randpkt − Random Packet Generator
randpkt [ −b <maxbytes> ] [ −c <count> ] [ −t <type> ] <filename>
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.
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.
Defines the number of packets to generate.
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
fddi Fiber Distributed Data Interface
giop General Inter−ORB Protocol
icmp Internet Control Message Protocol
ip Internet Protocol
llc Logical Link Control
m2m WiMAX M2M Encapsulation Protocol
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
udp User Datagram Protocol
usb Universal Serial Bus
usb−linux Universal Serial Bus with Linux specific header
To see a description of the randpkt options use:
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
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