Purpose of the Packet Generator Tool

The purpose of this tool is to create a TCP, UDP, ICMP, ARP, CDP or RAW format packet or set of packets to send to a target, then observe the target's response with a packet capturing tool like Packet Capture or Wireshark. The tool can also playback previously captured packet files. This tool can also be used to help determine where specific packet types are being lost between machines.

A Packet Generating and Crafting Tool

The NetScanTools Pro Packet Generator tool allows you to craft or build a TCP, UDP, ICMP, CDP (Cisco® Discovery Protocol), ARP/RARP or RAW packet and send one or more packets to a target IPv4 address.


You have full control over the headers: ethernet source and destination MAC addresses, IP, TCP, UDP or ICMP header fields. You can send different types of packets in succession using scripting. You can also play back a previously saved packet capture file.


Related Tool Links

Packet Generator

Packet Generator Screenshot

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Important Notes about the Packet Generator
  • This tool uses WinPcap to send packets. The network interface you use to send packets must be compatible with WinPcap. Best results are usually obtained from a wired ethernet interface or a 802.11 wireless interface.
  • This tool does not send packets at a rate necessary to stress or otherwise saturate an interface. It is not a high speed Traffic Generator and it does not respond to packets coming back. Please consider the Packet Flooder Tool.

Packet Generator Tool Capabilities


  • Sends TCP, UDP, ICMP, CDP, ARP/RARP or RAW Packets to the IPv4 address specified.
  • Full header control for predefined packet types. You can specify most parameters in the header such as source and destination IPv4 address, packet length, packet types, flags and checksums. The ethernet source and destination address can also be defined.
  • Data Payloads can be added for certain types of packets. The payload can be simple text or a file of your choosing. The length of the data payload is limited by the interface MTU and the packet type. We provide a Hex Editor to assist in creating or editing binary packet payloads or creating RAW packets.
  • RAW Packet mode gives you full control. RAW packet mode simply means that you define the packet from ethernet header to the end using our Hex Editor or another editor. Then you send the packet. The length of the raw packet is limited by the interface MTU.
  • Playback previously saved .pcap files at the rate they were captured or as fast as possible.
  • The packet size is limited to the MTU of your network, typically 1460 bytes for ethernet.
  • Scripting. Simple scripting is provided so that you can send different types packets. Scripted packet transmission can be used to send packets with parameters changing according to your script.
  • Virtual machine ethernet interfaces. This tool works best with physical ethernet interfaces and we do use it with Oracle VirtualBox VMs. Just be sure to set the VM network interface to bridged mode so that it goes directly to your host physical ethernet interface without going through the VM NAT interface.

What this tool does not do

  • This tool is NOT a traffic generator or packet flooding tool capable of stressing a network interface - if you need to send lots of UDP packets, use our Packet Flooder tool. Burst rate of the Packet Generator tool is about 20Khz and this may vary from computer to computer.
  • This is not a bandwidth testing tool. You are looking for dedicated hardware: Agilent Technologies and Fluke both make these type of devices.
  • This tool does not support handshaking of TCP connections - in other words, it does not listen for a response during a TCP handshake and send a different TCP packet in reply. So if you send a SYN and a SYN/ACK comes back, this tool does not continue to build up the TCP connection.
  • This tool may or may not operate properly from within a virtual machine ethernet interface. This tool works best with physical ethernet interfaces. You are welcome to try it with your virtual machine, but do not count on it working perfectly - be sure to set it into 'bridged' mode
  • This tool does not have the ability to send custom packets through WAN (PPP/SLIP) interfaces like modems or wireless cellular modems. This tool is limited to sending through wired ethernet or wireless 802.11x interfaces.

Types of Packets Generated

These pages explore the modes of Packet Generation:

RAW packet sends are the most versatile. You specifiy the whole packet from ethernet headers to the end and send it. Any protocol that works with ethernet can be sent.

Packet Player

Packet Generator Packet Player Screenshot

HEX File Editor

HEX File Editor Screenshot

TCP Send Mode

Packet Generator TCP Packet Definition Screenshot

UDP Send Mode

Packet Generator UDP Packet Definition Screenshot

ICMPv4 Send Mode

Packet Generator ICMPv4 Packet Definition Screenshot

CDP Mode

Packet Generator CDP Packet Definition Screenshot

ARP/RARP Mode

Packet Generator ARP/RARP Packet Definition Screenshot

RAW Packet Mode

Packet Generator RAW Packet Definition Screenshot

A video of the Packet Generator tool sending an RARP Reply Packet

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This tool uses WinPcap to send specialized packets.