CCNA Cisco Certified Network Associate Study Guide - FTP Server

Cisco 1900 IOS Configuration Commands 589
port, which means that unless you specifically configure a hardware address
to a switch port, it won’t work. Administrators can also create static entries
in the switch; these entries actually create a path for a source hardware
address. This can be really restrictive, and you need to be careful when setting
static entries because you can basically shut your switch down if you do
not plan the configuration carefully.
Setting Permanent MAC Address Entries
You can configure a permanent MAC address to a switch port by using the
global configuration command mac-address-table permanent [macaddress]
[interface].
In the example below, the options are as follows:
Aging-time This can be used to change the age a MAC address is
allowed to stay in the filter table before being cleared.
Permanent This sets a permanent address to an interface. If the user
changes the host NIC card, then the host will not work until you change
the permanent entry address.
Restricted This is used with the static command to set a path for source
hardware addresses. Very restrictive for where a host can send a frame.
To configure a permanent hardware address to an interface, use the command
mac-address-table permanent from global configuration mode, as
shown below:
Todd1900EN#config t
Enter configuration commands, one per line. End with CNTL/Z
Todd1900EN(config)#mac-address-table ?
aging-time Aging time of dynamic addresses
permanent Configure a permanent address
restricted Configure a restricted static address
After you choose the mac-address-table permanent command, add the
hardware address and the interface it is associated with. This will restrict the
interface to only accept frames from this source hardware address.
Todd1900EN(config)#mac-address-table permanent ?
H.H.H 48 bit hardware address
Todd1900EN(config)#mac-address-table permanent
00A0.2448.60A5 e0/4