Securing Your Network

A secure Web application relies upon a secure network infrastructure. The network infrastructure consists of routers, firewalls, and switches. The role of the secure network is not only to protect itself from TCP/IP-based attacks, but also to implement countermeasures such as secure administrative interfaces and strong passwords. The secure network is also responsible for ensuring the integrity of the traffic that it is forwarding. If you know at the network layer about ports, protocols, or communication that may be harmful , counter those potential threats at that layer.

Network Component Categories

This guide divides network security into separate component categories as shown in Table 1.1.

Table 1.1: Network Component Categories

Component	Description
Router	Routers are your outermost network ring. They channel packets to ports and protocols that your application needs. Common TCP/IP vulnerabilities are blocked at this ring.
Firewall	The firewall blocks those protocols and ports that the application does not use. Additionally, firewalls enforce secure network traffic by providing application-specific filtering to block malicious communications.
Switch	Switches are used to separate network segments. They are frequently overlooked or overtrusted.