3.11. Summary
In this chapter, I covered the key elements of the network infrastructure and the various components involved in networking. Your infrastructure is the backbone and key to all the security capabilities of your network.
Your infrastructure includes the hardware and software necessary to run your network. The key elements used in security are routers and firewalls. Proper configuration is the key to providing services the way your network needs them. If your network security devices are improperly configured, you may be worse off than if you didn't have them at all. It's a dangerous situation when you think you're secure but in actuality you aren't.
Networks are becoming more complicated, and they're being linked to other networks at an accelerated speed. Several tools are available to help you both link and secure your networks:
VPNs
Tunneling protocols
Remote access
The connections you make using TCP/IP are based primarily on IP addresses. When coupled with a port, these addresses form a socket. Sockets are the primary method used to communicate with services and applications such as the Web and Telnet. Most services have standard sockets that operate by default. Sockets are changeable for special configurations and additional security. Changing default ports requires that users know which ports provide which services.
Network monitors are primarily troubleshooting tools, and they can be used to eavesdrop on networks. Intrusion detection systems take an active role and can control traffic and systems. IDSs use extensive rule-based procedures to check audit files and network traffic, and they can make decisions based upon those rules. In conjunction with a firewall, an IDS can offer high levels of security.
The communication media you use will determine the security of communication from the physical perspective. Several different types of media are available for networks, including:
Coax
UTP/STP
Fiber optic
Infrared
RF
Microwave
Each provides a unique challenge that requires attention to ensure that security requirements are met.
Removable media can be a carrier or storage vessel for viruses. Make sure it is scanned with antivirus software to verify that it remains clean. Removable media is also easily transported and can disappear. Physical security measures are important to prevent this from happening.