This document presents on the Reverse Address Resolution Protocol (RARP). It defines RARP as a protocol used to find the logical address for a machine that knows only its physical address. It describes how RARP works to dynamically map physical addresses to logical addresses, as ARP maps logical to physical addresses. The document outlines the uses of RARP and its limitations that led to its replacement by other protocols like BOOTP and DHCP.

1. Presentation Of
Networking Protocol
by : Anusua Basu.
( BCA 3rd sem. )
Midnapore College (Autonomous)

2. NETWORKING PROTOCOL
RARP
(Reverse Address Resolution Protocol)

3. Content :
 Introduction to rarp
 Logical address & physical address
 Translation
 Dynamic mapping
 Rarp operation
 Uses of rarp
 Alternative of rarp

4. Definition –
The Reverse Address Resolution Protocol
(RARP) is an obsolete computer networking
protocol used to find the logical address for a
machine that knows only its physical address.

5. Logical Address / IP Address :
 A logical address is a 32 bits address sequence of 1’s and 0’s.
 The hosts and routers are recognized at the network level by their logical
addresses.
 A logical address is an internet address.

6. Physical Address / Mac Address:
 In order to communicate or transfer the data from one computer to
another computer we need some address. Media Access Control
Address is a physical address which works at Data Link Layer.
 MAC Addresses are unique hardware number of a computer, which is
embedded into network card (known as Network Interface Card) during the
time of manufacturing. MAC Address is also known as Physical Address of a
network device.
 MAC addresses are unique 6 Byte or 48 bit hardware number.
• Example: 00-0b-75-b1-c0-8e
: : : : :
. . . . .

7. HOW TO FIND MAC ADDRESS :
Command for UNIX/Linux - ifconfig –a
ip link list
ip address show
Command for Windows OS - ipconfig /all
MacOS - TCP/IP Control Panel

8. Translation :
 We need both the physical address and the logical
address for packet delivery or efficient
communication.
 Thus, we need to be able to map a logical address to
its corresponding physical address and vice versa..
Solution:
Dynamic Mapping

9. Dynamic Mapping :
 Use a protocol to find another address
 ARP: Address Resolution Protocol
 Map a logical address to a physical address
 RARP: Reverse Address Resolution Protocol
 Map a physical address to a logical address

10. ARP VS RARP

12. USES OF RARP :
RARP is used to convert the ethernet address to an ip address.
It is available in the Lan technologies like FDDI,TOKEN RING LAN’S.

13. ALTERNATIVE OF RARP :
 The Reverse Address Resolution Protocol had few disadvantages which
eventually led to its replacement by BOOTP and DHCP. Some of the
disadvantages are:
 The RARP server must be located within the same physical
network.
 The computer sends the RARP request on very cheap layer of the network. Thus, it’s
unattainable for a router to forward the packet because the computer sends the RARP
request on very cheap layer of the network.
 The RARP cannot handle the subnetting process because no subnet masks are sent.
If the network is split into multiple subnets, a RARP server must be available with each
of them.
 It isn’t possible to configure the PC in a very modern network.
 It doesn’t fully utilize the potential of a network like Ethernet.