In large network architectures, however, NAT is not sufficient. Hiding a company's IP address is definitely not enough. Therefore, using firewalls is important because firewalls stop or at least try to prevent any malicious threats from entering your network. Unlike the basic job of NAT, the firewall actually examines incoming traffic for possible vulnerabilities to prevent further access. A perfect example of the appropriate use of firewalls is the important role they play in VPN connections. User can send any kind of information through this secure tunnel without any worries, because this information is properly encrypted. Now, there are different types of firewalls available today which can be quite expensive, but in my opinion Cisco offers the best solutions so far. Unfortunately, firewalls are quite expensive for large organizations, as they need to protect larger resources depending on how many users will use the network (Stewart, J..