Chapter 9 - Managing The Address Forwarding Table; Overview - Avaya P580 User Manual

9

Overview

User Guide for the Avaya P580 and P882 Multiservice Switches, v6.0
Managing the Address
Forwarding Table
The Address Forwarding Table (AFT) is a mapping table of MAC addresses
with their associated port locations.The AFT is used by the Avaya
Multiservice switch to correctly forward (bridge) frames destined for a
particular MAC address to the correct physical port. The AFT performs
several major functions, learning new MAC addresses, aging out old MAC
addresses, and providing a management interface to display, add, modify,
and remove AFT entries (MAC addresses). AFT's are maintained
throughout the system, on media modules and the supervisor module.
There is one AFT created for each VLAN. The entire Avaya Multiservice
Switch can store up to 24,000 MAC addresses and 1000 VLANs.
* Note: Although the Avaya Multiservice Switch can support 1000
VLANs, (in Fabric mode 2 with all 80-series modules),
restrictions apply for the size of the Hash tables, the size of the
Address Forwarding Tables and the number of VLANs. This
information is detailed in the following pages in this chapter.
New address Learning - When a MAC address of a packet is
unknown, it must be learned by the AFT
Address Aging - On a periodic basis (which you can set) the
addresses in the AFT are aged out, MAC addresses not received for
a period of time (e.g. 5 minutes) are removed from the AFT along
with their port associations.
Static Address Management - Static MAC address entries are saved
in memory upon module reset. These static address always exists in
the AFT, and are not aged out or overwritten.Static entries are those
manually configured. Each VLAN and its AFT has 18 AFT entries
automatically entered by the switch that are reserved for internal
use.
Address Management - The user has the ability to display entries,
add entries to the AFT, remove entries from the AFT, and change
entries within the AFT. This is accomplished through the Web Agent
interface or CLI commands. A user can also make an entry or
entries static, which saves the entries upon module reset.
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