ITN Chapter 5
2 What are the two sizes (minimum and maximum) of an Ethernet frame? (Choose two.) 128 bytes 56 bytes 1024 bytes 64 bytes 1518 bytes
64 bytes 1518 bytes The minimum Ethernet frame is 64 bytes. The maximum Ethernet frame is 1518 bytes. A network technician must know the minimum and maximum frame size in order to recognize runt and jumbo frames.
8 Which destination address is used in an ARP request frame? FFFF.FFFF.FFFF 0.0.0.0 127.0.0.1 01-00-5E-00-AA-23 255.255.255.255
FFFF.FFFF.FFFF The purpose of an ARP request is to find the MAC address of the destination host on an Ethernet LAN. The ARP process sends a Layer 2 broadcast to all devices on the Ethernet LAN. The frame contains the IP address of the destination and the broadcast MAC address, FFFF.FFFF.FFFF.
17 Refer to the exhibit. A switch with a default configuration connects four hosts. The ARP table for host A is shown. What happens when host A wants to send an IP packet to host D? Host D sends an ARP request to host A. Host A sends out the packet to the switch. The switch sends the packet only to the host D, which in turn responds. Host A sends an ARP request to the MAC address of host D. Host A sends out a broadcast of FF:FF:FF:FF:FF:FF. Every other host connected to the switch receives the broadcast and host D responds with its MAC address.
Host A sends out a broadcast of FF:FF:FF:FF:FF:FF. Every other host connected to the switch receives the broadcast and host D responds with its MAC address. Whenever the destination MAC address is not contained within the ARP table of the originating host, the host (host A in this example) will send a Layer 2 broadcast that has a destination MAC address of FF:FF:FF:FF:FF:FF. All devices on the same network receive this broadcast. Host D will respond to this broadcast.
3 What statement describes Ethernet? It defines the most common LAN type in the world. It defines a standard model used to describe how networking works. It is the required Layer 1 and 2 standard for Internet communication. It connects multiple sites such as routers located in different countries.
It defines the most common LAN type in the world. Ethernet is the most common LAN protocol in the world. It operates at Layer 1 and 2, but is not required for Internet communication. The OSI model is used to describe how networks operate. A WAN connects multiple sites located in different countries.
15 The ARP table in a switch maps which two types of address together? Layer 2 address to a Layer 4 address Layer 3 address to a Layer 4 address Layer 4 address to a Layer 2 address Layer 3 address to a Layer 2 address
Layer 3 address to a Layer 2 address The switch ARP table keeps a mapping of Layer 2 MAC addresses to Layer 3 IP addresses. These mappings can be learned by the switch dynamically through ARP or statically through manual configuration.
4 Which two statements describe features or functions of the logical link control sublayer in Ethernet standards? (Choose two.) The LLC sublayer is responsible for the placement and retrieval of frames on and off the media. The LLC sublayer adds a header and a trailer to the data. Logical link control is specified in the IEEE 802.3 standard. Logical link control is implemented in software. The data link layer uses LLC to communicate with the upper layers of the protocol suite.
Logical link control is implemented in software. The data link layer uses LLC to communicate with the upper layers of the protocol suite. Logical link control is implemented in software and enables the data link layer to communicate with the upper layers of the protocol suite. Logical link control is specified in the IEEE 802.2 standard. IEEE 802.3 is a suite of standards that define the different Ethernet types. The MAC (Media Access Control) sublayer is responsible for the placement and retrieval of frames on and off the media. The MAC sublayer is also responsible for adding a header and a trailer to the network layer protocol data unit (PDU).
16 Refer to the exhibit. PC1 issues an ARP request because it needs to send a packet to PC2. In this scenario, what will happen next? SW1 will send an ARP reply with its Fa0/1 MAC address. RT1 will send an ARP reply with its Fa0/0 MAC address. SW1 will send an ARP reply with the PC2 MAC address. PC2 will send an ARP reply with its MAC address. RT1 will send an ARP reply with the PC2 MAC address.
PC2 will send an ARP reply with its MAC address. When a network device wants to communicate with another device on the same network, it sends a broadcast ARP request. In this case, the request will contain the IP address of PC2. The destination device (PC2) sends an ARP reply with its MAC address.
7 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. 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.
1 What happens to runt frames received by a Cisco Ethernet switch? The frame is returned to the originating network device. The frame is dropped. The frame is sent to the default gateway. The frame is broadcast to all other devices on the same network.
The frame is dropped. 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.
6 What statement describes a characteristic of MAC addresses? They are only routable within the private network. They must be globally unique. They have a 32-bit binary value. They are added as part of a Layer 3 PDU.
They must be globally unique. 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.
18 Refer to the exhibit. The switches are in their default configuration. Host A needs to communicate with host D, but host A does not have the MAC address for its default gateway. Which network hosts will receive the ARP request sent by host A? only hosts A, B, and C only hosts A, B, C, and D only router R1 only hosts B and C only hosts B, C, and router R1 only host D
only hosts B, C, and router R1 Since host A does not have the MAC address of the default gateway in its ARP table, host A sends an ARP broadcast. The ARP broadcast would be sent to every device on the local network. Hosts B, C, and router R1 would receive the broadcast. Router R1 would not forward the message.
9 What addressing information is recorded by a switch to build its MAC address table? the source Layer 3 address of outgoing packets the destination Layer 2 address of outgoing frames the destination Layer 3 address of incoming packets the source Layer 2 address of incoming frames
the source Layer 2 address of incoming frames 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.
21 What is the aim of an ARP spoofing attack? to associate IP addresses to the wrong MAC address to overwhelm network hosts with ARP requests to flood the network with ARP reply broadcasts to fill switch MAC address tables with bogus addresses
to associate IP addresses to the wrong MAC address In an ARP spoofing attack, a malicious host intercepts ARP requests and replies to them so that network hosts will map an IP address to the MAC address of the malicious host.
14 True or False? When a device is sending data to another device on a remote network, the Ethernet frame is sent to the MAC address of the default gateway.
true A MAC address is only useful on the local Ethernet network. When data is destined for a remote network of any type, the data is sent to the default gateway device, the Layer 3 device that routes for the local network.
