What is the function of ARP?
- resolves IP addresses to MAC addresses
- resolves host names to IP addresses
- resolves MAC addresses to IP addresses
- resolves port numbers to IP addresses
Address resolution Protocol (ARP) resolves IP addresses to MAC addresses. It uses a broadcast mechanism to learn the MAC address of a host known only by its address. The media access control (MAC) address uniquely identifies a node on a network segment. ARP tables show the relationship of IP addresses to MAC addresses and are located on most devices.
There is no mechanism for translating port numbers to IP addresses. The IP address and port number combination of a source or destination is called a socket.
Domain Name System (DNS) is the service that translates host names to IP addresses. DNS uses UDP when resolution queries are sent to a server by a client, but its uses TCP for zone transfers between DNS servers. According to RFC 1035, UDP is the recommended method for queries. A DNS server provides a centralized database of domain name-to –IP address resolutions on a server that other computers on a network can use for name resolution.
There is currently no service that resolves MAC addresses to IP addresses.
Objective: Network Concepts
Sub-Objective: Describe the operation of these network services: ARP, DNS, DHCP