Loading ...
Loading ...
Loading ...
72
Mode Indicates if Limit Control is globally enabled or disabled on the switch. If globally
disabled, other modules may still use the underlying functionality, but limit checks
and corresponding actions are disabled.
Aging Enabled If checked, secured MAC addresses are subject to aging as discussed under Aging
Period .
Aging Period If Aging Enabled is checked, then the aging period is controlled with this input. If
other modules are using the underlying port security for securing MAC addresses,
they may have other requirements to the aging period. The underlying port security
will use the shorter requested aging period of all modules that use the functionality.
The Aging Period can be set to a number between 10 and 10,000,000 seconds.
To understand why aging may be desired, consider the following scenario: Suppose
an end-host is connected to a 3rd party switch or hub, which in turn is connected to a
port on this switch on which Limit Control is enabled. The end-host will be allowed to
forward if the limit is not exceeded. Now suppose that the end-host logs off or powers
down. If it wasn't for aging, the end-host would still take up resources on this switch
and will be allowed to forward. To overcome this situation, enable aging. With aging
enabled, a timer is started once the end-host gets secured. When the timer expires,
the switch starts looking for frames from the end-host, and if such frames are not
seen within the next Aging Period, the end-host is assumed to be disconnected, and
the corresponding resources are freed on the switch.
Port Configuration
Port The port number to which the configuration below applies.
Mode Controls whether Limit Control is enabled on this port. Both this and the Global Mode
must be set to Enabled for Limit Control to be in effect. Notice that other modules
may still use the underlying port security features without enabling Limit Control on a
given port.
Limit The maximum number of MAC addresses that can be secured on this port. This
number cannot exceed 1024. If the limit is exceeded, the corresponding action is
taken.
The switch is "born" with a total number of MAC addresses from which all ports draw
whenever a new MAC address is seen on a Port Security-enabled port. Since all
ports draw from the same pool, it may happen that a configured maximum cannot be
granted, if the remaining ports have already used all available MAC addresses.
Action If Limit is reached, the switch can take one of the following actions:
None: Do not allow more than Limit MAC addresses on the port, but take no further
action.
Trap
: If Limit + 1 MAC addresses is seen on the port, send an SNMP trap. If Aging is
Loading ...
Loading ...
Loading ...