This figure uses a series of labeled boxes arranged in two rows to illustrate the SNMP PDU format. In the first row, we see a total of nine boxes shaded light blue. The first box is labeled "PDU type (0-3)." The next three boxes are designated "Get/set header," and are labeled (from left to right): "Request ID," "Error Status (0-5)," and "Error Index." The last five boxes are designated "Variables to get/set," and are labeled (left to right): "Name," "Value," "Name," "Value." This is followed by an ellipsis and an unlabeled box, suggesting that the chain is indefinite.

The entire bottom row of boxes, nine in total, is designated "SNMP PDU." The first box is labeled "PDU Type (4)." The next five boxes are designated "Trap header," and are labeled (from left to right): "Enterprise," "Agent Addr," "Trap Type (0-7)," "Specific code," and "Time stamp." The last three boxes are designated "Trap information," and are labeled (from left to right): "Name" and "Value." This is followed by an ellipsis and an unlabeled box, suggesting that the chain is indefinite.