IP traceback is one of the most effective techniques to defeat the denial-of-service attacks and distributed denial-of-service attacks. And based on previous research, available probabilistic packet marking (PPM) schemes have more advantages than other IP traceback techniques. But the traditional schemes have too low marking packets utilization. In this paper, a new distributed-log-based scheme (DLS), which combines PPM and logging techniques, is proposed to utilize marking packets sufficiently. And, theoretical analysis and simulation results have proven that this scheme can converge more quickly than others. Based on this scheme the origin of an attack path can be traced by only several packets. Moreover, a MACenhanced hierarchical IP traceback system (HITS) is proposed to supply a gap of end-host schemes. We believe that MAC-enhanced HITS can be deployed and managed more conveniently and securely than endhost schemes. And the traceback results educed by it are more credible and authoritative.