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Mac address table showing static and dynamic entries

tiwariharish44
Level 1
Level 1

Hi,
 

What is meant by "Static" and "Dynamic" entries in the mac address table of a Cisco 2960 switch when I issue the command-

"Show mac address table"?

Has this something got to do with port security command , but I have not configured any static mac address under the interfaces.

The sho ru interface & sh mac address table  of one of the switch is attached for your reference.

1 Accepted Solution

Accepted Solutions

Krishnendu AR
Level 1
Level 1

Dynamic means the switch learnt the MAC address via dynamic MAC learning. The switch will auto-learn the MAC address associated with a port when it receives layer 2 frames from the machines on a particular switchport. The source MAC address of the frame will be added to the MAC table. The MAC address will be mapped to respective VLAN and the switchport in the MAC address table.

Switch>sh mac  address-table  | i DY
 300    001e.a239.12e3    DYNAMIC     Gi1/0/9
 300    001e.a239.37eb    DYNAMIC     Gi1/0/10
 300    001e.a239.3b27    DYNAMIC     Gi1/0/10
 300    001e.a239.3b42    DYNAMIC     Gi1/0/9
 300    001e.a239.3d3a    DYNAMIC     Gi1/0/4

 

 

Static means the MAC address has been statically added to MAC address table. For example:

switch# configure terminal 
switch(config)# mac-address-table static 12ab.47dd.ff89 vlan 3 interface ethernet 2/1 

View solution in original post

4 Replies 4

Krishnendu AR
Level 1
Level 1

Dynamic means the switch learnt the MAC address via dynamic MAC learning. The switch will auto-learn the MAC address associated with a port when it receives layer 2 frames from the machines on a particular switchport. The source MAC address of the frame will be added to the MAC table. The MAC address will be mapped to respective VLAN and the switchport in the MAC address table.

Switch>sh mac  address-table  | i DY
 300    001e.a239.12e3    DYNAMIC     Gi1/0/9
 300    001e.a239.37eb    DYNAMIC     Gi1/0/10
 300    001e.a239.3b27    DYNAMIC     Gi1/0/10
 300    001e.a239.3b42    DYNAMIC     Gi1/0/9
 300    001e.a239.3d3a    DYNAMIC     Gi1/0/4

 

 

Static means the MAC address has been statically added to MAC address table. For example:

switch# configure terminal 
switch(config)# mac-address-table static 12ab.47dd.ff89 vlan 3 interface ethernet 2/1 

But we have not put any static address command in our switches. Can port security be the reason for mac address showing as static??

Has this something got to do with port security command , but I have not configured any static mac address under the interfaces.

The sho ru interface & sh mac address table  of one of the switch is attached for your reference.

 

rezaalikhani
Level 3
Level 3

I have exactly the same issue...

 

Any ideas?

 

Ilogistikmab
Level 1
Level 1

Static means not only statically added mac addresses but also directly connected devices on the switch you are connected to, e.g. via ssh.

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