CertiGuide to Security+  9  Chapter 3:  Infrastructure Security (Domain 3.0; 20%)       9  3.2  Media

3.2.1  Coax (Coaxial Cable) 1 2 3.2.3  Fiber

Security Issues with UTP/STP

With twisted pair networks, the main security concern is not so much direct tapping into existing cable, but adding devices to the network by plugging easily-available cables into unused ports on existing hubs, switches and routers. You can physically inspect the hubs, switches and routers on your network, to ensure that only the ports you expect are being used, are in use. You can also employ software-based network monitoring techniques to detect unauthorized nodes, as on coax-based network segments. Another security vulnerability of twisted pair (and coax-based) networks is that since they transmit information via electric pulses, they emit small amounts of electromagnetic radiation that could conceivably be eavesdropped on, by someone with the right equipment and sufficient interest.

Networks built with twisted pair cable tend to have greater fault tolerance than those built with coax. Because devices are physically arranged in a “star” network configuration, a problem with the connection of one device to the network, or one port on a hub, typically does not interfere with the rest of the network. As with Thinnet coax, many kinds of twisted pair cables look alike, but do not work alike. Be sure that you are not using Cat3 cabling to wire a gigabit network, or that if you use UTP on your STP-based Token Ring, you install the appropriate media filters to compensate for the extra noise on a UTP cable.

When buying twisted pair cabling, you need to take into account WHERE you are installing it. When running twisted pair cable in certain locations (such as in a suspended ceiling or within conduit), you need to use a more expensive version, called “plenum cable”, which has a different type of outer jacket to comply with building and fire codes.

3.2.1  Coax (Coaxial Cable) 1 2 3.2.3  Fiber