User`s guide

DGS-3100 Gigabit Ethernet Switch Manual
72
config fdb aging_time
Purpose To set the aging time of the forwarding database.
Syntax
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config fdb aging_time <value 10-6
Description The config fdb aging_time command sets the aging time of the
forwarding database. The aging
time affects the learning process of
se
g time
n a high percentage of received packets whose source
.
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 0 to 630 minutes with a default value of
5 minutes. A very long aging time can result in dynamic forwarding
table entries that
are out-of-date or no longer exist. This may cau
incorrect packet forwarding decisions by the Switch. If the agin
is too short however, many entries may be aged out too soon. This
will result i
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 <value 0-630> − The aging time for the MAC address forwarding
database value, in minutes.
Restrictions Only administrator-level users can issue this command.
Example usage:
To set the fdb aging time:
GS3100# config fdb aging_time 300
D
Success.
DGS3100#
delete fdb
Purpose abase. To delete an entry in the Switch’s forwarding dat
Syntax
delete fdb <vlan_name 32> <macaddr>
Description the Switch’s MAC The delete fdb command deletes an entry in
address forwarding database.
Parameters on which the MAC
from the forwarding
<vlan_name 32> − The name of the VLAN
address resides.
<macaddr> − The MAC address to be removed
table.
Restrictions s command. Only administrator-level users can issue thi
Example usage:
To delete a perman
00#
ent FDB entry:
DGS3100# delete fdb default 00-00-00-00-01-02
Success.
DGS31