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Community Member

tagged and untagged port

how to configure tagged and untagged port in cisco 4500switch? GSM. (00 216) 93 124 999/ 22 741 725

Hello, Not sure what you mean



Not sure what you mean but remember that tags only flow over Trunk links,


Now if you want a specific subnet/vlan to be untagged then just make sure it's the native VLAN.


Makes sense?




Julio Carvajal
Senior Network Security and Core Specialist
Community Member

hello  ok thank you julio,



ok thank you julio,


but can you explain with an example of configurations


regards. GSM. (00 216) 93 124 999/ 22 741 725
Cisco Employee

Hi,I am not going to you use


I am not going to you use your diagram just explaining here:

Below explanation in layman term:


Access Port---Means untagged port. 

Int f0/1

Switchport mode access

Switchport access vlan 10 >> Which means the port is part of vlan 10 and its in untagged state.


Trunk Port--Means Tagged Port:

Int G0/1

Switchport mode trunk

Switchport trunk allowed vlan 10 >>> Which means that if the trunk is up and working fine the packet going out of this interface would have tag on it with vlan 10. Trunk port - frames will be sent with VLAN tag. If only one VLAN allowed, then only frames with allowed vlan tag will be sent


Switchport trunk allowed native vlan 20  >>> Which means that the packet though it is passing through the trunk port but still it would not be tagged.



Another way of explaining this would be:

A trunk allows pretagged packets to passthrough without changing the tag while an access port takes the packets it receives and retags them.


Ex.  To setup a trunk to allows all vlans(pretagged) traffic to flow to and from it


int fa0/0

switchport mode trunk <------ explicitly making this port a trunk rather than allowing it to "negotiate" its role (only command needed)


Ex.  To setup an access port and telling to tag the traffic as vlan 10


int f0/1

switchport mode access <----- explicitly making this an access port rather than allowing it to "negotiate" its role

switchport access vlan 10  <--------- tell this interface to tag any traffic entering the port as vlan 10



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