DES-3500 Layer 2 Fast Ethernet Switch CLI Reference Manual
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config fdb aging_time
Purpose
Used to set the aging time of the forwarding database.
Syntax
config fdb aging_time <sec 10-1000000>
Description
The aging time affects the learning process of the Switch. Dynamic
forwarding table entries, which are made up of the source MAC
addresses and their associated port numbers, are deleted from the
table if they are not accessed within the aging time. The aging time
can be from 10 to 1000000 seconds with a default value of 300
seconds. A very long aging time can result in dynamic forwarding
table entries that are out-of-date or no longer exist. This may cause
incorrect packet forwarding decisions by the Switch. If the aging time
is too short however, many entries may be aged out too soon. This
will result in a high percentage of received packets whose source
addresses cannot be found in the forwarding table, in which case the
Switch will broadcast the packet to all ports, negating many of the
benefits of having a switch.
Parameters
<sec 10-1000000>
−
The aging time for the MAC address forwarding
database value. The value in seconds may be between 10 and
1000000 seconds.
Restrictions
Only Administrator and Operator-level users can issue this
command.
Example usage:
To set the fdb aging time:
DES-3526:admin#config fdb aging_time 300
Command: config fdb aging_time 300
Success.
DES-3526:admin#
delete fdb
Purpose
Used to delete an entry to the Switch’s forwarding database.
Syntax
delete fdb <vlan_name 32> <macaddr>
Description
This command is used to delete a previous entry to the Switch’s
MAC address forwarding database.
Parameters
<vlan_name 32>
−
The name of the VLAN on which the MAC
address resides.
<macaddr>
−
The MAC address that will be added to the forwarding
table.
Restrictions
Only Administrator and Operator-level users can issue this
command.
Example usage:
To delete a permanent FDB entry:
DES-3526:admin#delete fdb default 00-00-00-00-01-02
Command: delete fdb default 00-00-00-00-01-02
Success.
DES-3526:admin#