Configuring The Mac Address Table; Overview; How A Mac Address Table Entry Is Created - HP 6600 Configuration Manual

Configuring the MAC address table

This book covers only the unicast MAC address table. For information about configuring static multicast
MAC address table entries, see IP Multicast Configuration Guide. For information about MAC address
table configuration in VPLS, see MPLS Configuration Guide.
The MAC address table configuration tasks can be performed in any order.
The MAC address table is available on only SAP modules that are operating in bridge mode.

Overview

To reduce single-destination packet flooding in a switched LAN, an Ethernet device uses a MAC address
table for forwarding frames. This table describes from which port a MAC address (or host) can be
reached. When forwarding a single-destination frame, the device first looks up the destination MAC
address of the frame in the MAC address table for a match. If the device finds an entry, it forwards the
frame out of the outgoing port in the entry. If the device does not find an entry, it floods the frame out of
all but the incoming port.
To view MAC address table information, use the display mac-address command, as follows:
<Sysname> display mac-address
MAC ADDR
000f-e201-0101
--- 1 mac address(es) found

How a MAC address table entry is created

The device automatically learns entries in the MAC address table, or you can add them manually.
MAC address learning
The device can automatically populate its MAC address table by learning the source MAC addresses of
incoming frames on each port.
When a frame arrives at a port, Port A, for example, the device performs the following tasks:
1. Verifies the source MAC address (for example, MAC-SOURCE) of the frame.
2. Looks up the source MAC address in the MAC address table.
3. Updates an entry if it finds one. If the device does not find an entry, it adds an entry for
MAC-SOURCE and Port A.
The device performs this learning process each time it receives a frame from an unknown source MAC
address, until the MAC address table is fully populated.
After learning a source MAC address, when the device receives a frame destined for MAC-SOURCE, the
device finds the MAC-SOURCE entry in the MAC address table and forwards the frame out of Port A.
VLAN ID STATE
1 Config static
---
PORT INDEX
GigabitEthernet4/0/1
1
AGING STATE
NOAGED