How to Protect Your Network With a Firewall
A firewall is a hardware or software system that filters data traffic and allows or blocks access based on predetermined rules. It serves as a barrier between your internal network devices and external sources such as the internet. The firewall vetting process is like the bouncer checking IDs at your network door: it keeps unauthorized connections out and lets legitimate ones in.
Firewalls are one of the cybersecurity industry’s fundamental staples, but they must constantly adapt to evolving cyber threats. By selecting the right firewall, configuring it properly and staying on top of maintenance tasks like monitoring firewall logs, businesses can reduce their risk.
Packet filtering firewalls (also known as stateless inspection firewalls) operate at the OSI network layer and analyze individual data packets based on IP addresses, port numbers and protocol. These first-generation firewall technologies don’t retain information about previous connection histories, so every packet must be evaluated as if it were the first time it was being sent.
Stateful inspection firewalls are designed to learn and make decisions based on previously approved connections. The firewall builds a state table that tracks open connections, and then examines each new packet to determine if it matches an existing entry. This gives the firewall context in its decision making and helps protect networks from attacks that target established connections, such as denial of service (DoS) attacks.
Next-generation firewalls, also known as NGFWs, combine a number of key assets to create an advanced security mechanism that’s well-rounded against today’s threats. These include: