Security of using sudo rather than su?

[Adam Funk]

On 2006-09-14, Alan McKinnon <alan at linuxholdings.co.za> wrote:

>> which raises the question, why in the world does the default
>> config that allow root logins?  (I know you're not supposed
>> to use the root account, but doesn't that just mean that the
>> password is random?)

Oops, I don't know where I heard that.

> It means that the account is not enabled and does not work. It 
> isn't random, it simply doesn't exist. Inspect the root entry 
> in /etc/shadow, it looks like this:
>
> root:!:13334:0:99999:7:::
>
> A random password would look something like this:
> root:$1$7wk8.uO1$x5WR7uXuf3NRHhm.rGPNi/:13374:0:::::

Right, thanks.

What's the practical difference in effect (I mean beyond what appears
in /etc/shadow) of passwd -d and passwd -l?  Is it just that the
effect of -l can be reversed back to the previously valid password?