These appendixes provide a number of useful checklists and referances.

• Appendix A, UNIX Security Checklist , contains a point-by-point list of many of the suggestions made in the text of the book.

• Appendix B, Important Files , is a list of the important files in the UNIX filesystem, and a brief discussion of their security implications.

• Appendix C, UNIX Processes , is a technical discussion of how the UNIX system manages processes. It also describes some of the special attributes of processes, including the UID, GID, and SUID.

• Appendix D, Paper Sources , list books, article, and magazines about computer security.

• Appendix E, Electronic Resources , is a brif listing of some significant security tools to use with UNIX, including directions on where to find them on the Internet.

• Appendix F, Organizations , contains the names, telephone numbers, and addresses of organizations that are devoted to seeing computers become more secure.

• Appendix G, Table of IP Services , lists the common TCP/IP protocols, along with their port numbers and suggested handling by a firewall.