Was wondering a few things about the unix box in college.

I was having a look around the unix box in my college tonight and i noticed a few things that i have a few questions about.

The root account cannot be logged into except from the terminal that is hooked up to the server. When i enter the username and password it outputs a message saying This account cannot be logged into except from the console. How is this implemented.

I was also looking at how often the root account is accessed using the following command "last | grep root | more".
From the output i recieved i saw that everytime the root account is accessed there are two login entries. ie

somenumbers root console time date
somenumbers root 0: time date

The time and date are exactly the same. Why is there two login entries for every login?

This might not be the correct forum i dunno where else to put it.

 

The terminal only allowing root to logon on the console is a security feature. If you need to do root tasks from afar you can logon as a normal user and use the su command to become root.