Yest another application-specific firewall-like tool (ldap)

http://resources.idgenterprise.com/original/AST-0024304_Quest_WP_Its9AMKnowWhatDirectoryDoing.pdf

what is most interesting in tools like that is 

a) similar functionality is rarely integrated in firewalls, despite the fact it is most obvious place for deployment.
firewall vendors show little to no interest, though
b) tool vendors are likely to avoid the word "firewall"
c) there is zillion of it for various protocols and scenarios and no one ever thinks on making uniform solution of those
components