Quantifying the Accuracy of Small Subnet-Equivalent Sampling of IPv4 Internet Background Radiation Datasets

Network telescopes have been used for over a decade to aid in identifying threats by gathering unsolicited network traffic. This Internet Background Radiation (IBR) data has proved to be a significant source of intelligence in combating emerging threats on the Internet at large. Traditionally, operation has required a significant contiguous block of IP addresses. Continued operation of such sensors by researchers and adoption by organisations as part of its operation intelligence is becoming a challenge due to the global shortage of IPv4 addresses. The pressure is on to use allocated IP addresses for operational purposes. Future use of IBR collection methods is likely to be limited to smaller IP address pools, which may not be contiguous. This paper offers a first step towards evaluating the feasibility of such small sensors. An evaluation is conducted of the random sampling of various subnet sized equivalents. The accuracy of observable data is compared against a traditional 'small' IPv4 network telescope using a /24 net-block. Results show that for much of the IBR data, sensors consisting of smaller, non-contiguous blocks of addresses are able to achieve high accuracy rates vs. the base case. While the results obtained given the current nature of IBR, it proves the viability for organisations to utilise free IP addresses within their networks for IBR collection and ultimately the production of Threat intelligence.