5 reasons TAPs are better than SPAN ports.
If the speed of the SPAN port becomes overloaded frames are dropped. Because the SPAN session copies full-duplex traffic, a fully loaded 1Gbps link actually can produce 2Gbps of traffic to the monitor port oversubscribing the capability of the port. Note also, that SPAN traffic is the lowest priority traffic in the switch. This will cause all output traffic beyond 1Gbps to be dropped.
Proper spanning requires that a network engineer configure the switches properly and this takes away from the more important tasks that network engineers have many times configurations can become a political issue (constantly creating contention between the IT team, the security team, and the compliance team). The TAP, on the other hand, is independent of the network endpoints making up a link. There are many different points in the network where taps can be inserted offering access to a variety of analysis, compliance, and security tools.
Because of a TAP’s independence from the network endpoints, it can copy 100% of the data to the monitor port. Physical layer errors, error packets, short frames, and other packets that might be filtered out on a SPAN session are all passed through TAPs to the monitor port(s). This provides the IT Manager with a legally defensible, pure data stream for analysis and reporting. TAPs guarantee access to all the data all the time.
TAPs do not analyze packets, change packet timing, alter or otherwise interfere with network traffic. While Spanning or mirroring changes the timing of the frame interaction (what you see is not what really happened).
TAPs also provide flexibility in how they pass traffic to the monitor port. There are four different modes of operation: Breakout, Aggregation, Regeneration, and Inline or Bypass TAP. Allowing for out-of-band and in-line operations.
In summary, IT Managers are increasingly turning to TAPs as the preferred method for connecting network, performance, and security tools. TAPs provide access to all the data to ensure an accurate analysis. They grant fail-safe operation avoiding the risk of network disruption as a result of power interruption or failure of an appliance.
To learn more about network TAPs and the key features to optimize your network traffic visibility, visit https://www.networkcritical.com/network-taps and become an expert on your network!