[CentOS] Ignorant question on pam_shield

I've seen pam_shield recommended several times
for protecting against malicious login attempts;
but I'm not quite clear if this requires one
to be already running some pam-based software?

Also, I'm running shorewall,
and would prefer a shorewall based protection,
but the advice I read on googling for this
seemed excessively complicated.


-- 
Timothy Murphy  
e-mail: gayleard /at/ eircom.net
tel: +353-86-2336090, +353-1-2842366
s-mail: School of Mathematics, Trinity College, Dublin 2, Ireland