GarrettCom 4K-Series manual Switching Functionality, Filtering and Forwarding, Address Learning

Magnum 4K8 Switches Installation and User Guide (10/04)

4.0OPERATION

This chapter describes the functions and operation of the 4K8 Switch.

4.1Switching Functionality

AMagnum 4K-Series provides switched connectivity at Ethernet wire-speed among all of its ports. The Magnum 4K-Series supports10/100Mbs for copper media and 10 or 100Mb separate traffic domain for fiber port to maximize bandwidth utilization and network performance. All ports can communicate to all other ports in a Magnum 4K8, but local traffic on a port will not consume any of the bandwidth on any other port.

Magnum 4K-Series units are plug-and-play devices. There is no software configuring to be done at installation or for maintenance. The only hardware configuration settings are user options for bonus port (port# 9) on RJ-45 and fiber port. Half / Full duplex mode and 10 or 100Mbps selection for the switched ports can be done through jumper settings inside the unit. The internal functions of both are described below.

Filtering and Forwarding

Each time a packet arrives on one of the switched ports, the decision is taken to either filter or to forward the packet. Packets whose source and destination addresses are on the same port segment will be filtered, constraining them to that one port and relieving the rest of the network from processing them. A packet whose destination address is on another port segment will be forwarded to the appropriate port, and will not be sent to the other ports where it is not needed. Traffic needed for maintaining the operation of the network (such as occasional multi-cast packets) is forwarded to all ports.

The Magnum 4K-Series Switches operate in the store-and-forward switching mode, which eliminates bad packets and enables peak performance to be achieved when there is heavy traffic on the network.

Address Learning

All 8-port Magnum 4K-Series units have address table capacity of 16K node addresses suitable for use in large networks. They are self-learning, so that as nodes are added or removed or moved from one segment to another, the 4K8-Port Switch automatically keeps up with node locations.

An address-aging algorithm causes least-used addresses to fall out in favor of

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