#readwise # Network Foundations - Components of a Network  ## Metadata - Author: [[Hack The Box]] - Full Title: Network Foundations - Components of a Network - URL: https://academy.hackthebox.com/module/289/section/3237 ## Summary A network consists of various components that help devices communicate and share resources. End devices, like computers and smartphones, allow users to interact with the network. Intermediary devices, such as routers and switches, manage data traffic and ensure secure connections. Servers provide services and resources, enabling efficient data access and management. ## Highlights A `router` is an intermediary device that plays a hugely important role - the forwarding of data packets between networks, and ultimately directing internet traffic. Operating at the network layer (Layer 3) of the OSI model, routers read the network address information in data packets to determine their destinations. They use routing tables and routing protocols—such as `Open Shortest Path First (OSPF)` or `Border Gateway Protocol (BGP)`—to find the most efficient path for data to travel across interconnected networks, including the internet. They fulfill this role by `examining incoming data packets` and forwarding them toward their destinations, based on IP addresses. By `connecting multiple networks`, routers enable devices on different networks to communicate. They also manage network traffic by selecting optimal paths for data transmission, which helps prevent congestion—a process known as `traffic management`. Additionally, routers enhance `security` by incorporating features like firewalls and access control lists, protecting the network from unauthorized access and potential threats. ([View Highlight](https://read.readwise.io/read/01jnx05mb3wyz4yzsbb4brx9jx)) ^gzvl7j --- A `software firewall` is a security application installed on individual computers or devices that monitors and controls incoming and outgoing network traffic based on predetermined security rules. Unlike hardware firewalls that protect entire networks, software firewalls (also called Host-based firewalls) provide protection at the device level, guarding against threats that may bypass the network perimeter defenses. They help prevent unauthorized access, reject incoming packets that contain suspicious or malicious data, and can be configured to restrict access to certain applications or services. For example, most operating systems include a built-in software firewall that can be set up to block incoming connections from untrusted sources, ensuring that only legitimate network traffic reaches the device. ([View Highlight](https://read.readwise.io/read/01jnx0ct79ddk6f5xxyd59y0c7)) ^uxz1e2 ---