7000 Series L3 Managed Switch Reference Manual for Software v2.0

PHY

The OSI Physical Layer: The physical layer provides for transmission of cells over a physical medium

connecting two ATM devices. This physical layer is comprised of two sublayers: the Physical Medium Dependent (PMD) sublayer, and the Transmission Convergence (TC) sublayer.

PIM-DM

See “Protocol Independent Multicast – Dense Mode” on page 20.

PMC

Packet Mode Channel.

Point-to-Point Protocol

PPP. A protocol allowing a computer using TCP/IP to connect directly to the Internet.

Port Mirroring

Also known as a roving analysis port. This is a method of monitoring network traffic that forwards a copy of each incoming and outgoing packet from one port of a network switch to another port where the packet can be studied. A network administrator uses port mirroring as a diagnostic tool or debugging feature, especially 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.

Glossary

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NETGEAR L3 manual See Protocol Independent Multicast Dense Mode on