So you’re looking at buying a firewall. If you have more than three computers in your home or business that share the same Internet connection, a hardware firewall is something you should consider. A hardware firewall is a device that sits between the Internet and your network, protecting all computers on the inside from intruders on the outside.
A home office firewall can cost around $100, a small business firewall around $1000 and a corporate firewall can cost over $10,000. Common firewall brands are Cisco, D-link, Juniper Networks, SonicWALL, NetGear and Billion.
Some factors to consider when comparing firewalls are filtering and security. Filtering is done using various techniques such as packeting filtering and stateful packet inspection (SPI). Most firewalls will allow a filter to be configured on outbound and inbound traffic. Common network protocols to filter are NetBIOS, TCP/IP, UDP/IP, FTP, Telnet, ARP/RARP and DHCP.
