QUOTE]im not looking to spoof my MAC im wan tto spoof an arp reply[/QUOTE]

Well now that’s an interesting response. Since an ARP Request attempts to find the data link layer (MAC) address of a given IP Address.

So I gotta ask you if you really know what you will be doing if you do spoof an ARP Response? I’ll let you know anyway. You will cause all other units on that network to update their ARP tables with the false mapping you created. Once these other tables contain the fictitious info, packets will be sent to the spoofed address. These packets could contain all kinds of sensitive information. FYI this is called the “Man in the Middle Attack” and a variant of the same is ARP Poisoning (both of which could introduce you to a cellmate called BuBBa).

Won't help you there. But now if it is for testing on your own network, you should learn the whole thing instead of just having someone give you a packet builder or some other software. You should study and understand the elements/format of an ARP/RARP Request and Response. Below are some sites to get you started with a basic understanding of ARP and also you should study the TCP/IP Protocol Stack. So good luck.

http://www.erg.abdn.ac.uk/users/gorr...pages/arp.html

http://www.geocities.com/SiliconVall...twork/arp.html