Examining different types of ARP
On an IPv4 network, the most common types of ARP messages are requests and replies:
- A standard ARP request is a broadcast message that is sent out on the network requesting a resolution of an IP address to a MAC address.
- A standard ARP reply is a unicast message that is sent to the requesting host that provides the address resolution.
However, as we'll outline in this section, there are a few other types of ARP messages. We'll start with the Reverse Address Resolution Protocol (RARP), which is the reverse of ARP.
Reversing ARP
The opposite of ARP is RARP, in that with RARP, a client requests its IPv4 address from a computer network by using its MAC address.
Using an example rarp_request.cap
found at https://wiki.wireshark.org/SampleCaptures?action=AttachFile&do=view&target=rarp_request.cap, we can see the host requesting its IP address, as shown in the following screenshot: