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AxioTAP™ is the perfect solution for Switched Networks
The most commonly used method to implement monitoring devices into a switched network is port spanning, also known as port mirroring. This option has inherent flaws that create device implementation problems. Most switches in use today come with this type of port. Port spanning or mirroring forces the switch to either send all packets from across the switch, or packets from a specified port, to a specific span/monitoring port in addition to delivering it to its intended recipient. This raises an issue of packet loss to the mirror/span port. When utilizing such a port, it is much like a port on a hub. This means that there will be a higher rate of packet collisions, as the other ports on the switch continually send packets to the mirror/span port. Switches also are constrained by the bandwidth capacity of the SPAN port, since this port usually has the same amount of bandwidth as every other single port has; the packet loss is significantly increased.
Port mirroring also presents additional problems in that it does not receive error packets or VLAN information, and only presents one side of a full-duplex connection. Thus, the detection device sitting on a mirror port is severely limited by increased packet loss, and a complete blindness to half of the traffic on a link. Corrupt network packets, or packets below minimum size, are usually dropped.
Span Port Issues:
- Packet Loss
- Switch routing, low priority
- Duplex monitoring unlikely
- Physical Layers 1 and 2 not monitored
- Port is usually oversubscribed
- Limited Stealth from Detection
- Potential Point of Failure
For switched network environments that demand full-duplex gigabit monitoring SPAN ports or mirror ports are inadequate. The AxioTAP enables complete visibility to full-duplex links without frame arrival time distortion or packets drop. Plus AxioTAPs do not affect switch performance and assure maximum data delivery to the monitoring devices.
