7.5 Module Practice and Quiz
What are the two sizes (minimum and expected maximum) of an Ethernet frame? (Choose two.) - 64 bytes - 56 bytes - 1024 bytes - 1518 bytes - 128 bytes
- 64 bytes - 1518 bytes Topic 7.1.0 - The minimum Ethernet frame is 64 bytes. The maximum expected Ethernet frame is 1518 bytes. A network technician must know the minimum and expected maximum frame size in order to recognize runt and jumbo frames.
Which two functions or operations are performed by the MAC sublayer? (Choose two.) - It adds a header and trailer to form an OSI Layer 2 PDU. - It is responsible for Media Access Control. - It adds control information to network protocol layer data. - It performs the function of NIC driver software. - It handles communication between upper and lower layers.
- It adds a header and trailer to form an OSI Layer 2 PDU. - It is responsible for Media Access Control. Topic 7.1.0 - The MAC sublayer is the lower of the two data link sublayers and is closest to the physical layer. The two primary functions of the MAC sublayer are to encapsulate the data from the upper layer protocols and to control access to the media.
Which function or operation is performed by the LLC sublayer? - It communicates with upper protocol layers. - It adds a header and trailer to a packet to form an OSI Layer 2 PDU. - It performs data encapsulation. - It is responsible for media access control.
- It communicates with upper protocol layers. Topic 7.1.0 - The Ethernet LLC sublayer has the responsibility to handle communication between the upper layers and the lower layers of the protocol stack. The LLC is implemented in software and communicates with the upper layers of the application to transition the packet to the lower layers for delivery.
Which two characteristics describe Ethernet technology? (Choose two.) - It uses unique MAC addresses to ensure that data is sent to the appropriate destination. - It is supported by IEEE 802.3 standards. - It typically uses an average of 16 Mbps for data transfer rates. - It is supported by IEEE 802.5 standards. - It uses a ring topology.
- It uses unique MAC addresses to ensure that data is sent to the appropriate destination. - It is supported by IEEE 802.3 standards. Topic 7.1.0 - The 802.3 Ethernet standard specifies that a network implement the CSMA/CD access control method. Each node on the network has a unique MAC address for communication purposes.
What will a host on an Ethernet network do if it receives a frame with a unicast destination MAC address that does not match its own MAC address? - It will discard the frame. - It will remove the frame from the media. - It will forward the frame to the next host. - It will strip off the data-link frame to check the destination IP address.
- It will discard the frame. Topic 7.3.0 - In an Ethernet network, each NIC in the network checks every arriving frame to see if the destination MAC address in the frame matches its own MAC address. If there is no match, the device discards the frame. If there is a match, the NIC passes the frame up to the next OSI layer.
Which statement is true about MAC addresses? - MAC addresses are implemented by software. - The ISO is responsible for MAC addresses regulations. - The first three bytes are used by the vendor assigned OUI. - A NIC only needs a MAC address if connected to a WAN.
- The first three bytes are used by the vendor assigned OUI. Topic 7.2.0 - A MAC address is composed of 6 bytes. The first 3 bytes are used for vendor identification and the last 3 bytes must be assigned a unique value within the same OUI. MAC addresses are implemented in hardware. A NIC needs a MAC address to communicate over the LAN. The IEEE regulates the MAC addresses.
What happens to runt frames received by a Cisco Ethernet switch? - The frame is broadcast to all other devices on the same network. - The frame is dropped. - The frame is returned to the originating network device. - The frame is sent to the default gateway.
- The frame is dropped. Topic 7.1.0 - In an attempt to conserve bandwidth and not forward useless frames, Ethernet devices drop frames that are considered to be runt (less than 64 bytes) or jumbo (greater than 1500 bytes) frames.
What statement describes a characteristic of MAC addresses? - They are only routable within the private network. - They have a 32-bit binary value. - They must be globally unique. - They are added as part of a Layer 3 PDU.
- They must be globally unique. Topic 7.2.0 - Any vendor selling Ethernet devices must register with the IEEE to ensure the vendor is assigned a unique 24-bit code, which becomes the first 24 bits of the MAC address. The last 24 bits of the MAC address are generated per hardware device. This helps to ensure globally unique addresses for each Ethernet device.
What is auto-MDIX? - an Ethernet connector type - a feature to automatically determine speed and duplex - a type of Cisco switch - a feature that detects Ethernet cable type
- a feature that detects Ethernet cable type Topic 7.4.0 - Auto-MDIX is a feature that is enabled on the latest Cisco switches and that allows the switch to detect and use whatever type of cable is attached to a specific port.
What type of address is 01-00-5E-0A-00-02? - an address that reaches one specific host - an address that reaches a specific group of hosts - an address that reaches every host inside a local subnet - an address that reaches every host in the network
- an address that reaches a specific group of hosts Topic 7.2.0 - The multicast MAC address is a special value that begins with 01-00-5E in hexadecimal. It allows a source device to send a packet to a group of devices.
Which network device has the primary function to send data to a specific destination based on the information found in the MAC address table? - switch - modem - hub - router
- switch Topic 7.3.0 - If a MAC address is found in the MAC address table, then data is sent to the associated switch port. If the MAC address is not found in the MAC address table, the data is sent to all switch ports that have devices attached to the same network.
Which network device makes forwarding decisions based on the destination MAC address that is contained in the frame? - router - hub - repeater - switch
- switch Topic 7.3.0 - Switches are the central connection point for a LAN and they maintain a MAC address table. The MAC address table has a port number associated with a MAC address for each particular device. The switch inspects a frame to look at the destination MAC address. The switch then looks in its MAC address table and if that MAC address is found, the switch forwards the data to the port that is associated with that particular MAC address.
What addressing information is recorded by a switch to build its MAC address table? - the destination Layer 2 address of outgoing frames - the source Layer 3 address of outgoing packets - the destination Layer 3 address of incoming packets - the source Layer 2 address of incoming frames
- the source Layer 2 address of incoming frames Topic 7.3.0 - A switch builds a MAC address table by inspecting incoming Layer 2 frames and recording the source MAC address found in the frame header. The discovered and recorded MAC address is then associated with the port used to receive the frame.
What is the special value assigned to the first 24 bits of a multicast MAC address transporting an IPv4 packet? 01-00-5E FF-FF-FF FF-00-5E 01-5E-00
01-00-5E Topic 7.2.0 - Just as with multicast IP addresses, there is a special assigned value for multicast MAC addresses. The first 24 bits are set in hex to: 01-00-5E. The remaining 6 hex digits are derived from the lower 23 bits of the IP multicast.
