221
Switch#show mac-address-table discard
7.4 Typical Configuration Examples
Fig 7-2 MAC Table typical configuration example
Scenario: Four PCs as shown in the above figure connect to port 1/5, 1/7, 1/9, 1/11
of switch, all the four PCs belong to the default VLAN1. As required by the network
environment, dynamic learning is enabled. PC1 holds sensitive data and can not be
accessed by any other PC that is in another physical segment; PC2 and PC3 have static
mapping set to port 7 and port 9, respectively.
The configuration steps are listed below:
1. Set the MAC address 00-01-11-11-11-11 of PC1 as a filter address.
Switch(Config)#mac-address-table static 00-01-11-11-11-11 discard vlan 1
2. Set the static mapping relationship for PC2 and PC3 to port 7 and port 9, respectively.
Switch(Config)#mac-address-table static 00-01-22-22-22-22 interface ethernet 1/7 vlan 1
Switch(Config)#mac-address-table static 00-01-33-33-33-33 interface ethernet 1/9 vlan 1
7.5 Troubleshooting Help
Using the show mac-address-table command, a port is found to be failed to learn the
MAC of a device connected to it. Possible reasons:
)
The connected cable is broken.
)
Spanning Tree is enabled and the port is in “discarding” status; or the device is just
1/7
1/9
1/11
1/5
PC1
MAC 00-01-11-11-11-11
PC4
MAC 00-01-44-44-44-44
PC3
MAC 00-01-33-33-33-33
PC2
MAC 00-01-22-22-22-22