228
C
HAPTER
28: MAC A
DDRESS
T
ABLE
M
ANAGEMENT
c
CAUTION:
For a MAC address entry to be added, the port specified by the
interface
keyword must belong to the VLAN specified by the
vlan
keyword in the
command. Otherwise, the entry will not be added.
Setting the Aging Time
for MAC Address Entries
Setting aging time properly helps implement effective MAC address aging. The
aging time that is too long or too short results in a large amount of broadcast
packets wandering across the network and decreases the performance of the
switch.
■
If the aging time is too long, excessive invalid MAC address entries maintained
by the switch may fill up the MAC address table. This prevents the MAC
address table from varying with network changes in time.
■
If the aging time is too short, the switch may remove valid MAC address
entries. This decreases the forwarding performance of the switch.
This command is used in system view and applies to all ports. Aging applies to only
dynamic MAC addresses that are learnt or configured to age.
Normally, you are recommended to use the default aging time, namely, 300
seconds. The
no-aging
keyword specifies that MAC address entries do not age
out.
Setting the Maximum
Number of MAC
Addresses a Port Can
Learn
The MAC address learning mechanism enables an Ethernet switch to acquire the
MAC addresses of the network devices on the segment connected to the ports of
the switch. The switch directly forwards the packets destined for these MAC
addresses. An oversized MAC address table may decrease the forwarding
performance of the switch.
By setting the maximum number of MAC addresses that can be learnt from
individual ports, you can control the number of the MAC address entries the MAC
address table can dynamically maintains. If you have set the maximum number of
MAC addresses that a port can learn to
count
, the port stops learning MAC
addresses when the number of MAC addresses learned by the port reaches
count
.
Table 154
Add a MAC address entry
Operation Command Description
Enter system view
system-view
-
Add a MAC address entry
mac-address
{
static
|
dynamic
}
mac
-
address
interface
interface
-
type
interface-number
vlan
vlan
-
id
Required
Table 155
Set aging time for MAC address entries
Operation Command
Description
Enter system view
system-view
-
Set the aging time of
MAC address entries
mac-address timer
{
aging
age
|
no-aging
}
Required
The default aging time is 300
seconds.
Summary of Contents for Switch 7757
Page 32: ...32 CHAPTER 1 CLI OVERVIEW...
Page 70: ...70 CHAPTER 5 LOGGING IN USING MODEM...
Page 76: ...76 CHAPTER 7 LOGGING IN THROUGH NMS...
Page 86: ...86 CHAPTER 9 CONFIGURATION FILE MANAGEMENT...
Page 120: ...120 CHAPTER 13 ISOLATE USER VLAN CONFIGURATION...
Page 126: ...126 CHAPTER 14 SUPER VLAN...
Page 136: ...136 CHAPTER 16 IP PERFORMANCE CONFIGURATION...
Page 152: ...152 CHAPTER 17 IPX CONFIGURATION...
Page 164: ...164 CHAPTER 19 QINQ CONFIGURATION...
Page 172: ...172 CHAPTER 21 SHARED VLAN CONFIGURATION...
Page 182: ...182 CHAPTER 22 PORT BASIC CONFIGURATION...
Page 198: ...198 CHAPTER 24 PORT ISOLATION CONFIGURATION...
Page 208: ...208 CHAPTER 25 PORT SECURITY CONFIGURATION...
Page 224: ...224 CHAPTER 27 DLDP CONFIGURATION...
Page 232: ...232 CHAPTER 28 MAC ADDRESS TABLE MANAGEMENT...
Page 240: ...240 CHAPTER 29 CENTRALIZED MAC ADDRESS AUTHENTICATION CONFIGURATION...
Page 280: ...280 CHAPTER 30 MSTP CONFIGURATION...
Page 348: ...348 CHAPTER 35 IS IS CONFIGURATION...
Page 408: ...408 CHAPTER 39 802 1X CONFIGURATION...
Page 412: ...412 CHAPTER 40 HABP CONFIGURATION...
Page 422: ...422 CHAPTER 41 MULTICAST OVERVIEW...
Page 426: ...426 CHAPTER 42 GMRP CONFIGURATION...
Page 480: ...480 CHAPTER 47 PIM CONFIGURATION...
Page 506: ...506 CHAPTER 48 MSDP CONFIGURATION...
Page 552: ...552 CHAPTER 51 TRAFFIC ACCOUNTING CONFIGURATION...
Page 570: ...570 CHAPTER 53 HA CONFIGURATION...
Page 582: ...582 CHAPTER 54 ARP CONFIGURATION SwitchA arp protective down recover interval 200...
Page 622: ...622 CHAPTER 58 DHCP RELAY AGENT CONFIGURATION...
Page 684: ...684 CHAPTER 61 QOS CONFIGURATION...
Page 718: ...718 CHAPTER 63 CLUSTER...
Page 738: ...738 CHAPTER 67 UDP HELPER CONFIGURATION...
Page 752: ...752 CHAPTER 69 RMON CONFIGURATION...
Page 772: ...772 CHAPTER 70 NTP CONFIGURATION...
Page 796: ...796 CHAPTER 72 FILE SYSTEM MANAGEMENT...
Page 802: ...802 CHAPTER 73 BIMS CONFIGURATION...
Page 814: ...814 CHAPTER 74 FTP AND TFTP CONFIGURATION...
Page 830: ...830 CHAPTER 75 INFORMATION CENTER...
Page 836: ...836 CHAPTER 76 DNS CONFIGURATION...
Page 852: ...852 CHAPTER 77 BOOTROM AND HOST SOFTWARE LOADING...
Page 858: ...858 CHAPTER 78 BASIC SYSTEM CONFIGURATION DEBUGGING...