Definition - What does Network Tap mean?
A network tap is a test access point or hardware device placed at a specific network point where data can be accessed. The aim of a network tap is for a third party to monitor the network traffic between two terminals.
Network taps are usually employed for network intrusion detection systems (NIDS), network probes, remote network monitoring (RMON) probes and Voice Over Internet Protocol (VoIP) recording.
Techopedia explains Network Tap
Network taps are placed between two points of a network to monitor its segments. A pair of cables replaces the network cable between two points. Later on, the pair of cables is attached to the network tap device. Network traffic flows through the tap device without any interruption. The network tap device sends a copy of the traffic to the monitoring port without notifying the network.
Network taps are unobtrusive and undetectable. They are therefore widely used in network security applications. Network taps work with full duplex communication systems and let the traffic flow smoothly, even with traffic failure.
Network taps are categorized into four basic types:
- Breakout Taps: The simplest form of network taps, breakout taps usually consist of two input and two output ports.
- Aggregating Taps: These taps collect the network traffic information from multiple segments and combine it into a single monitoring port using a single monitoring tool.
- Regeneration Taps: These taps collect traffic information only once from one segment and send it to different monitoring devices to analyze the data.
- V-Line Taps: These allow the tap to connect a virtual inline network device.
One advantage of network taps is their use to monitor traffic without any interference. However, there are also disadvantages. They are expensive to employ because they need additional hardware. Monitoring a large network via network taps requires various monitoring devices. And, placing a network tap for a short time can also interrupt network traffic, while fully passive network taps can even cause a failure in the network by introducing new points of failure.