Firewalls By conventional definition, a firewall is a partition made of fireproof material designed to prevent the spread of fire from one part of a building to another. firewall isolates organization's internal net from larger Internet, allowing some packets to pass, blocking others privately administered Internet 222.22/16Firewalls 4 isolates organization’s internal net from larger Internet, allowing some packets to pass, blocking others. firewall privately administered Internet 222.22/16 By conventional definition, a firewall is a partition made of fireproof material designed to prevent the spread of fire from one part of a building to another