101 · Question #586
Which protocol does an internet host use to request the hardware address of an IP address?
The correct answer is B. Address Resolution Protocol (ARP). ARP is the protocol that resolves a known IP address to an unknown hardware (MAC) address on a local network. This mapping is required before a device can construct a Layer 2 Ethernet frame for a local destination.
Question
Which protocol does an internet host use to request the hardware address of an IP address?
Options
- AReverse Address Resolution Protocol (RARP)
- BAddress Resolution Protocol (ARP)
- CBOOTP
- DDynamic Host Configuration Protocol (DHCP)
How the community answered
(36 responses)- B92% (33)
- C3% (1)
- D6% (2)
Why each option
ARP is the protocol that resolves a known IP address to an unknown hardware (MAC) address on a local network. This mapping is required before a device can construct a Layer 2 Ethernet frame for a local destination.
RARP performs the opposite function - it maps a known MAC address to an unknown IP address - and is now obsolete, replaced by DHCP.
ARP works by broadcasting a request asking which host owns a given IP address, and the owner replies with its MAC address. This IP-to-MAC resolution is performed automatically by the OS before each Layer 2 transmission, making it the correct protocol for obtaining a hardware address from an IP address.
BOOTP is a legacy protocol used to assign IP addresses and boot parameters to diskless clients over the network, not to resolve IP addresses to MAC addresses.
DHCP dynamically assigns IP addresses and network configuration parameters to clients on request, but does not resolve IP addresses to hardware addresses.
Concept tested: ARP IP-to-MAC address resolution process
Source: https://www.cisco.com/c/en/us/support/docs/ip/dynamic-address-allocation-resolution/13718-5.html
Topics
Community Discussion
No community discussion yet for this question.