Problem:

a) Give and Illustrate with the help of diagrams, four topologies for the Network Information System (NIS).

b) Give methods for creating user accounts and groups.

c) Write the Linux command to provide full permissions to the user, group and anyone of the file named admin002 using chmod with 3 octal digits.

d) Explain the command chmod a+x admin001.

e) Give the umask value for files so that they are given the permissions rw-r--r--

f) Define a rule that will silently block incoming SMTP connections from spmr.com.