Detection of Trial and Error Traffic Engineering with BGP-4

BGP-4 is the routing protocol which holds the Internet together. Additionally and in the absence of a better solution, it is being used for traffic engineering purposes. In the absence of standardised procedures, each autonomous system in the Internet implements traffic engineering based on non-collaborative goals and using trial and error techniques. This paper analyses trial and error traffic engineering. BGP-4 update sequences which flag the use of trial and error traffic engineering techniques are presented, along with an algorithm to detect them. A trial and error traffic engineering abnormality is presented. It was detected when analysing the RIPE routing repositories using the detection algorithm.