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Julio Carvajal Sat, 05/03/2014 - 18:57
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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?




medbarki1 Sun, 05/04/2014 - 02:06
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ok thank you julio,


but can you explain with an example of configurations



InayathUlla Sharieff Sat, 09/13/2014 - 06:54
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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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