NETGEAR ProSafe GSM7224 User Manual page 222

User Manual for the NETGEAR 7200 Series Layer 2 Managed Switch Software
when fending off an attack. It enables the administrator to keep close track of switch performance and alter it
if necessary. Port mirroring can be managed locally or remotely. An administrator configures port mirroring
by assigning a port from which to copy all packets and another port where those packets will be sent. A
packet bound for or heading away from the first port will be forwarded onto the second port as well. The
administrator places a protocol analyzer on the port receiving the mirrored data to monitor each segment
separately. The analyzer captures and evaluates the data without affecting the client on the original port. The
monitor port may be a port on the same SwitchModule with an attached RMON probe, a port on a different
SwitchModule in the same hub, or the SwitchModule processor. Port mirroring can consume significant
CPU resources while active. Better choices for long-term monitoring may include a passive tap like an
optical probe or an Ethernet repeater.
Port monitoring
The ability to monitor the traffic passing through a port on a device to analyze network characteristics and
perform troubleshooting.
Port speed
The speed that a port on a device uses to communicate with another device or the network.
Port trunking
The ability to combine multiple ports on a device to create a single, high-bandwidth connection.
Protocol
A set of rules for communication between devices on a network.
Protocol Data Unit
PDU is a packet of data passed across a network. The term implies a specific layer of the OSI model and a
specific protocol.
Q
QoS
See "Quality of Service" on page 14.
Quality of Service
QoS is a networking term that specifies a guaranteed level of throughput. Throughput is the amount of data
transferred from one device to another or processed in a specified amount of time - typically, throughputs are
measured in bytes per second (Bps).
C-14 Glossary
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