In one embodiment, a method includes sampling text in a received packet at a network
device and analyzing the sampled text using a sampled deterministic finite automata (DFA)
to identify matches between a set of regular expressions and the text. The sampled DFA is
created with the regular expressions sampled at a sampling rate calculated for the regular
expressions using operations including selecting a minimum sampling rate from sampling
rates computed for each of the regular expressions based on a minimum length of the text …