Mac address table lifetime

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Jun 22nd, 2009
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In catalist switch mac address table aging time = 300 sec (by def, and we dont change it). But on practice, we observe that mac address stay more than 5 min in this table (appr - 9,5 min)!

why this occurs?!

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davy.timmermans Tue, 06/23/2009 - 02:48
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if I'm correct, the "timer" is renewed when a packet arrives for the respective source MAC address.

If a link goes down, the MAC address is immediately flushed.

umbrellaart Tue, 06/23/2009 - 03:17
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Yes, its correct.

We have 2 switch and trunk between them.

Connect PC to switch-1, and it mac address is known on switch-2 on trunk port.Disconnect PC and mac address immediatly flush in switch-1 table,but stay known in switch 2 table on trunk port.

in theories PC mac address from table(switch-2) will disappear through 5 mines,but on practice.....

davy.timmermans Tue, 06/23/2009 - 11:14
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and the output of 'show mac-address-table aging' is probably the default of 300?

umbrellaart Tue, 06/23/2009 - 22:36
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####>sh mac-address-table aging-time

Global Aging Time: 300

Vlan Aging Time

---- ----------

ALL 300


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