Buffer overflows are among the most common security vulnerabilities in current IT systems. An attempt is made to describe how they occur, how to suppress the direct consequences and what measures can be taken to protect the overall system. This is the written summary of this lecture.

There is a variety of tools to filter packets from a network. One of the most popular ones is the Berkeley Packet Filter (BPF). All such filters are based on static descriptions, e.g., fixed source ports or fixed subnets of IP addresses. These methods work well for most types of network traffic, but there are cases in which a wider variety of applications may be appropriate. In this paper we will introduce a new analysis tool which will allow us to do a time-dependent analysis.

The libpcap is the foundation of many different tools for monitoring, diagnosing and protecting networks. A bug in the implementation of the analysis of VLANs (802.1q) leads to these programs not receiving important network traffic. This is the written summary of this lecture.