IEEE 802.15.4 Low rate wireless personal area networks (LR-WPANs) offer device level wireless connectivity. They bring to light a host of new applications as well as enhance existing applications. Due to their low cost, low power consumption and self-organization features, LR-WPANs are ideal for applications such as public security, battle field monitoring, inventory tracking as well as home and office automation. Nevertheless, one critical issue, security, needs to be solved before LR-WPANs are commonly accepted. Pursuing security in LR-WPANs is a challenging task. On one hand, wireless communications are inherently susceptible to interception and interference. On the other hand, most devices in LR-WPANs are resource-constrained and lack physical safeguards. DDoS attacks are a major security problem in wireless networks. DDoS is that lots of clients simultaneously send service requests to certain server on the internet thro wireless network such that this server is too busy to provide normal services for others. Attackers using legitimate packets and often changing package information, so that traditional detection methods based on feature descriptions are difficult to detect it. To date, various approaches have been proposed to detect DDoS attacks, but with limited success when they are used in the real world. This paper mainly focus on comparative analysis of DDoS attacks, detection and mitigation techniques are generally used. Beside this, we investigate about the approaches proposed that are considered efficient to survive in DDoS attacks. Finally, we conclude by highlighting the potential areas which can be targeted to optimized in minimizing the effects of DDoS attacks