote network nodes about catastrophic system events. D. It manages routing between Layer 3 devices in a network

Question 6 Which type of information resides on a DHCP server? A. a list of the available IP addresses in a pool B. a list of public IP addresses and their corresponding names C. usernames and passwords for the end users in a domain D. a list of statically assigned MAC addresses

Question 7 What is a DHCP client? A. a host that is configured to request an IP address automatically B. a router that statically assigns IP addresses to hosts C. a server that dynamically assigns IP addresses to hosts D. a workstation that requests a domain name associated with its IP address

Question 7 Which technology must be implemented to configure network device monitoring with the highest security? A. SNMPv3 B. IP SLA C. NetFlow D. syslog

Question 9 What is the purpose of configuring different levels of syslog for different devices on the network? A. to rate-limit messages for different severity levels from each device B. to set the severity of syslog messages from each device C. to identify the source from which each syslog message originated D. to control the number of syslog messages from different devices that are stored locally

A HSRP Questions Premium Member: You can test your knowledge with these questions first via this link (via HTML). Note: If you are not sure about HSRP, please read our HSRP tutorial.

Question 2 Which command enables a router to become a DHCP client? A. ip address dhcp B. ip helper-address C. ip dhcp pool D. ip dhcp client

A Explanation If we want to get an IP address from the DHCP server on a Cisco device, we can use the command "ip address dhcp". Note: The command "ip helper-address" enables a router to become a DHCP Relay Agent.

Question 5 What does traffic shaping do to reduce congestion in a network? A. buffers and queues packets B. buffers without queuing packets C. queues without buffering packets D. drops packets

A Explanation The following diagram illustrates the key difference between traffic policing and traffic shaping. Traffic policing propagates bursts. When the traffic rate reaches the configured maximum rate (or committed information rate), excess traffic is dropped (or remarked). The result is an output rate that appears as a saw-tooth with crests and troughs. In contrast to policing, traffic shaping retains excess packets in a queue and then schedules the excess for later transmission over increments of time. The result of traffic shaping is a smoothed packet output rate. Note: Committed information rate (CIR): The minimum guaranteed data transfer rate agreed to by the routing device.

Question 132 Which QoS traffic handling technique retains excess packets in a queue and reschedules these packets for later transmission when the configured maximum bandwidth has been surpassed? A. traffic shaping B. traffic policing C. weighted random early detection D. traffic prioritization

A Explanation + Shaping: retains excess packets in a queue and then schedules the excess for later transmission over increments of time. When traffic reaches the maximum configured rate, additional packets are queued instead of being dropped to proceed later. Traffic shaping is applicable only on outbound interfaces as buffering and queuing happens only on outbound interfaces. Shaping is configured in bits per second.

Question 14 A network administrator must enable DHCP services between two sites. What must be configured for the router to pass DHCPDISCOVER messages on to the server? A. a DHCP Relay Agent B. DHCP Binding C. a DHCP Pool D. DHCP Snooping

A Explanation If the DHCP Server is not on the same subnet with the DHCP Client, we need to configure the router on the DHCP client side to act as a DHCP Relay Agent so that it can forward DHCP messages between the DHCP Client & DHCP Server. To make a router a DHCP Relay Agent, simply put the "ip helper- address <IP-address-of-DHCP-Server>" command under the interface that receives the DHCP messages from the DHCP Client. As we know, router does not forward broadcast packets (it drops them instead) so DHCP messages like DHCPDISCOVER message will be dropped. But with the "ip helper-address ..." command, the router will accept that broadcast message and cover it into a unicast packet and forward it to the DHCP Server. The destination IP address of the unicast packet is taken from the "ip helper-address ..." command.

Question 31 When a client and server are not on the same physical network, which device is used to forward requests and replies between client and server for DHCP? A. DHCP relay agent B. DHCP server C. DHCPDISCOVER D. DHCPOFFER

Question 10 Which command must you enter to configure a DHCP relay? A. ip helper-address B. ip address dhcp C. ip dhcp relay D. ip dhcp pool

Question 50 What is a characteristic of private IPv4 addressing? A. used without tracking or registration B. issued by IANA in conjunction with an autonomous system number C. traverse the Internet when an outbound ACL is applied D. composed of up to 65,536 available addresses

A Explanation Only private address of class A (10.0.0.0 - 10.255.255.255) includes 16,777,216 so answer D is not correct.

Question 5 Refer to the exhibit. Router R1 is configured with static NAT. Addressing on the router and the web server are correctly configured, but there is no connectivity between the web server and users on the Internet. What is a possible reason for this lack of connectivity? A. The router NAT configuration has an incorrect inside local address B. The inside global address is incorrect C. The NAT configuration on interface S0/0/1 is incorrect. D. Interface Fa0/0 should be configured with the command ip nat outside

A Explanation The "ip nat inside" command was wrongly configured with inside local address of 192.168.11.254 while it should be 192.168.11.11, which is the IP address of the web server.

Question 1 Which command must you enter to guarantee that an HSRP router with higher priority becomes the HSRP primary router after it is reloaded? A. standby 10 preempt B. standby 10 version 1 C. standby 10 priority 150 D. standby 10 version 2

A Explanation The "preempt" command enables the HSRP router with the highest priority to immediately become the active router.

Question 11 In QoS, which prioritization method is appropriate for interactive voice and video? A. expedited forwarding B. traffic policing C. round-robin scheduling D. low-latency queuing

A Explanation The Expedited Forwarding (EF) model is used to provide resources to latency (delay) sensitive real- time, interactive traffic.

Question 41 When DHCP is configured on a router, which command must be entered so the default gateway is automatically distributed? A. default-router B. default-gateway C. ip helper-address D. dns-server

A Explanation The following example shows how to configure a DHCP Server on a Cisco router: Configuration Description Router(config)#ip dhcp pool CLIENTS Create a DHCP Pool named CLIENTS Router(dhcp- config)#network 10.1.1.0 /24 Specifies the subnet and mask of the DHCP address pool Router(dhcp- config)#default- router 10.1.1.1 Set the default gateway of the DHCP Clients Router(dhcp-config)#dns- server 10.1.1.1 Configure a Domain Name Server (DNS) Router(dhcp- config)#domain-name 9tut.com Configure a domain-name Router(dhcp-config)#lease 0 12 Duration of the lease (the time during which a client computer can use an assigned IP address). The syntax is "lease {days[hours] [minutes] | infinite}". In this case the lease is 12 hours. The default is a one-day lease. Before the lease expires, the client typically needs to renew its address lease assignment with the server Router(dhcp-config)#exit Router(config)# ip dhcp excluded-address 10.1.1.1 10.1.1.10 The IP range that a DHCP Server should not assign to DHCP Clients. Notice this command is configured under global configuration mode

Question 18 What is a capability of FTP in network management operations? A. uses separate control and data connections to move files between server and client B. devices are directly connected and use UDP to pass file information C. encrypts data before sending between data resources D. offers proprietary support at the session layer when transferring data

A Explanation There are actually two ports associated with FTP: TCP 20 and 21. FTP creates a virtual connection over TCP port 21 for control information, and then it creates a separate TCP connection on port 20 for data transfers. Reference: Cisco Secure Internet Security Solutions Book

Question 72 Refer to the exhibit. Which router or router group are NTP clients? A. R1, R2, and R3 B. R1 C. R2 and R3 D R1, R3, and R4

A Explanation To configure the NTP client on a Cisco device we use the ntp server {ip-address} command in global configuration. Syslog Questions January 15th, 2021Go to comments Premium Member: You can test your knowledge with these questions first via this link (via HTML). Note: If you are not sure about Syslog, please read our Syslog tutorial.

Question 3 A Cisco IP phone receive untagged data traffic from an attached PC. Which action is taken by the phone? A. It allows the traffic to pass through unchanged B. It drops the traffic C. It tags the traffic with the default VLAN D. It tags the traffic with the native VLAN

A Explanation Untagged traffic from the device attached to the Cisco IP Phone passes through the phone unchanged, regardless of the trust state of the access port on the phone. Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst2960/software/release/12- 2_40_se/configuration/guide/scg/swvoip.pdf

Question 3 Which MAC address is recognized as a VRRP (là 1 giao thức giống hệt HSRP ở phiên bản chuẩn mở còn HSRP là chuẩn riêng của Cisco) virtual address? A. 0000.5E00.010a B. 0005.3711.0975 C. 0000.0C07.AC99 D. 0007.C070.AB01

A Explanation With VRRP, the virtual router's MAC address is 0000.5E00.01xx , in which xx is the VRRP group

Question 4 Which two outcomes are predictable behaviors for HSRP? (Choose two) A. The two routers share a virtual IP address that is used as the default gateway for devices on the LAN B. The two routers negotiate one router as the active router and the other as the standby router C. Each router has a different IP address both routers act as the default gateway on the LAN, and traffic is load balanced between them D. The two routers synchronize configurations to provide consistent packet forwarding E. The two routed share the same IP address, and default gateway traffic is load-balanced between them

A B

Question 1 What are two roles of Domain Name Services (DNS)? (Choose two) A. enables applications to identify resources by name instead of IP address B. allows a single host name to be shared across more than one IP address C. improves security by protecting IP addresses under Fully Qualified Domain Names (FQDNs) D. builds a flat structure of DNS names for more efficient IP operations E. encrypts network traffic as it travels across a WAN by default

A B Explanation An example of DNS is described below: When you attempt to go to a domain name such as 9tut.com, your browser will instruct your computer to do a DNS lookup on that domain name. This DNS lookup will query a DNS resolver (for example Google at 8.8.8.8). Once the resolver responds, the computer will usually choose the first IP in the response and use that for the connection. In the case of multiple IP addresses, the DNS server will respond with multiple IP addresses and the first IP will usually be used for the request. Due to how most DNS resolvers work, the order of IP addresses usually changes for each request.

Question 5 What are two differences between optical-fiber cabling and copper cabling? (Choose two) A. Light is transmitted through the core of the fiber B. A BNC connector is used for fiber connections C. The glass core component is encased in a cladding D. Fiber connects to physical interfaces using RJ-45 connections E. The data can pass through the cladding

A C Explanation The two main elements of an optical fiber are its core and cladding. The "core", or the axial part of the optical fiber made of silica glass, is the light transmission area of the fiber. It may sometimes be treated with a "doping" element to change its refractive index and therefore the velocity of light down the fiber. The "cladding" is the layer completely surrounding the core. Reference: https://www.cisco.com/c/en/us/products/collateral/interfaces-modules/transceiver- modules/white_paper_c11-463661.html

Question 43 What are two features of the DHCP relay agent? (Choose two) A. minimizes the necessary number of DHCP servers B. assigns DNS locally and then forwards request to DHCP server C. is configured under the Layer 3 interface of a router on the client subnet D. allows only MAC-to-IP reservations to determine the local subnet of a client E. permits one IP helper command under an individual Layer 3 interface

A C Explanation With the DHCP relay agent, we can configure DHCP servers in different subnet of the DHCP client. Otherwise we have to place one DHCP server in the same subnet of DHCP clients -> Answer A is correct. Note: We can configure more than one ip helper command under one Layer 3 interface: To make a router a DHCP Relay Agent, simply put the "ip helper-address <IP-address-of-DHCP- Server>" command under the interface that receives the DHCP messages from the DHCP Client -> Answer C is correct. Miscellaneous Questions

Question 3 What are two roles of the Dynamic Host Configuration Protocol (DHCP)? (Choose two) A. The DHCP server offers the ability to exclude specific IP addresses from a pool of IP addresses B. The DHCP client can request up to four DNS server addresses C. The DHCP server assigns IP addresses without requiring the client to renew them D. The DHCP server leases client IP addresses dynamically E. The DHCP client maintains a pool of IP addresses it can assign

A D

Question 3 Which two QoS tools can provide congestion management? (Choose two) A. CBWFQ B. FRTS C. CAR D. PQ E. PBR (policy based routing)

A D Explanation This module discusses the types of queueing and queueing-related features (such as bandwidth management) which constitute the congestion management QoS features: Class-based WFQ (CBWFQ): extends the standard WFQ functionality to provide support for user- defined traffic classes. For CBWFQ, you define traffic classes based on match criteria including protocols, access control lists (ACLs), and input interfaces. Packets satisfying the match criteria for a class constitute the traffic for that class. Priority queueing (PQ): With PQ, packets belonging to one priority class of traffic are sent before all lower priority traffic to ensure timely delivery of those packets. Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_conmgt/configuration/xe-3s/qos- conmgt-xe-3s-book/qos-conmgt-oview.html Note: Committed Access Rate (CAR) is only used for bandwidth limitation by dropping excessive traffic.

Question 3 Which two tasks must be performed to configure NTP to a trusted server in client mode on a single network device? (Choose two) A. Enable NTP authentication B. Verify the time zone C. Disable NTP broadcasts D. Specify the IP address of the NTP server E. Set the NTP server private key

A D Explanation To configure authentication, perform this task in privileged mode: Step 1: Configure an authentication key pair for NTP and specify whether the key will be trusted or untrusted. Step 2: Set the IP address of the NTP server and the public key. Step 3: Enable NTP client mode. Step 4: Enable NTP authentication. Step 5: Verify the NTP configuration. Reference: https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst4000/8- 2glx/configuration/guide/ntp.html Note: A trusted NTP server may or may not require a secret key so it is not a "must" in this question.

Question 2 Which two actions are performed by the Weighted Random Early Detection mechanism? (Choose two) A. It drops lower-priority packets before it drops higher-priority packets B. It can identify different flows with a high level of granularity C. It guarantees the delivery of high-priority packets D. It can mitigate congestion by preventing the queue from filling up E. It supports protocol discovery

A D Explanation Weighted Random Early Detection (WRED) is just a congestion avoidance mechanism. WRED drops packets selectively based on IP precedence. Edge routers assign IP precedences to packets as they enter the network. When a packet arrives, the following events occur: 1. The average queue size is calculated. 2. If the average is less than the minimum queue threshold, the arriving packet is queued. 3. If the average is between the minimum queue threshold for that type of traffic and the maximum threshold for the interface, the packet is either dropped or queued, depending on the packet drop probability for that type of traffic. 4. If the average queue size is greater than the maximum threshold, the packet is dropped. WRED reduces the chances of tail drop (when the queue is full, the packet is dropped) by selectively dropping packets when the output interface begins to show signs of congestion (thus it can mitigate congestion by preventing the queue from filling up). By dropping some packets early rather than waiting until the queue is full, WRED avoids dropping large numbers of packets at once and minimizes the chances of global synchronization. Thus, WRED allows the transmission line to be used fully at all times. WRED generally drops packets selectively based on IP precedence. Packets with a higher IP precedence are less likely to be dropped than packets with a lower precedence. Thus, the higher the priority of a packet, the higher the probability that the packet will be delivered (-> answer A is correct). Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/qos_conavd/configuration/15-mt/qos- conavd-15-mt-book/qos-conavd-cfg-wred.html

Question 33 What is a DNS lookup operation? A. serves requests over destination port 53 B. DNS server pings the destination to verify that it is available C. DNS server forwards the client to an alternate IP address when the primary IP is down D. responds to a request for IP address to domain name resolution to the DNS server

A Explanation An example of DNS is described below: When you attempt to go to a domain name such as 9tut.com, your browser will instruct your computer to do a DNS lookup on that domain name. This DNS lookup will query a DNS resolver (for example Google at 8.8.8.8). Once the resolver responds, the computer will usually choose the first IP in the response and use that for the connection. The most frequently used port for DNS is UDP 53 but as time progresses, DNS will reply on TCP Port 53 more heavily.

Question 116 Which QoS per-hop behavior changes the value of the ToS field in the IPv4 packet header? A. shaping B. marking C. policing D. classification

Question 26 What is a benefit of VRRP? A. It provides traffic load balancing to destinations that are more than two hops from the source. B. It provides the default gateway redundancy on a LAN using two or more routers. C. It allows neighbors to share routing table information between each other. D. It prevents loops in a Layer 2 LAN by forwarding all traffic to a root bridge, which then makes the final forwarding decision.

Question 4 Which option is the main function of congestion management? A. discarding excess traffic B. queuing traffic based on priority C. classifying traffic D. providing long-term storage of buffered data

Question 8 Where does the configuration reside when a helper address is configured to support DHCP? A. on the switch trunk interface. B. on the router closest to the client. C. on the router closest to the server. D. on every router along the path.

Question 2 A network engineer must back up 20 network router configurations globally within a customer environment. Which protocol allows the engineer to perform this function using the copy function? A. COP B. SNMP C. SMTP D. ARP

B Explanation SNMP is an application-layer protocol that provides a message format for communication between SNMP managers and agents. SNMP provides a standardized framework and a common language used for the monitoring and management of devices in a network. The SNMP framework has three parts: + An SNMP manager + An SNMP agent + A Management Information Base (MIB) The Management Information Base (MIB) is a virtual information storage area for network management information, which consists of collections of managed objects. With SNMP, the network administrator can send commands to multiple routers to do the backup.

Question 17 Which protocol requires authentication to transfer a backup configuration file from a router to a remote server? A. TFTP B. FTP C. DTP D. SMTP

B Explanation The FTP protocol requires a client to send a remote username and password on each FTP request to a server.When you copy a configuration file from the router to a server using FTP, the Cisco IOS software sends the first valid username it encounters in the following list: 1. The username specified in the copy privileged EXEC command,if a username is specified. 2. The username set by the ip ftp username global configuration command, if the command is configured. 3. Anonymous. Reference: https://www.cisco.com/c/en/us/td/docs/ios-xml/ios/sys-image-mgmt/configuration/xe-16- 7/sysimgmgmt-xe-16-7-book/sysimgmgmt-ftp.pdf

Question 38 Refer to the exhibit. The ntp server 192.168.0.3 command has been configured on Router1 to make it an NTP client of router 2. Which command must be configured on Router2 so that it operates in server-only mode and relies only on its internal clock? A. Router2(config)#ntp passive B. Router2(config)#ntp master 4 C. Router2(config)#ntp server 172.17.0.1 D. Router2(config)#ntp server 192.168.0.2

B Explanation An Authoritative NTP Server can distribute time even when it is not synchronized to an existing time server. To configure a Cisco device as an Authoritative NTP Server, use the ntp master [stratum] command.

Question 8 A network analyst is tasked with configuring the date and time on a router using EXEC mode.The date must be set to January 1,2020 and the time must be set to 12:00 am.what command should be used? A. clock summer-time date B. clock set C. clock timezone D. clock summer-time recurring

B Explanation In this example, the clock time is set to 12:00 am with the clock date of January 1,2020. R1#clock set 12:00:00 jan 1 2020

Question 56 When deploying a new network that includes both Cisco and third-party network devices, which redundancy protocol avoids the interruption of network traffic if the default gateway router fails? A. FHRP B. VRRP C. HSRP D. GLBP

B Explanation Only VRRP is an open standard protocol. DNS Questions January 10th, 2021Go to comments Premium Member: You can test your knowledge with these questions first via this link (via HTML).

Question 67 Which QoS queuing method discards or marks packets that exceed the desired bit rate of traffic flow? A. shaping B. policing C. CBWFQ D. LLQ

B Explanation Policing: is used to control the rate of traffic flowing across an interface. During a bandwidth exceed (crossed the maximum configured rate), the excess traffic is generally dropped or remarked.

Question 7 What is the purpose of traffic shaping? A. be a marking mechanism that identifies different flows B. to limit the bandwidth that a flow can use to C. to provide fair queuing for buffered flows D. to mitigate delays over slow links

B Explanation The primary reasons you would use traffic shaping are to control access to available bandwidth, to ensure that traffic conforms to the policies established for it, and to regulate the flow of traffic in order to avoid congestion that can occur when the sent traffic exceeds the access speed of its remote, target interface.

Question 79 Which DSCP per-hop forwarding behavior is divided into subclasses based on drop probability? A. class-selector B. assured C. expedited D. default

B Explanation The term Per-Hop Behaviour (PHB) refers to how a node will treat traffic having the same Differentiated Services Code Point (DSCP) values. Assured Forwarding has four standard classes from AF1 to AF4. It is important to note that the class number does not determine priority. Each class is treated independently and placed into different queues. Each AF class has its own IP Precedence with three drop probabilities, low, medium, and high. Reference: https://www.routeprotocol.com/dscp-per-hop-behaviour-assured-forwarding/ DHCP Questions January 7th, 2021Go to comments Premium Member: You can test your knowledge with these questions first via this link (via HTML).

Question 126 Refer to the exhibit. Users on existing VLAN 100 can reach sites on the Internet. Which action must the administrator take to establish connectivity to the Internet for users in VLAN 200? A. Define a NAT pool on the router. B. Update the NAT INSIDF RANGFS ACL C. Configure the ip nat outside command on another interface for VLAN 200 D. Configure static NAT translations for VLAN 200

B Explanation We need to add the "permit 10.10.20.0 0.0.0.255" command to the ACL.

Question 42 Refer to the exhibit. What is the next step to complete the implementation for the partial NAT configuration shown? A. Reconfigure the static NAT entries that overlap the NAT pool B. Configure the NAT outside interface C. Modify the access list for the internal network on e0/1 D. Apply the ACL to the pool configuration

B Explanation We see the line "Outside interfaces: " is still empty which means we have not configured an outside interface yet. NTP Questionss January 16th, 2021Go to comments Premium Member: You can test your knowledge with these questions first via this link (via HTML). NTP master <stratum> (đóng vai trò như 1 ntp server cho các thiết bị khác đồng bộ thời gian tới). - NTP is designed to synchronize the time on a network. NTP runs over the User Datagram Protocol (UDP), using port 123 as both the source and destination. - An Authoritative NTP Server can distribute time even when it is not synchronized to an existing time server. To configure a Cisco device as an Authoritative NTP Server, use the ntp master [stratum] command. - To configure the local device to use a remote NTP clock source, use the command ntp server <IP address>. For example: Router(config)#ntp server 192.168.1.1 - The ntp authenticate command is used to enable the NTP authentication feature (NTP authentication is disabled by default). - The ntp trusted-key command specifies one or more keys that a time source must provide in its NTP packets in order for the device to synchronize to it. This command provides protection against accidentally synchronizing the device to a time source that is not trusted. - The ntp authentication-key defines the authentication keys. The device does not synchronize to a time source unless the source has one of these authentication keys and the key number is specified by the ntp trusted-key number command. - Two most popular commands to display time sources statistics: show ntp status and show ntp associations

Question 3 What facilitates a Telnet connection between devices by entering the device name? A. SNMP B. DNS lookup C. syslog D. NTP

B Explanation Your router can be configured to use DNS lookups if we wish to use the ping or traceroute commands with a host name rather than an IP address. For example: Then we can Telnet or ping to it: Reference: https://www.cisco.com/c/en/us/support/docs/ip/domain-name-system-dns/24182- reversedns.html Note: In the above example, 10.10.10.1 is not the IP address of www.cisco.com. This IP address is just the DNS Name Server to resolve "www.cisco.com" to the public IP address "198.133.219.25". Note: By default, any single word entered on an IOS device that is not recognized as a valid command is treated as a hostname to which you want to telnet. The device will try to translate that word to an IP address in a process that can last about a minute. Consider the following example: In the output above we typed an unrecognized command "test". The router entered the DNS resolution process which lasted about a minute. This can be annoying and this is why this feature is often turned off, especially in the lab environments. If you don't need to have a DNS server configured for your router, you can use the "no ip domain- lookup" command to disable the DNS translation process: Now, if I mistype a command, the router will not perform a DNS resolution process:

Question 4 Refer to the exhibit. An engineer deploys a topology in which R1 obtains its IP configuration from DHCP. If the switch and DHCP server configurations are complete and correct. Which two sets of commands must be configured on R1 and R2 to complete the task? (Choose two) A. R1 (config)# interface fa0/0 R1 (config-if)# ip helper-address 198.51.100.100 B. R2(config)# interface gi0/0 R2(config-if)# ip helper-address 198.51.100.100 C. R1 (config)# interface fa0/0 R1 (config-if)# ip address dhcp R1 (config-if)# no shutdown D. R2(config)# interface gi0/0 R2(config-if)# ip address dhcp E. R1 (config)# interface fa0/0 R1 (config-if)# ip helper-address 192.0.2.2

B C

Question 2 Which two pieces of information can you determine from the output of the show ntp status command? (Choose two) A. whether the NTP peer is statically configured B. the IP address of the peer to which the clock is synchronized C. the configured NTP servers D. whether the clock is synchronized E. the NTP version number of the peer

B D Explanation Below is the output of the "show ntp status" command. From this output we learn that R1 has a stratum of 10 and it is getting clock from 10.1.2.1.

Question 1 Which two QoS tools are used to guarantee minimum bandwidth to certain traffic? (Choose two) A. FIFO (no QOS) B. CBWFQ C. LLC D. WFQ E. RSVP

B D Explanation First-in, first-out (FIFO): FIFO entails no concept of priority or classes of traffic. With FIFO, transmission of packets out the interface occurs in the order the packets arrive, which means no QoS Weighted fair queueing (WFQ): offers dynamic, fair queuing that divides bandwidth across queues of traffic based on weights. In standard WFQ, packets are classified into flows according to one of four criteria: the source Internet Protocol address (IP address), the destination IP address, the source Transmission Control Protocol (TCP) or User Datagram Protocol (UDP) port, or the destination TCP or UDP port. Class-based weighted fair queueing (CBWFQ) extends the standard WFQ functionality to provide support for user-defined traffic classes. For CBWFQ, you define traffic classes based on match criteria including protocols, access control lists (ACLs), and input interfaces. Packets satisfying the match criteria for a class constitute the traffic for that class. A queue is reserved for each class, and traffic belonging to a class is directed to the queue for that class. Once a class has been defined according to its match criteria, you can assign it characteristics. To characterize a class, you assign it bandwidth, weight, and maximum packet limit. The bandwidth assigned to a class is the guaranteed bandwidth delivered to the class during congestion. The Resource Reservation Protocol (RSVP) protocol allows applications to reserve bandwidth for their data flows. It is used by a host, on the behalf of an application data flow, to request a specific amount of bandwidth from the network. RSVP is also used by the routers to forward bandwidth reservation requests.

Question 1 Loging trap "severity level" - logging trap 5 (từ 0-5) Logging trap warning (log ra từ 0-4) What will happen if you configure the logging trap debug (logging trap 7) command on a router? Default: 0-6 A. It causes the router to send messages with lower severity levels to the syslog server B. It causes the router to send all messages with the severity levels Warning, Error, Critical, and Emergency to the syslog server C. It causes the router to send all messages to the syslog server D. It causes the router to stop sending all messages to the syslog server

Question 108 Refer to the exhibit. An engineer is configuring a new router on the network and applied this configuration. Which additional configuration allows the PC to obtain its IP address from a DHCP server? A. Configure the ip dhcp relay information command under interface Gi0/1 B. Configure the ip dhcp smart-relay command globally on the router C. Configure the ip helper-address 172.16.2.2 command under interface Gi0/0 D. Configure the ip address dhcp command under interface Gi0/0

Question 23 Which type of address is shared by routers in a HSRP implementation and used by hosts on the subnet as their default gateway address? A. multicast address B. loopback IP address C. virtual IP address D. broadcast address

Question 74 Refer to the exhibit. How should the configuration be updated to allow PC1 and PC2 access to the Internet? A. Modify the configured number of the second access list B. Remove the overload keyword from the ip nat inside source command C. Add either the ip nat {inside|outside} command under both interfaces D. Change the ip nat inside source command to use interface GtgabitEthernet0/0

Question 34 Which QoS tool can you use to optimize voice traffic on a network that is primarily intended for data traffic? A. WRED B. FIFO C. PQ D.WFQ

C Explanation With Priority Queueing (PQ), traffic is classified into high, medium, normal, and low priority queues. The high priority traffic is serviced first, then medium priority traffic, followed by normal and low priority traffic. -> Therefore we can assign higher priority for voice traffic. Also with PQ, higher priority traffic can starve the lower priority queues of bandwidth. No bandwidth guarantees are possible -> It is still good because this network is mostly used for data traffic so voice traffic amount is small. With First In First Out (FIFO) or Weighted Fair Queueing (WFQ), there is no priority servicing so they are not suitable here. Reference: https://www.cisco.com/c/en/us/td/docs/ios/solutions_docs/qos_solutions/QoSVoIP/QoSVo IP.html Weighted Random Early Detection (WRED) is just a congestion avoidance mechanism. WRED measures the size of the queues depending on the Precedence value and starts dropping packets when the queue is between the minimum threshold and the maximum threshold -> It does not have priority servicing either.

Question 2 If a notice-level messaging is sent to a syslog server, which event has occurred? A. A network device has restarted B. An ARP Inspection has failed C. A routing instance has flapped D A debug operation is running.

C Explanation Usually no action is required when a route flaps so it generates the notification syslog level message (level 5).

Question 2 Which command must be present in a Cisco Device configuration to enable the device to resolve an FQDN? A. ip host B. ip name-server C. ip domain-lookup D. ip domain-name

C Explanation FQDN stands for Fully Qualified Domain Name. The FQDN represents the absolute address of the internet presence. "Fully qualified" refers to the unique identification that guarantees that all of the domain levels are specified. The FQDN contains the host name and domain, including the top level domain, and can be uniquely assigned to an IP address. For example: R1.9tut.com. The command "ip domain-lookup" enables DNS-based host name-to-address translation. This command is enabled by default.

Question 1 Which feature or protocol determines whether the QoS on the network is sufficient to support IP services? A. LLDP B. CDP C. IP SLA D. EEM

C Explanation IP SLA allows an IT professional to collect information about network performance in real time. Therefore it helps determine whether the QoS on the network is sufficient for IP services or not. Cisco IOS Embedded Event Manager (EEM) is a powerful and flexible subsystem that provides real- time network event detection and onboard automation. It gives you the ability to adapt the behavior of your network devices to align with your business needs.

Question 3 What event has occurred if a router sends a notice level message to a syslog server? A. A TCP connection has been torn down B. An ICMP connection has been built C. An interface line has changed status D. A certificate has expired

C Explanation If you used to configure a Cisco device then maybe you saw this notice level message: Number 5 in the above message represents for the Notification Level (Normal, but significant, conditions exist).

Question 2 Refer to the exhibit. An engineer configured NAT translations and has verified that the configuration is correct. Which IP address is the source IP? R1#show ip nat translations Pro Inside global Inside local Outside local Outside global tcp 172.23.104.3:43268 10.4.4.4:43268 172.23.103.10:23 172.23.103.10:23 tcp 172.23.104.4:45507 10.4.4.5:45507 172.23.103.10:80 172.23.103.10:80 A. 10.4.4.4 B. 10.4.4.5 C. 172.23.103.10 D. 172.23.104.4

C Explanation Maybe this question wanted to ask "which IP address is the source IP at the receiving side?" as there are two correct answers for inside local IP address (10.4.4.4 & 10.4.4.5) so they cannot be the correct answer.

Question 4 Which type of address is the public IP address of a NAT device? A. outside global B. outside local C. inside global D. inside local E. outside public F. inside public

C Explanation NAT use four types of addresses: * Inside local address - The IP address assigned to a host on the inside network. The address is usually not an IP address assigned by the Internet Network Information Center (InterNIC) or service provider. This address is likely to be an RFC 1918 private address. * Inside global address - A legitimate IP address assigned by the InterNIC or service provider that represents one or more inside local IP addresses to the outside world. * Outside local address - The IP address of an outside host as it is known to the hosts on the inside network. * Outside global address - The IP address assigned to a host on the outside network. The owner of the host assigns this address.

Question 28 An engineering team asks an implementer to configure syslog for warning conditions and error conditions. Which command does the implementer configure to achieve the desired result? A. logging trap 2 B. logging trap 3 C. logging trap 4 D. logging trap 5

C Explanation Syslog levels are listed below Level Keyword Description 0 emergencies System is unusable 1 alerts Immediate action is needed 2 critical Critical conditions exist 3 errors Error conditions exist 4 warnings Warning conditions exist 5 notification Normal, but significant, conditions exist 6 informational Informational messages 7 debugging Debugging messages The highest level is level 0 (emergencies). The lowest level is level 7. If we configure syslog level 4 then it will send all the syslog messages from level 0 to 4.

Question 82 How does TFTP operate in a network? A. relies on the well-known TCP port 20 to transmit data B. requires two separate connections for control and data traffic C. uses block numbers to identify and mitigate data-transfer errors D. provides secure data transfer

C Explanation TFTP is a simple protocol for transferring files, implemented on top of the UDP/IP protocols using well- known port number 69. Each file block has an identification number so that ACK messages from target devices can correctly report back to sending devices if a block is received successfully. Reference: https://www.ipswitch.com/blog/what-is-tftp-trivial-file-transfer-protocol

Question 6 An engineer is configuring NAT to translate the source subnet of 10.10.0.0/24 to any of three addresses 192.168.3.1, 192.168.3.2, 192.168.3.3. Which configuration should be used? Option A: Option B: Option C: enable enable enable configure terminal configure terminal configure terminal ip nat pool mypool ip nat pool mypool ip nat pool mypool 192.168.3.1 192.168.3.3 192.168.3.1 192.168.3.3 192.168.3.1 192.168.3.3 prefix-length 30 prefix-length 30 prefix-length 30 route-map permit 10.10.0.0 access-list 1 permit access-list 1 permit 255.255.255.0 10.10.0.0 0.0.0.255 10.10.0.0 0.0.0.255 ip nat outside destination list ip nat outside destination list ip nat inside source list 1 1 pool mypool 1 pool mypool pool mypool interface g1/1 interface g1/1 interface g1/1 ip nat inside ip nat inside ip nat inside interface g1/2 interface g1/2 interface g1/2 ip nat outside ip nat outside ip nat outside A. Option A B. Option B C. Option C

C Explanation The command "ip nat inside source list 1 pool mypool" (notice the keyword "inside", not "outside"). This command translates all source addresses that pass access list 1, which means a source address from 10.10.0.0/24, into an address from the pool named mypool (the pool contains addresses from 192.168.3.1 to 192.168.3.3).

Question 33 Which global command encrypt all passwords in the running configuration? A. enable secret B. enable password-encryption C. service password-encryption D. password-encrypt

C Explanation The service password-encryption command will encrypt all current and future passwords so any password existed in the configuration will be encrypted.

Question 45 How does QoS optimize voice traffic? A. reducing bandwidth usage B. by reducing packet loss C. by differentiating voice and video traffic D. by increasing jitter

C Explanation With Priority Queueing (PQ) in QoS, traffic is classified into high, medium, normal, and low priority queues. The high priority traffic is serviced first, then medium priority traffic, followed by normal and low priority traffic. -> Therefore we can assign higher priority for voice traffic.

Question 92 Which two actions are taken as the result of traffic policing? (Choose two) A. bursting B. fragmentation C. dropping D. remarking E. buffering

C D Explanation Policing: is used to control the rate of traffic flowing across an interface. During a bandwidth exceed (crossed the maximum configured rate), the excess traffic is generally dropped or remarked. The result of traffic policing is an output rate that appears as a saw-tooth with crests and troughs. Traffic policing can be applied to inbound and outbound interfaces. Unlike traffic shaping, QoS policing avoids delays due to queuing. Policing is configured in bytes. QoS Traffic Shaping do not support Marking or Remarking again. This is done only with Traffic Policing. Reference: https://ipcisco.com/lesson/policing-and-shaping/ Note: In policing, remarking the packets that exceed the CIR is an alternative to simply dropping them.

Question 23 Which two QoS tools provides congestion management? (Choose two) A. FRTS B. CAR C. PQ D. PBR E. CBWFQ

C E

Question 9 When implementing a router as a DHCP server, which two features must be configured? (Choose two) A. relay agent information B. database agent C. address pool D. smart-relay E. manual bindings

C E Explanation The following example shows how to configure a DHCP Server on a Cisco router: Configuration Description Router(config)#ip dhcp pool CLIENTS Create a DHCP Pool named CLIENTS Router(dhcp- config)#network 10.1.1.0 /24 Specifies the subnet and mask of the DHCP address pool Router(dhcp- config)#default-router 10.1.1.1 Set the default gateway of the DHCP Clients Router(dhcp-config)#dns- server 10.1.1.1 Configure a Domain Name Server (DNS) Router(dhcp- config)#domain-name 9tut.com Configure a domain-name Router(dhcp-config)#lease 0 12 Duration of the lease (the time during which a client computer can use an assigned IP address). The syntax is "lease {days[hours] [minutes] | infinite}". In this case the lease is 12 hours. The default is a one-day lease. Before the lease expires, the client typically needs to renew its address lease assignment with the server Router(dhcp-config)#exit Router(config)# ip dhcp excluded-address 10.1.1.1 10.1.1.10 The IP range that a DHCP Server should not assign to DHCP Clients. Notice this command is configured under global configuration mode Manual bindings are IP addresses that have been manually mapped to the MAC addresses of hosts that are found in the DHCP database. All DHCP clients send a client identifier (DHCP option 61) in the DHCP packet. To configure manual bindings, you must enter the client-identifier DHCP pool configuration command with the appropriate hexadecimal values identifying the DHCP client. For example: Therefore two requirements for DHCP binding is the IP address and the hardware address (MAC address) of the client. Notice that in the above example "aabb.cc00.0300" is the MAC address of the client while prefix "01" represents the Ethernet media type. Note: In fact, this question should ask "When implementing a router as a DHCP server, which one of these features must be configured?". Because we only need to configure either an "address pool" or "manual binding".

Question 29 Which condition must be met before an NMS handles an SNMP trap from an agent? A. The NMS must be configured on the same router as the SNMP agent B. The NMS must receive a trap and an inform message from the SNMP agent within a configured interval C. The NMS software must be loaded with the MIB associated with the trap D. The NMS must receive the same trap from two different SNMP agents to verify that it is reliable

C chọn lại B

Question 14 What is a syslog facility? A. host that is configured for the system to send log messages B. password that authenticates a Network Management System to receive log messages C. group of log messages associated with the configured severity level D. set of values that represent the processes that can generate a log message

C chọn lại D Explanation Facility levels and syslog levels are different. The purpose of using the facilities is to organize the syslog messages received on the Syslog server from different sources. The default syslog facility setting is local7. Reference: https://www.oreilly.com/library/view/cisco-ios-cookbook/0596527225/ch18s08.html

Question 1 Which Cisco IOS command will indicate that interface GigabitEthernet 0/0 is configured via DHCP? A. show ip interface GigabitEthernet 0/0 dhcp B. show interface GigabitEthernet 0/0 C. show ip interface dhcp D. show ip interface GigabitEthernet 0/0 E. show ip interface GigabitEthernet 0/0 brief

Question 21 Which command creates a static NAT binding for a PC address of 10.1.1.1 to the public routable address 209.165.200.225 assigned to the PC? A. R1(config)#ip nat outside source static 209.165.200.225 10.1.1.1 B. R1(config)#ip nat inside source static 209.165.200.225 10.1.1.1 C. R1(config)#ip nat outside source static 10.1.1.1 209.165.200.225 D. R1(config)#ip nat inside source static 10.1.1.1 209.165.200.225

Question 27 Which protocol does an IPv4 host use to obtain a dynamically assigned IP address? A. ARP B. DNS C. CDP D. DHCP

Question 35 On workstations running Microsoft Windows, which protocol provides the default gateway for the device? A. STP B. DNS C. SNMP D. DHCP

Question 5 How does HSRP provide first hop redundancy? A. It load-balances traffic by assigning the same metric value to more than one route to the same destination in the IP routing table B. It load-balances Layer 2 traffic along the path by flooding traffic out all interfaces configured with the same VLAN C. It forwards multiple packets to the same destination over different routed links and data path D. It uses a shared virtual MAC and a virtual IP address to a group of routers that serve as the default gateway for hosts on a LAN

Question 6 What is the primary purpose of a First Hop Redundancy Protocol? (Tên gọi chung của các giao thức HSRP, VRRP, GLBP - Dự phòng cho DFGW) A. It allows directly connected neighbors to share configuration information B. It allows a router to use bridge priorities to create multiple loop-free paths to a single destination C. It reduces routing failures by allowing Layer 3 load balancing between OSPF neighbors that have the same link metric D. It reduces routing failures by allowing more than one router to represent itself, as the default gateway of a network

Question 86 An engineer is configuring switch SW1 to act as an NTP server when all upstream NTP server connectivity fails. Which configuration must be used? A. SW1# config t SW1(config)#ntp server 192.168.1.1 SW1(config)#ntp access-group server accesslist1 B. SW1# config t SW1(config)3 ntp peer 192.168.1.1 SW1(config)#ntp access-group peer accesslist1 C. SW1# config t SW1(config)#ntp backup SW1(config)#ntp server 192.168.1.1 D. SW1# config t SW1(config)#ntp master SW1(config)#ntp server 192.168.1.1

Question 9 What is the benefit of using FHRP? A. balancing traffic across multiple gateways in proportion to their loads B. reduced management overhead on network routers C. reduced ARP traffic on the network D. higher degree of availability

Question 2 Which command should you enter to verify the priority of a router in an HSRP group? A. show hsrp B. show sessions C. show interfaces D. show standby

D Explanation Below is an example of the "show standby" command: We can see the current HSRP priority of this device, which is 90 and the configured HSRP priority too (which is 90, too).

Question 79 What is the purpose of the ip address dhcp command? A. to configure an interface as a DHCP server B. to configure an interface as a DHCP relay C. to configure an interface as a DHCP helper D. to configure an interface as a DHCP client

D Explanation Use the ip address dhcp command to obtain IP address information for the configured interface.

Question 40 Which is a fact related to FTP? A. It uses block numbers to identify and mitigate data-transfer errors B. It always operates without user authentication C. It relies on the well-known UDP port 69. D. It uses two separate connections for control and data traffic

D Explanation FTP communicates using two TCP connections. Control traffic is exchanged over TCP/21, and data transmission is performed over TCP/20.

Question 4 What is a purpose of traffic shaping? A. It enables dynamic flow identification. B. It enables policy-based routing. C. It provides best-effort service. D. It limits bandwidth usage.

D Explanation + Shaping: retains excess packets in a queue and then schedules the excess for later transmission over increments of time. When traffic reaches the maximum configured rate, additional packets are queued instead of being dropped to proceed later. Traffic shaping is applicable only on outbound interfaces as buffering and queuing happens only on outbound interfaces. Shaping is configured in bits per second. Best Effort Service means a service on a shared network in which the network does not provide any guarantee that data is delivered or that delivery meets any quality of service, meaning that the services obtain unspecified variable bit rate, latency and packet loss, depending on the current traffic load -> Traffic shaping does not drop packets so it does not offer best effort service -> Answer C is not correct. The primary reasons you would use traffic shaping are to control access to available bandwidth, to ensure that traffic conforms to the policies established for it, and to regulate the flow of traffic in order to avoid congestion that can occur when the sent traffic exceeds the access speed of its remote, target interface -> Answer D is correct.

Question 6 A device detects two stations transmitting frames at the same time. This condition occurs after the first 64 bytes of the frame is received interface counter increments? A. collision B. runt C. CRC D. late collision

D Explanation A late collision is defined as any collision that occurs after the first 512 bits (or 64th byte) of the frame have been transmitted. The usual possible causes are full-duplex/half-duplex mismatch, exceeded Ethernet cable length limits, or defective hardware such as incorrect cabling, non-compliant number of hubs in the network, or a bad NIC. Late collisions should never occur in a properly designed Ethernet network. They usually occur when Ethernet cables are too long or when there are too many repeaters in the network. Reference: https://www.cisco.com/en/US/docs/internetworking/troubleshooting/guide/tr1904.html

Question 3 Which keyword in a NAT configuration enables the use of one outside IP address for multiple inside hosts? A. source B. static C. pool D. overload

D Explanation By adding the keyword "overload" at the end of a NAT statement, NAT becomes PAT (Port Address Translation). This is also a kind of dynamic NAT that maps multiple private IP addresses to a single public IP address (many-to-one) by using different ports. Static NAT and Dynamic NAT both require a one-to-one mapping from the inside local to the inside global address. By using PAT, you can have thousands of users connect to the Internet using only one real global IP address. PAT is the technology that helps us not run out of public IP address on the Internet. This is the most popular type of NAT. An example of using "overload" keyword is shown below: R1(config)# ip nat inside source list 1 interface ethernet1 overload

Question 4 How does a router behave when configured with the default DNS lookup settings, and a URL is entered on the CLI? A. prompts the user to specify the desired IP address. B. initiates a ping request to the URL. C. continuously attempts to resolve the URL until the command is cancelled. D. attempts to query a DNS server on the network.

D Explanation By default, domain lookup function is enabled on the router so it treats every unrecognized command as a hostname, attempts to make a telnet connection to that which, in turn, attempts to resolve a hostname to IP address by querying the DNS server. Here is a typical sample. R1#xyz Translating "xyz"...domain server (255.255.255.255) Translating "xyz"...domain server (255.255.255.255) (255.255.255.255) Translating "xyz"...domain server (255.255.255.255) % Unknown command or computer name, or unable to find computer address Note: In order to save some time we can disable DNS lookup by the "no ip domain lookup" global command.

Question 78 Refer to the exhibit. Which command set configures ROUTER-1 to allow Internet access for users on the 192.168.1.0/24 subnet while using 209.165.202.129 for Port Address Translation? A. ip nat pool CCNA 192.168.0.0 192.168.1.255 netmask 255.255.255.0 access-list 10 permit 192.168.0.0 0.0.0.255 ip nat inside source list 10 pool CCNA overload B. ip nat pool CCNA 209.165.202.129 209.165.202.129 netmask 255.255.255.255 access-list 10 permit 192.168.1.0 255.255.255.0 ip nat inside source list 10 pool CCNA overload C. ip nat pool CCNA 192.168.0.0 192.168.1.255 netmask 255.255.255.0 access-list 10 permit 192.168.0.0 255.255.255.0 ip nat inside source list 10 pool CCNA overload D. ip nat pool CCNA 209.165.202.129 209.165.202.129 netmask 255.255.255.255 access-list 10 permit 192.168.1.0 0.0.0.255 ip nat inside source list 10 pool CCNA overload

D Explanation By providing only one IP address in the pool CCNA, we are sure that IP address will be used for Internet with PAT.

Question 18 Refer to the exhibit. The given Windows PC is requesting the IP address of the host at www.cisco.com. To which IP address is the request sent? A. 19e.168.1.226 B. 192.168.1.253 C. 192.168.1.100 D. 192.168.1.254

D Explanation From the output we see the line "DHCP Server ...: 192.168.1.254" so this is the IP address the request is sent. Notice that the "Default Gateway" IP address is in the same subnet of DHCP Server so the PC can directly send request to the DHCP Server. QoS Questions January 10th, 2021Go to comments QoS quick summary: 1. Network factors: + Bandwidth: the speed of the link (or the capacity available on the link), usually measured in bits per second (bps) + Delay (or latency): how long a packet takes to get from the sender to the receiver. The more the delay, the slower the network. Delay is usually measured in milliseconds (ms) + Jitter: A measure of the variation in delay between packets. For example, one packet need 50ms to reach B from A while another packet takes 40ms then the jitter is 10ms + Loss: When packets travels to the destination, some of them may get lost. 2. QoS Models: + Best Effort: No QoS policies applied + Integrated Services (IntServ): Resource Reservation Protocol (RSVP) is used to reserve bandwidth + Differentiated Services (DiffServ): Packets are classified and marked individually; policy decisions are made independently by each node in a path. 3. QoS Markings: + IP Precedence: The first three bits of the IP ToS field (8 traffic classes) + Differentiated Service Code Point (DSCP): The first six bits of the IP ToS are used to provide granular classification 4. QoS terms: + Tail drop: When the queue is full, the packet is dropped. This is the default behavior. + Policing: is used to control the rate of traffic flowing across an interface. During a bandwidth exceed (crossed the maximum configured rate), the excess traffic is generally dropped or remarked. The result of traffic policing is an output rate that appears as a saw- tooth with crests and troughs. Traffic policing can be applied to inbound and outbound interfaces. Unlike traffic shaping, QoS policing avoids delays due to queuing. Policing is configured in bytes. + Shaping: retains excess packets in a queue and then schedules the excess for later transmission over increments of time. When traffic reaches the maximum configured rate, additional packets are queued instead of being dropped to proceed later. Traffic shaping is applicable only on outbound interfaces as buffering and queuing happens only on outbound interfaces. Shaping is configured in bits per second. The primary reasons you would use traffic shaping are to control access to available bandwidth, to ensure that traffic conforms to the policies established for it, and to regulate the flow of traffic in order to avoid congestion that can occur when the sent traffic exceeds the access speed of its remote, target interface. + Marking: allows you to mark (set or change) a value (attribute) for the traffic belonging to a specific class 5. Congestion Management (types of queuing): uses the marking on each packet to determine which queue to place packets in First-in, first-out (FIFO): FIFO entails no concept of priority or classes of traffic. With FIFO, transmission of packets out the interface occurs in the order the packets arrive, which means no QoS Priority Queuing (PQ): schedules traffic such that the higher-priority queues "always" get serviced first Custom Queuing (CQ): provide specific traffic guaranteed bandwidth at a potential congestion point, assuring the traffic a fixed portion of available bandwidth and leaving the remaining bandwidth to other traffic. Weighted fair queueing (WFQ): allocates bandwidths to flows based on the weight. In addition, to allocate bandwidths fairly to flows, WFQ schedules packets in bits (not bytes). This prevents long packets from preempting bandwidths of short packets and reduces the delay and jitter when both short and long packets wait to be forwarded. Class-based weighted fair queueing (CBWFQ) extends the standard WFQ functionality to provide support for user-defined traffic classes. For CBWFQ, you define traffic classes based on match criteria including protocols, access control lists (ACLs), and input interfaces. Packets satisfying the match criteria for a class constitute the traffic for that class. A queue is reserved for each class, and traffic belonging to a class is directed to the queue for that class. Once a class has been defined according to its match criteria, you can assign it characteristics. To characterize a class, you assign it bandwidth, weight, and maximum packet limit. The bandwidth assigned to a class is the guaranteed bandwidth delivered to the class during congestion. The Resource Reservation Protocol (RSVP) protocol allows applications to reserve bandwidth for their data flows. It is used by a host, on the behalf of an application data flow, to request a specific amount of bandwidth from the network. RSVP is also used by the routers to forward bandwidth reservation requests. Premium Member: You can test your knowledge with these questions first via this link (via HTML).

Question 3 A network analyst is tasked with configured the date and time on a router using EXEC mode. The date must be set to 12:00am. Which command should be used? A. Clock timezone B. Clock summer-time-recurring C. Clock summer-time date D. Clock set

D Explanation In this example, the clock time is set to 12:00 am with the clock date of January 1, 2020. R1#clock set 12:00:00 jan 1 2020

Question 33 Which command implies the use of SNMPv3? A. snmp-server community B. snmp-server host C. snmp-server enable traps D. snmp-server user

D Explanation Only SNMPv3 requires to add a SNMP user to a group to work. Note: "community" string is the password which is used in SNMPv1 & v2. "snmp-server host" command can be used by both SNMPv2 & v3.

Question 52 Which QoS feature drops traffic that exceeds the committed access rate? A. weighted fair queuing B. FIFO C. shaping D. policing

D Explanation Policing: is used to control the rate of traffic flowing across an interface. During a bandwidth exceed (crossed the maximum configured rate), the excess traffic is generally dropped or remarked.

Question 7 When the active router in an HSRP group fails, what router assumes the role and forwards packets? A. listening B. backup C. forwarding D. standby

D Explanation Standby router is backup when active router fails by monitoring periodic hellos sent by the active router (multicast to 224.0.0.2, UDP port 1985) to detect a failure of the active router.

Question 19 What is a feature of TFTP? A. provides secure data transfer B. relies on the well-known TCP port 20 to transmit data C. uses two separate connections for control and data traffic D. offers anonymous user login ability

D Explanation TFTP is a simple protocol for transferring files, implemented on top of the UDP/IP protocols using well- known port number 69 -> Answer A and answer B are not correct. TFTP has no session control -> Answer C is not correct.

Question 11 Why was the RFC 1918 address space defined? A. preserve public IPv6 address space B. support the NAT protocol C. reduce instances of overlapping IP addresses D. conserve public IPv4 addressing

D Explanation The RFC 1918 is Address Allocation for Private Internets, which reserves IP addresses for private and internal use. These addresses can be used for networks that do not need to connect to the Internet.

Question 6 Which feature can you implement to reserve bandwidth for VoIP calls across the call path? A. round robin B. CBWFQ C. PQ D. RSVP

D Explanation The Resource Reservation Protocol (RSVP) protocol allows applications to reserve bandwidth for their data flows. It is used by a host, on the behalf of an application data flow, to request a specific amount of bandwidth from the network. RSVP is also used by the routers to forward bandwidth reservation requests.

Question 1 Which level of severity must be set to get informational syslogs? A. alert B. critical C. notice D. debug

D Explanation The Syslog levels are: Level Keyword Description 0 emergencies System is unusable 1 alerts Immediate action is needed 2 critical Critical conditions exist 3 errors Error conditions exist 4 warnings Warning conditions exist 5 notification Normal, but significant, conditions exist 6 informational Informational messages 7 debugging Debugging messages If you specify a level, that level and all the higher levels will be displayed. Therefore in order to receive informational syslog we must set to level 6 or level 7.

Question 12 An engineer is configuring data and voice services to pass through the same port. The designated switch interface fastethernet0/1 must transmit packets using the same priority for data when they are received from the access port of the IP phone. Which configuration must be used? A. interface fastethernet0/1 switchport priority extend cos 7 B. interface fastethernet0/1 switchport voice vlan untagged C. interface fastethernet0/1 switchport voice vlan dot1p D. interface fastethernet0/1 switchport priority extend trust

D Explanation The command "switchport priority extend cos 7" sets the IP phone port to override the priority received from the PC or the attached device (7 is the highest priority). The command "switchport priority extend trust" tells the Cisco IP Phone to trust the CoS value of the connected PC without remark all packets sent form PC to CoS 0, by default.

Question 92 R1 as an NTP server must have: * NTP authentication enabled * NTP packets sourced from Interface loopback 0 * NTP stratum 2 * NTP packets only permitted to client IP 209.165.200.225 How should R1 be configured? Option A ntp authenticate ntp authentication-key 2 sha1 CISCO123 ntp source Loopback0 ntp access-group server-only 10 ntp master 2 ! access-list 10 permit udp host 209.165.200.225 any eq 123 Option B ntp authenticate ntp authentication-key 2 md5 CISCO123 ntp source Loopback0 ntp access-group server-only 10 ntp stratum 2 ! access-list 10 permit udp host 209.165.200.225 any eq 123 Option C Option D ntp authenticate ntp authentication-key 2 md5 CISCO123 ntp interface Loopback0 ntp access-group server-only 10 ntp stratum 2 ! access-list 10 permit 209.165.200.225 ntp authenticate ntp authentication-key 2 md5 CISCO123 ntp source Loopback0 ntp access-group server-only 10 ntp master 2 ! access-list 10 permit 209.165.200.225 A. Option A B. Option B C. Option C D. Option D

D Explanation To configure a Cisco device as an Authoritative NTP Server, use the ntp master [stratum] command - > Only Option A and Option D are correct. ACL 10 is a standard ACL so we cannot configure protocol (UDP in this case) for the ACL. We can only configure source IP address -> Option D is correct.

Question 1 Which command should you enter to configure a device as an NTP server? A. ntp server B. ntp peer C. ntp authenticate D. ntp master

D Explanation To configure a Cisco device as an Authoritative NTP Server, use the ntp master [stratum] command. To configure a Cisco device as a NTP client, use the command ntp server <IP address>. For example: Router(config)#ntp server 192.168.1.1. This command will instruct the router to query 192.168.1.1 for the time.

Question 21 What does a router do when configured with the default DNS lookup settings, and a URL is entered on the CLI? A. initiates a ping request to the URL B. prompts the user to specify the desired IP address C. continuously attempts to resolve the URL until the command is cancelled D. sends a broadcast message in an attempt to resolve the URL

D Explanation With default DNS lookup settings, the router will sends broadcast message to resolve an URL. Consider the following example: In the output above we typed an unrecognized command "test". The router entered the DNS resolution process which lasted about a minute. Explanation The switch with lowest Bridge Priority would become the root bridge for that VLAN. In this case Switch 2 has the lowest Bridge Priority of 24586 so it will become the root bridge.

Question 13 When deploying syslog, which severity level logs informational message? A. 0 B. 2 C. 4 D. 6

D Syslog levels are listed below Level Keyword Description 0 emergencies System is unusable 1 alerts Immediate action is needed 2 critical Critical conditions exist 3 errors Error conditions exist 4 warnings Warning conditions exist 5 notification Normal, but significant, conditions exist 6 informational Informational messages 7 debugging Debugging messages The highest level is level 0 (emergencies). The lowest level is level 7. By default, the router will send informational messages (level 6). That means it will send all the syslog messages from level 0 to 6.

Question 8 What are two benefits of FHRPs? (Choose two) A. They prevent loops in the Layer 2 network. B. They allow encrypted traffic. C. They are able to bundle multiple ports to increase bandwidth D. They enable automatic failover of the default gateway. E. They allow multiple devices to serve as a single virtual gateway for clients in the network

D E

Question 17 Which two features introduced in SNMPv2 provides the ability to retrieve large amounts of data in one request? (Choose two) A. Get B. GetNext C. Set D. GetBulk E. Inform

D E Explanation The two additional messages are added in SNMP2 (compared to SNMPv1) GetBulkRequest The GetBulkRequest message enables an SNMP manager to access large chunks of data. GetBulkRequest allows an agent to respond with as much information as will fit in the response PDU. Agents that cannot provide values for all variables in a list will send partial information. InformRequest The InformRequest message allows NMS stations to share trap information. (Traps are issued by SNMP agents when a device change occurs.) InformRequest messages are generally used between NMS stations, not between NMS stations and agents.

Question 12 What is the purpose of using First Hop Redundancy Protocol in a specific subnet? A. forwards multicast hello messages between routers B. sends the default route to the hosts on a network C. filter traffic based on destination IP addressing D. ensures a loop-free physical topology

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