Module 13: The ARP Process

Which two characteristics describe MAC addresses?

- physical address assigned to the NIC - identifies source and destination in Layer 2 header

What are two functions of MAC addresses in a LAN?

- to allow the transfer of frames from source to destination - to uniquely identify a node on a network

Refer to the exhibit. Host A needs to send data to the server, but does not know its MAC address. When host A sends out an ARP request, what response will be in the ARP reply?

00:0D:00:B4:12:F3

What two protocols are used to determine the MAC address of a known destination device IP address (IPv4 and IPv6)?

ARP and ND

Host-A has an Ethernet frame to send to Host-B on the same network. Host-A knows the IP address of Host-B but not its MAC address. What message will Host-A send to determine the MAC address of Host B?

ARP request

The destination MAC address of an Ethernet broadcast in hexadecimal is:

FFFF.FFFF.FFFF

Which destination address is used in an ARP request frame?

FFFF.FFFF.FFFF

When an Ethernet switch receives a frame that is broadcast, it will:

Forward the frame out all ports except the incoming port

Host-A sends an ARP request and receives an ARP reply from Host-B. What is in the ARP reply that Host-A did not know and needs to communicate with Host-B?

Host B's MAC address

What addresses are mapped by ARP?

IPv4 address to a destination MAC address

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?

PC2 will send an ARP reply with the PC2 MAC address

Refer to the exhibit. Switches Sw1 and Sw2 have MAC address tables that are populated with all the exhibited host MAC addresses. If host H1 sends a frame with destination address FFFF.FFFF.FFFF, what will be the result?

Sw1 will flood the frame out all ports except the inbound port. The frame will be flooded by Sw2 and processed by hosts H2, H3, and H4

Host-B receives an ARP request. Host-B will return an ARP Reply if:

The IP address in the ARP request matches its own IP address

What destination MAC address would be included in a frame sent from a source device to a destination device on the same local network?

The MAC address of the destination device

What destination MAC address would be included in a frame sent from a source device to a destination device on a remote local network?

The MAC address of the local router interface

Which statement describes the treatment of ARP requests on the local link?

They are received and processed by every device on the local network

What statement describes a characteristic of MAC addresses?

They are the physical address of the NIC or interface

An ARP request is sent out as:

a broadcast, so all devices on the same network will receive it

What important information is examined in the Ethernet frame header by a Layer 2 device in order to forward the data onward?

destination MAC address

What is one function of the ARP protocol?

resolving an IPv4 address to a MAC address