Download CCNA 200-301 Exam Questions and Answers: VLANs, Switching, and EtherChannel and more Exams Computer Networks in PDF only on Docsity!
CCNA 200- 301 EXAM QUESTIONS THE LATEST & UPDATED
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What is the primary purpose of a VLAN? -- Answer โโ To create a broadcast domain; enable segmentation or isolation of broadcast traffic Unassigned Cisco switch ports remain in which VLAN? -- Answer โโ VLAN 1 Do VLANs prevent broadcast storms? -- Answer โโ No, they minimize the size and effect of the broadcast storm on neighbor switches and hosts What are four advantages to using VLANs? -- Answer โโ 1. Enable access to network services based on logical requirements
- Network security is optimized with VLANs that enable managing and filtering sensitive traffic from other network traffic
- Bandwidth efficiency is accomplished through segmenting traffic into smaller broadcast domains
- Easier add/move/delete administration of endpoints on a network and scalability for larger enterprise deployments What is the Layer 2 Broadcast Destination Address? -- Answer โโ FFFF.FFFF.FFFF What is the Layer 3 Broadcast Destination Address? -- Answer โโ 255.255.255. What is VLAN 1 used for and can it be deleted? -- Answer โโ Management Traffic; it cannot be deleted What is the normal VLAN range? -- Answer โโ VLAN 2 - 1001 What is the extended VLAN range? -- Answer โโ VLAN 1006 - 4094
What VLANs are auto-created and cannot be deleted? -- Answer โโ VLAN 1, 1002 - 1005 What VLANs cannot be pruned from a trunk? -- Answer โโ VLAN 1006 - 4094 How many VLANs can be assigned to a switch access port? -- Answer โโ Only one VLAN unless you are connecting an IP phone What commands would you use to setup a switch access port with an IP phone? -- Answer โโ interface <interface#/#> switchport mode access switchport access vlan # switchport voice vlan # Where is the switch VLAN configuration stored? -- Answer โโ vlan.dat file What commands would you use to globally create and name a VLAN? -- Answer โโ vlan # name <name_of_vlan> What is the default switch port mode? -- Answer โโ Access port What will switch access ports do with am Ethernet frame it receives with an 802.1q tag? -- Answer โโ It will discard the packet without learning the source MAC address What command would you use to configure a range of switch ports? -- Answer โโ interface range gigabitethernet#/# - # What command lists all VLANs configured on a switch? -- Answer โโ show vlan or show vlan brief What command is used to display the switch ports assigned to a single VLAN? -- Answer โโ show vlan id
How do you disable MAC address table aging? -- Answer โโ Configure the MAC aging timer to zero What are the steps when a host sends data to a server on the same VLAN for the first time? -- Answer โโ 1. Switch adds the source MAC address of incoming frame if it is not listed in the MAC address table
- Switch does a MAC address table lookup for the destination MAC address
- Switch floods a frame using FFFF.FFFF.FFFF as destination MAC address out all switch ports except the port where the source MAC address was learned
- Server wit the assigned MAC address responds with a frame that lists the MAC address
- Switch updates the MAC address table with the MAC address of the server; That is the destination MAC address for frames sent from the host
- Switch forwards the frames from the host to the server based on the switch port assigned to the server What is Cut-Through Switching? -- Answer โโ It is a technique that optimizes performance by examing only the first 6 bytes (destination MAC address) of an Ethernet frame before making a forwarding decision. The switch does a MAC address table lookup for the destination MAC address and forwards the frame. What is the advantage of Cut-Through Switching? -- Answer โโ The forwarding decision is made before all of the frame arrives and thereby minimizes latency What is Store-and-Forward Switching? -- Answer โโ Traditional switching where the frame is not forwarded until all of the frame has arrived. The switch copies the frame to memory before examining the destination MAC address and forwarding the frame. What is CEF? -- Answer โโ Cisco Express Forwarding: Layer 3 switching technique that creates FIB and adjacency tables for optimized forwarding. It is only available on routers and switch platforms with routing enabled and the required hardware What is an FIB? -- Answer โโ Forwarding Information Base: Used by CEF to mae IP destination prefix-based switching decisions. Conceptually similar to a routing table or information base. It maintains a mirror image of the forwarding information contained in the IP routing table.
Which devices can perform frame rewrite? -- Answer โโ Layer 3 switches and Wireless LAN Controllers Which devices perform frame switching? -- Answer โโ Layer 2 switches and Access Points What are the duplex and speed default settings on a switch port? -- Answer โโ auto- negotiation What is the purpose of a switch trunk? -- Answer โโ To forward multiple VLANs between switches What command enables trunking on an interface? -- Answer โโ switchport mode trunk encapsulation dot1q What does the native VLAN forward? -- Answer โโ Control traffic across switch trunks Why is it recommended to change the native VLAN? -- Answer โโ This is a Cisco security best practice as there are security vulnerabilities associated with default VLAN 1; STP issues are minimized as well by selecting a nondefault VLAN instead of VLAN 1 What command changes the native VLAN? -- Answer โโ switchport trunk native vlan <vlan_id> What is the purpose of VLAN pruning? -- Answer โโ To permit or deny VLANs across a switch trunk What is the Cisco default for VLAN pruning -- Answer โโ To allow all VLANs across the trunk What command sets a range of VLANs to an interface? -- Answer โโ switchport trunk allowed vlan <#>-<#>
What are the advantages of EtherChannels? -- Answer โโ Fault tolerance (redundancy) and high speed connectivity between switches What is the maximum number of ports Cisco switches support to a single EtherChannel bundle? -- Answer โโ 8 ports What is the maximum number of ports LACP supports to a single EtherChannel bundle? -- Answer โโ 16 ports, however only 8 ports can be active simultaneously What is LACP? -- Answer โโ Link Aggregation Control Protocol, within the IEEE specification, provides a method of control the bundling of several physical ports together to form a single logical channel. It allows a network device to negotiate an automatic bundling of links by sending LACP packets to the peer What are the options for configuring an EtherChannel? -- Answer โโ Static or Dynamic Protocols What is the difference between static and dynamic EtherChannel configurations? -- Answer โโ Static does not provide any dynamic trunk negotiation What are the four supported modes of LACP? -- Answer โโ On, off, active, and passive What does the channel-group bind? -- Answer โโ The port channel interface to an EtherChannel What is a Layer 2 port channel? -- Answer โโ Logical interface comprised of EtherChannel access ports or trunk ports How is the Layer 2 port channel created? -- Answer โโ It is created automatically based on the channel-group number What are the supported channel-group numbers? -- Answer โโ 1 - 4096
What is a Layer 3 port channel? -- Answer โโ Routed logical interface comprised of EtherChannel access ports or trunk ports What is Active mode in LACP? -- Answer โโ The active end of the group sends out a LACP frame and initiates the negotiation to form the EtherChannel. Both ends could be active and the result will be the same What is Passive mode in LACP? -- Answer โโ Does not initiate the negotiation, it just responds to LACP packets initiated by the other end. If both ends are passive, the EtherChannel would bot be formed What is PAgP? -- Answer โโ Port Aggregation Protocol: Cisco proprietary networking protocol, which is used for the automated, logical aggregation of Ethernet switch ports What is the default mode for LACP? -- Answer โโ Passive Mode What is the default mode for PAgP? -- Answer โโ Auto Mode What layer of the TCP/IP model does HTTP belong? -- Answer โโ Application Layer What layer of the TCP/IP model does POP3 belong? -- Answer โโ Application Layer What layer of the TCP/IP model does SMTP belong? -- Answer โโ Application Layer What layer of the TCP/IP model does TCP and UDP belong? -- Answer โโ Transport Layer What layer of the TCP/IP model does ICMP belong? -- Answer โโ Internet Layer What does the Application Layer define? -- Answer โโ Does not define the applications itself, but it defines services that applications need. The Application Layer provides an interface between software running on a computer and the network itself. What does the return code 200 mean in an HTTP header? -- Answer โโ OK
What is a Small Form Pluggable (SFP)? -- Answer โโ Replacement for GBICs, used on Gigabit interfaces, with a smaller size, taking less space on the side of the networking card or switch What is a Small Form Pluggable Plus (SFP+)? -- Answer โโ Same size as the SFP, but used on 10-Gbps interfaces How many pairs of wires do the 10BASE-T and 100BASE-T use? -- Answer โโ 2 pairs What pins do Ethernet NIC transmitters use? -- Answer โโ The pair connected to pins 1 and 2 What pins do Ethernet NIC receivers use? -- Answer โโ The pair connected to pins 3 and 6 What pins do Switch transmitters use? -- Answer โโ The pair connected to pins 3 and 6 What pins do Switch receivers use? -- Answer โโ The pair connected to pins 1 and 2 What cable would you use to connect a computer to a switch? -- Answer โโ Straight through cable What devices transmit on pins 3 and 6? -- Answer โโ Switches and Hubs What devices transmit on pins 1 and 2? -- Answer โโ NICs, Routers, APs When would you use a Crossover Cable? -- Answer โโ When the endpoints transmit on the same pair When would you use a Straight through Cable? -- Answer โโ When the endpoints transmit on different pairs
What is auto-mdix? -- Answer โโ In Cisco switches, it notices when the wrong cable is used and automatically changes its login to make it work. What is the maximum length of many UTP-based Ethernet standards? -- Answer โโ 100 meters What are the layers of a fiber cable inside going outward? -- Answer โโ Core, Cladding, Buffer, Strengthener, Outer Jacket What are the layers of a fiber cable outside going in? -- Answer โโ Outer Jacket, Strengthener, Buffer, Cladding, Core What is the light source for a fiber cable? -- Answer โโ Optical Transmitter What is the purpose of the cladding in a fiber cable? -- Answer โโ Reflect light back into the core Which mode of fiber cable has around one-fifth the diameter of the other mode? -- Answer โโ Single-Mode Fiber What type of light source does Multimode Fiber use? -- Answer โโ Light Emitting Diode (LED) What type of light source does Single-Mode Fiber use? -- Answer โโ Laser What distance do standards of 10 Gigabit over Fiber allow? -- Answer โโ 400 meters What does Multimode fiber improve on? -- Answer โโ Improves the maximum distance over UTP and uses less expensive transmitters as compared to single-mode What is the cable type and maximum distance of 10GBASE-S? -- Answer โโ Multimode
- 400 meters What is the cable type and maximum distance of 10GBASE-LX4? -- Answer โโ Multimode - 300 meters
What is the Maximum Transmission Unit (MTU)? -- Answer โโ Defines the maximum Layer 3 packet that can be sent over a medium How many bytes and purpose of the Frame Check Sequence (FCS) in an Ethernet trailer? -- Answer โโ 4 bytes - Provides a method for the receiving NIC to determine whether the frame experienced transmission errors How many bytes are the Ethernet header and trailer? -- Answer โโ Header = 22 + Trailer = 4 == 26 bytes What does the FCS do in the Ethernet Trailer? -- Answer โโ Gives the receiving node a way to compare results with the sender, to discover whether errors occurred in the frame How does the FCS perform in the Ethernet Trailer? -- Answer โโ Sender applies a complex math formula to the frame before sending it, storing the result of the formula in the FCS field. The receiver applies the same formula to the received frame. If the results are different, an error occurred, and the receiver discards the frame What do WAN technologies define? -- Answer โโ The physical (Layer 1) and data link (Layer 2) protocols used to communicate long distances What duplex is a Leased Line link? -- Answer โโ Full-Duplex Why are they called Leased Lines? -- Answer โโ The fact that the telco company does not own the line but instead pays a monthly lease fee to use it What are other names used for Leased Lines? -- Answer โโ Leased Circuit, Circuit, Serial Line, Serial Link, Point-to-point link, Point-to-point line, WAN link What is a Private Line (WAN)? -- Answer โโ A line that data sent over it cannot be copied by other telco customers, so the data is private What is the transmit speed of a T1 line? -- Answer โโ 1.544 Mbps
Where do Telcos put their equipment? -- Answer โโ In buildings called Central Offices (COs) What layer of tranmission service do Leased Lines define? -- Answer โโ Physical (Layer 1); many companies and standards organizations have created data-link protocols to control and use Leased Lines What is the High-Level Data Link Control Protocol? -- Answer โโ Bit-oriented code- transparent synchronous data link layer protocol used for Leased Lines. It performs less work than Ethernet because the frame can only go one place; to the other end of the line. While HDLC has an address field, the destination is implied. What differentiates the HDLC header from ISO to Cisco standard? -- Answer โโ The Cisco standard header has the 'Type' field so routers understand which routing protocol the frame holds What HDLC field is equivalent to the Preamble and SFD fields in an Ethernet Frame? -- Answer โโ Flag What does the Flag do in an HDLC header? -- Answer โโ Lists a recognizable bit pattern s that the receiving nodes realize a new frame is arriving What are the four fields in the Cisco proprietary HDLC header in order? -- Answer โโ Flag, Address, Control, and Type What field(s) are in the HDLC trailer? -- Answer โโ Frame Check Sequence (FCS) What is the PoP? -- Answer โโ Point of Presence: Nearby SP location that connects to the customer building What is EoMPLS? -- Answer โโ Ethernet over Multiprotocol Label Switching, a technology that can be used to create the Ethernet service for a customer How many bytes are in the IP header? -- Answer โโ 20 bytes
What command removes the VLAN configuration details -- Answer โโ delete vlan.dat What is the default aging timer for a MAC Address table? -- Answer โโ 300 seconds What does a switch do when the MAC Address table is full? -- Answer โโ Times out the oldest record in the table What does the login command do on a line interface? -- Answer โโ Tells IOS to enable the user of a single shared password with no username on this line, so that the switch asks the user for the password How do you create local users & associated them to lines? -- Answer โโ 'username password ' 'line #' 'login local' What commands are necessary for ssh? -- Answer โโ 'hostname ' 'ip domain-name ' crypto key generate rsa' What can you add to 'crypto key generate rsa' to set the modulus value? -- Answer โโ 'modulus #' What command would you use to only allow ssh? -- Answer โโ 'transport input ssh' What modulus value should be at least used with sshv2? -- Answer โโ 768 - bit key How do you override default settings of sshv1 support? -- Answer โโ 'ip ssh version 2' What is the SVI? -- Answer โโ Switch Virtual Interface - VLAN interface that acts like the switch's own NIC How do you give an SVI DHCP? -- Answer โโ 'int vlan 1' 'ip address dhcp'
How do you set the history size of only the current session? -- Answer โโ 'terminal history size #' How do you disable uto syslog at console? -- Answer โโ 'no logging console' What subnet mask is considered the serial mask? -- Answer โโ 255.255.255.
