Why do packets have both IP addresses and MAC addresses on them?

Why do packets have both IP addresses and MAC addresses on them?

So again, IP Addresses are logical and routeable addresses. And that’s why computers have both MAC Addresses and IP Addresses. MAC Addresses handle the physical connection from computer to computer while IP Addresses handle the logical routeable connection from both computer to computer AND network to network.

What are the source and destination MAC address in the Ethernet header of the ARP request frame?

The Ethernet header has the same three parts: a Destination MAC address, a Source MAC address, and an EtherType. The Destination MAC is Host A — the initial requester, and the Source MAC is Host B — the original target. Notice the frame is addressed directly back to Host A – this is what makes the response unicast.

Why does the switch have two MAC addresses assigned?

A MAC Address is given by the manufacturer and it is embedded in the chip that allows your device to connect to a network. For a network switch, it is likely to have many MAC addresses, since one MAC address is assigned to every interface on the switch.

Can a computer have multiple MAC addresses?

No. A MAC is contains a vendor id, model number and serial number so it is unique. Usually the MAC is the Ethernet Adapter so if a machine has multiple adapters it will have multiples MAC. The MAC is usually associated with an IP address.

What is ARP and Mac?

The Address Resolution Protocol (ARP) is a communication protocol used for discovering the link layer address, such as a MAC address, associated with a given internet layer address, typically an IPv4 address. This mapping is a critical function in the Internet protocol suite.

How do switches learn MAC addresses of its connected devices?

A switch builds its MAC address table by recording the MAC address of each device connected to each of its ports. The switch uses the information in the MAC address table to send frames destined for a specific device out the port, which has been assigned to that device.

How does an ARP reply packet get the MAC address?

ARP reply packet is directed to the host, which transmitted the ARP request packet. If a host is not able to get the MAC address of a host, how it knows about its IP address? A host will either use a static file like /etc/hosts or DNS protocol to get the IP address of another host.

Why can’t the MAC address be represented using the IP address?

ARP is extensively used by all the hosts in an Ethernet network. Why a IP address needs to be mapped to a MAC address, why can’t the MAC address itself is represented using the IP address? The length of a MAC address is 6 bytes and the length of an IP address is 4 bytes. Obviously, the MAC address cannot be represented using the IP address.

What happens when a host receives an ARP Request packet?

After the IP address is resolved by the ARP module, the packet is sent to the Ethernet driver for transmission. What happens when a host receives an ARP request packet? The ARP request is received and processed by all the hosts in the network, since it is a broadcast packet.

What happens when the ARP module cannot resolve an IP address?

If the ARP module is not able to find an entry for this IP address in the ARP cache, then it sends an ARP request packet to the Ethernet driver, to resolve the IP address to the Ethernet address. After the IP address is resolved by the ARP module, the packet is sent to the Ethernet driver for transmission.