CLI Reference Guide-R03

Glossary
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MRD Multicast Router Discovery is a A protocol used by IGMP snooping and multicast routing
devices to discover which interfaces are attached to multicast routers. This process allows
IGMP-enabled devices to determine where to send multicast source and group
membership messages.
Multicast Switching A process whereby the switch filters incoming multicast frames for services for which no
attached host has registered, or forwards them to all ports contained within the designated
multicast VLAN group.
MVR Multicast VLAN Registration is a method of using a single network-wide multicast VLAN to
transmit common services, such as such as television channels or video-on-demand, across
a service-provider’s network. MVR simplifies the configuration of multicast services by using
a common VLAN for distribution, while still preserving security and data isolation for
subscribers residing in both the MVR VLAN and other standard or
private VLAN groups.
NTP Network Time Protocol provides the mechanisms to synchronize time across the network.
The time servers operate in a hierarchical-master-slave configuration in order to
synchronize local clocks within the subnet and to national time standards via wire or radio.
Out-of-Band
Management
Management of the network from a station not attached to the network.
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.
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.