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Annotated edit history of ARP version 3, including all changes. View license author blame.
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3 AristotlePagaltzis 1 An [Acronym] for __A__ddress __R__esolution __P__rotocol.
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3 AristotlePagaltzis 3 A protocol that enables a [IP] conversation to occur over an [Ethernet] network. [IP] (version 4) uses 32-bit addresses, usually displayed in a dotted quad format, <tt>nnn.nnn.nnn.nnn</tt>. [Ethernet] uses 48-bit addresses, known as [MAC] addresses, usually displayed as a 17-character colon-delimited hex string, <tt>nn:nn:nn:nn:nn:nn</tt>. (A real example: my workstation has the IP address <tt>192.168.1.46</tt> and a MAC address of <tt>00:50:FC:B1:21:C7</tt>)
1 JimCheetham 4
3 AristotlePagaltzis 5 In order to send an [IP] packet over [Ethernet], your computer needs to associate a [MAC] address with the requested [IP] address. It does this by sending an [Ethernet] Broadcast packet, using the [ARP] protocol. This packet basically says "What [MAC] address is associated with this [IP] address?", sometimes referred to as a "who-has?" request.
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3 AristotlePagaltzis 7 Although any workstation on the local [Ethernet] is capable of sending a response, usually it is only the actual workstation you wish to communicate with that bothers to reply, providing both its [IP] address and its [MAC] address.
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3 AristotlePagaltzis 9 To issue a gratuatis [ARP] to flush an [ARP] cache use arping(8).
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3 AristotlePagaltzis 11 ----
12 CategoryProtocols