Chapter 3: Transport Layer Attacks and Defense
The transport layer is the realm of server reconnaissance with port scans and sweeps, and this chapter examines the inner workings of these methods. The iptables logging format is well suited to representing transport layer header information, and this is useful for detecting all sorts of mischief.The figures below represent the completeness of the iptables logging format for TCP and UDP headers, and are discussed in Chapter 3.
iptables LOG Coverage of the TCP Header:
iptables LOG Coverage of the UDP Header: