[lemma=perimeter] □ □
[lemma=perimeter] □ □ □
[lemma=perimeter] □* □
Most integrated appliances include technology for firewalls , which harden the perimeter of a network by blocking traffic that fails to meet certain requirements ; virtual private networks ( VPNs ) , private networks that use encryption to transmit data within public networks ; and some form of intrusion prevention technology , which prevents network attacks by intercepting and forwarding packets of data in real time . Repair bracket scaffold means a supported scaffold consisting of a platform supported by brackets which are secured in place around the circumference or perimeter of a chimney , stack , tank or other supporting structure by one or more wire ropes placed around the supporting structure .