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What is RARP?
RARP (Reverse Address Resolution Protocol) defined in RFC 903 is used to map MAC addresses to IP addresses in a TCP/IP network.
Contrary to popular belief, RARP is not used for "pure" communication. In a RARP request, the same MAC address is typically written as both the requester and the respondent MAC address, indicating that the primary purpose of RARP is to determine the local machine's IP address.
On the other hand, only the IP address of that machine will be known in the response, meaning entries such as the network mask, default gateway, and DNS server address will not be included. Therefore, a machine that has obtained its IP address via RARP may have difficulty communicating even though it possesses this information.
To access this information, DHCP is used nowadays instead of RARP (RARP is not used at all). However, some very simple or very old devices may still be using RARP.
RARP (Reverse Address Resolution Protocol) defined in RFC 903 is used to map MAC addresses to IP addresses in a TCP/IP network.
Contrary to popular belief, RARP is not used for "pure" communication. In a RARP request, the same MAC address is typically written as both the requester and the respondent MAC address, indicating that the primary purpose of RARP is to determine the local machine's IP address.
On the other hand, only the IP address of that machine will be known in the response, meaning entries such as the network mask, default gateway, and DNS server address will not be included. Therefore, a machine that has obtained its IP address via RARP may have difficulty communicating even though it possesses this information.
To access this information, DHCP is used nowadays instead of RARP (RARP is not used at all). However, some very simple or very old devices may still be using RARP.