CLI Reference Guide-R05

Glossary
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Port Authentication See IEEE 802.1X.
Port Mirroring A method whereby data on a target port is mirrored to a monitor port for troubleshooting
with a logic analyzer or RMON probe. This allows data on the target port to be studied
unobstructively.
Port Trunk Defines a network link aggregation and trunking method which specifies how to create a
single high-speed logical link that combines several lower-speed physical links.
Private VLANs Private VLANs provide port-based security and isolation between ports within the assigned
VLAN. Data traffic on downlink ports can only be forwarded to, and from, uplink ports.
QinQ QinQ tunneling is designed for service providers carrying traffic for multiple customers
across their networks. It is used to maintain customer-specific VLAN and Layer 2 protocol
configurations even when different customers use the same internal VLAN IDs.
QoS Quality of Service. QoS refers to the capability of a network to provide better service to
selected traffic flows using features such as data prioritization, queuing, congestion
avoidance and traffic shaping. These features effectively provide preferential treatment to
specific flows either by raising the priority of one flow or limiting the priority of another
flow.
RADIUS Remote Authentication Dial-in User Service. RADIUS is a logon authentication protocol that
uses software running on a central server to control access to RADIUS-compliant devices on
the network.
RMON Remote Monitoring. RMON provides comprehensive network monitoring capabilities. It
eliminates the polling required in standard SNMP, and can set alarms on a variety of traffic
conditions, including specific error types.
RSTP Rapid Spanning Tree Protocol. RSTP reduces the convergence time for network topology
changes to about 10% of that required by the older IEEE 802.1D STP standard.
SMTP Simple Mail Transfer Protocol is a standard host-to-host mail transport protocol that
operates over TCP, port 25.
SNMP Simple Network Management Protocol. The application protocol in the Internet suite of
protocols which offers network management services.