Extreme Networks ExtremeWare XOS Guide - Chapter 11: Forwarding Database; Overview of the FDB; FDB Contents

ExtremeWare XOS 11.3 Concepts Guide
249
11 Forwarding Database
This chapter describes the following topics:
● Overview of the FDB on page 249
● FDB Configuration Examples on page 251
● Configuring the FDB Aging Time on page 252
● Displaying FDB Entries on page 252
● MAC-Based Security on page 253
● Multicast FDB with Multiport Entry—Summit X450 Switch and BlackDiamond 8800 Chassis Only on
page 256
Overview of the FDB
NOTE
See the ExtremeWare XOS Command Reference Guide for details of the commands related to the FDB.
The switch maintains a database of all MAC addresses received on all of its ports. It uses the
information in this database to decide whether a frame should be forwarded or filtered.
This section covers the following topics:
● FDB Contents on page 249
● How FDB Entries Get Added on page 250
● FDB Entry Types on page 250
FDB Contents
Each Forwarding Database (FDB) entry consists of:
● The MAC address of the device
● An identifier for the port and VLAN on which it was received
● The age of the entry
● Flags
Frames destined for MAC addresses that are not in the FDB are flooded to all members of the VLAN.