Broadcasting and unicasting of packets in different protocols

[Dimensioner]

I am a networking student , I had a bit of doubt regarding the protocol being used in the networking, I was more concerned about the packets being broadcasted and unicasted in certain protocols such as ARP and the RARP , what exactly you mean when you say that the packet is being broadcasted and unicasted, I will also appreciate if you can explain a bit about the working of this protocol , I am waiting for your response , I hope I will get plenty of responses so that I can clear out my doubt. Thank you in advance .

[Wguy2008]

ARP replies are absolutely unicast -- RFC 826 states that replies must be sent to "the (new) target Machine address on the similar hardware on which the request was received." the majority RARP implementations would most likely do the same thing because they are same -looking and similarly -named protocols. But you can not totally rely on it , I hope from my post and above given posts you would have been content.

[Pabloa]

I would presume that most real-world implementations would make use of unicast, just because that is what ARP does. You can search around over net and look into various networking books , you will find that they all explain the RARP replies as being unicast .If you are really interested, establish a small RARP environment and a protocol analyzer like Ethereal or tcpdump and see what you receive when you put them on the cable.

[Paisley007]

Address Resolution Protocol (ARP) floats in the shadows of most networks. Because of its straightforwardness, in contrast to higher layer protocols, ARP hardly ever break in upon the network administrator's routine.Every modern IP-capable operating systems offer support for ARP. The unusual substitute to ARP is static link-layer-to-IP mappings. That was just an overview of the protocol you were talking about , as far as your question is concerned , the packets are really broadcasted in this protocol, the actual receptor accepts the requests , and rest all of them rejects it. And in case of RARP it is quite opposite process , there the replies are being unicasted that is the reply is sent to the destined or dedicated machine address only once the mapping is done.

[addie]

ARP describes the exchanges among network interfaces connected to an Ethernet media section in order to map an IP address to a link layer address on request. Link layer addresses are hardware addresses (although they are not immutable) on Ethernet cards and IP addresses are logical addresses allocated to machines connected to the Ethernet. afterward in this chapter, link layer addresses may be recognized by many diverse names: Ethernet addresses, Media Access Control (MAC) addresses, and the hardware addresses. Disputably, the accurate word from the kernel's viewpoint is "link layer address" since this address can be altered (on many Ethernet cards) by means of command line tools. Nonetheless, these terms are not sensibly distinct and can be used interchangeably.