The Assimilation Project  based on Assimilation version 1.1.7.1474836767
Layout of ARP Packets

ARP is the Address Resolution Protocol - which we receive and then map IP to MAC addresses. More...

Collaboration diagram for Layout of ARP Packets:

Modules

 ARP: Offsets of initial items in an ARP packet.
 The initial items are the hardware and protocol types, address lengths, and the operation code.
 

Detailed Description

ARP is the Address Resolution Protocol - which we receive and then map IP to MAC addresses.

ARP packets consist of a 8-byte initial header, followed by sender and target Hardware and IP Addresses. An ARP packet should never exceed ??? bytes. The ARP Packet (after ethernet and SNAP headers) is laid out as shown below:

+-------------------------------—+-------------------------------—+
|        Hardware Type (HRD)       |        Protocol Type (PRO)       |
|              2 bytes             |              2 bytes             |
|--------------—+-------------—+-------------------------------—|
|  Hardware       |  Protocol      |                                  |
|  Address        |  Address       |            Opcode (OP)           |
|  Length (HLN)   |  Length (PLN)  |              2 bytes             |
|     1 byte      |     1 byte     |                                  |
|--------------—+-------------—+-------------------------------—|
|                     Sender Hardware Address (SHA)                   |
|                              HLN bytes                              |
|                                  +-------------------------------—|
|                                  |   Sender Protocol Address (SPA)  |
|                                  |        4 bytes (bytes 1-2)       |
|-------------------------------—+-------------------------------—|
|      Sender Protocol Address     |                                  |
|            (bytes 3-4)           |                                  |
|-------------------------------—+                                  |
|                                      Target Hardware Address (THA)  |
HLN bytes
Target Protocol Address (TPA)
4 bytes
+------------------------------------------------------------------—+