DES-3326S Layer 3 Fast Ethernet Switch User’s Guide

same port as where it originated. This keeps local packets from disrupting communications on other parts of the network.

For intrusion control, whenever a switch encounters a packet originating from or destined to a MAC address or an IP Address entered into the filter table, the switch will discard the packet.

Some filtering is done automatically by the switch:

Dynamic filtering – automatic learning and aging of MAC addresses and their location on the network. Filtering occurs to keep local traffic confined to its segment.

Filtering done by the Spanning Tree Protocol, which can filter packets based on topology, making sure that signal loops don’t occur.

Filtering done for VLAN integrity. Packets from a member of a VLAN (VLAN 2, for example) destined for a device on another VLAN (VLAN 3) will be filtered.

Some filtering requires the manual entry of information into a filtering table:

MAC address filtering – the manual entry of specific MAC addresses to be filtered from the network. Packets sent from one manually entered MAC address can be filtered from the network. The entry may be specified as either a source, a destination, or both.

IP address filtering – the manual entry of specific IP addresses to be filtered from the network (switch must be in IP Routing mode). Packets sent from one manually entered IP address to another can be filtered from the network. The entry may specified as either a source, a destination, or both (switch must be in IP Routing mode).

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Switch Management and Operating Concepts

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D-Link DES-3326S manual Some filtering is done automatically by the switch