Random TCP Offset

This is not really an errata, but we forgot to say something important about random offsets for the sequence numbers and acknowledgement number. On page 92 the text describes these as starting from 0 or 1 and then increasing. However, to defeat certain types of packet injection attacks, a random offset is chosen for the initial packet. The log from Wireshark thus uses large numbers; but these are not because a large amount of data has been sent.