While testing a system, nmap told me that the tcp seq number prediction is really low, (trivial joke). There is only one system in the whole range that gives me that answer. Some papers, e.g. a weakness in the 4.2 bsd unix tcp/ip software, that even though it's old, describes the problem, seem to point that today seq numbers are generated more securely.
I wondered, is there any other tool then nmap with which I could verify the tcp seq number prediction? It'd give me more confidence in the result.