# NAME

randpkt - Random packet generator

# SYNOPSIS

randpkt [ -b <maxbytes> ] [ -c <count> ] [ -t <type> ] <filename>

# DESCRIPTION

randpkt is a small utility that creates a pcap trace file full of random packets.

By creating many randomized packets of a certain type, you can test packet sniffers to see how well they handle malformed packets. The sniffer can never trust the data that it sees in the packet because you can always sniff a very bad packet that conforms to no standard. randpkt produces very bad packets.

When creating packets of a certain type, randpkt uses a sample packet that is stored internally to randpkt. It uses this as the starting point for your random packets, and then adds extra random bytes to the end of this sample packet.

For example, if you choose to create random ARP packets, randpkt will create a packet which contains a predetermined Ethernet II header, with the Type field set to ARP. After the Ethernet II header, it will put a random number of bytes with random values.

# OPTIONS

-b <maxbytes>

  Default 5000.

  Defines the maximum number of bytes added to the sample packet. If you choose a maxbytes value that is less than the size of the sample packet, then your packets would contain only the sample packet... not much variance there! randpkt exits on that condition.

-c <count>

  Default 1000.

  Defines the number of packets to generate.

-t <type>

  Default Ethernet II frame.

  Defines the type of packet to generate:

              arp             Address Resolution Protocol
              bgp             Border Gateway Protocol
              bvlc            BACnet Virtual Link Control
              dns             Domain Name Service
              eth             Ethernet
              fddi            Fiber Distributed Data Interface
              giop            General Inter-ORB Protocol
              icmp            Internet Control Message Protocol
              ip              Internet Protocol
              ipv6            Internet Protocol Version 6
              llc             Logical Link Control
              m2m             WiMAX M2M Encapsulation Protocol
              megaco          MEGACO
              nbns            NetBIOS-over-TCP Name Service
              ncp2222         NetWare Core Protocol
              sctp            Stream Control Transmission Protocol
              syslog          Syslog message
              tds             TDS NetLib
              tcp             Transmission Control Protocol
              tr              Token-Ring
              udp             User Datagram Protocol
              usb             Universal Serial Bus
              usb-linux       Universal Serial Bus with Linux specific header

# EXAMPLES

To see a description of the randpkt options use:

        randpkt

To generate a capture file with 1000 DNS packets use:

        randpkt -b 500 -t dns rand_dns.pcap

To generate a small capture file with just a single LLC frame use:

        randpkt -b 100 -c 1 -t llc single_llc.pcap

# SEE ALSO

pcap(3), editcap(1)