My Protocol packet map
Build the complete stack from Ethernet through your custom protocol header and payload. Byte 0 starts at the upper left; each new row continues with the next four bytes. Created by Zoxality and free to use on this website.
Total
0B
0 bitStandard
0B
L2 + L3 + L4Custom header
0B
non-payloadPayload
0B
payloadRows
0
4 byte / radMTU remaining
0B
budget 1500 BBit / byte layout
Double-click directly in the packet map. A free bit opens the bit editor; a bit inside a byte-owned field opens the complete byte.
Double-click to edit bits / bytes
Ethernet
IP
Transport
Custom
Payload
Crypto
About this tool
Zoxality Protocol Forge was created by Zoxality as a practical visual tool for designing, documenting, testing and discussing packet and protocol formats.
Zoxality Protocol Forge is free to use on this website for protocol design, engineering, documentation, education, research and prototyping.
The Protocol Forge software, source code, interface and underlying implementation are the property of Zoxality and are not provided for redistribution, copying, modification or independent hosting unless expressly authorised by Zoxality.
Projects created with Protocol Forge can be exported and imported as JSON, and generated packet layouts, state machines and specifications can be saved or printed for use in your own projects.
Technical note
Ethernet II
Destination MAC 48 bits + Source MAC 48 bits + EtherType 16 bits = 14 bytes. 802.1Q is inserted before EtherType.
IP
The IPv4 template is the 20-byte minimum header without options. The IPv6 base header is 40 bytes without extension headers.
Transport
UDP is 8 bytes. TCP is shown as the 20-byte minimum header without options.
MTU
The MTU value is a design budget. It does not automatically modify Ethernet/IP fields; it shows how much space remains.