The Network Simulator 2 (ns-2) is largely the most used simulator in the Ad Hoc research community. However, the 802.11 DCF module implemented in the default distribution of ns-2 presents some bugs, i.e., discordances with the IEEE 802.11 Standard specifications.
We present in this Technical Report the result of an extensive analysis of both the IEEE 802.11 DCF specification and the ns-2 module. We first describe the discordances found with respect to the different DCF.s procedures. Second, we describe the different behavior corresponding to the physical layer capture model that current wireless interfaces present. Finally we provide in the Appendix all source code modified in the different ns-2.28 files. All modified source code files can be found for download at http://dsn.tm.uni-karlsruhe.de/ns-2.28-DCF-PHY-UKA.php.