Firewallsaredevicesorprogramsthatcontroltheflowofnetworktrafficbetweennetworksorhostsemployingdifferingsecuritypostures.Thispublicationprovidesanoverviewofseveraltypesoffirewalltechnologiesanddiscussestheirsecuritycapabilitiesandtheirrelativeadvantagesanddisadvantagesindetail.Italsomakes