05-17-2008 11:52 AM - edited 03-05-2019 11:03 PM
hi every body!
I want to know can i block nativa vlan 1 by:
switchport trunk encapsulation dot1q
switchport trunk allowed vlan except 1
or
switchport trunk allowed vlan remove 1
Using ISL:
switchport trunk encapsulation isl
switchport trunk allowed vlan except 1
or
switchport trunk allowed vlan remove 1
thanks!
Solved! Go to Solution.
05-17-2008 12:06 PM
You cant remove native vlan from trunk. However, you can change the native vlan from default of 1 to some other vlan number.
"switchport trunk native vlan x"
05-17-2008 12:41 PM
Sarah
As already mentioned you can change the native vlan to be something other than vlan 1. The native vlan is simply the vlan that is sent across a trunk without a tag. By default it is vlan 1.
Cisco recommend using a dummy vlan for the native vlan ie. a vlan that is not routed and has no devices connected into it.
If you make the native vlan a vlan other than vlan 1 it is important to note that vlan 1 will still be used to send DTP,VTP,PagP frames which will be tagged.
You can if you want to make sure that the native vlan is tagged by using the command
vlan dot1q tag native
Jon
05-17-2008 12:06 PM
You cant remove native vlan from trunk. However, you can change the native vlan from default of 1 to some other vlan number.
"switchport trunk native vlan x"
05-19-2008 07:56 AM
thanks for your reply. I applogise for posting multiple instances of same post by mistake.
Have a nice day!
05-17-2008 12:41 PM
Sarah
As already mentioned you can change the native vlan to be something other than vlan 1. The native vlan is simply the vlan that is sent across a trunk without a tag. By default it is vlan 1.
Cisco recommend using a dummy vlan for the native vlan ie. a vlan that is not routed and has no devices connected into it.
If you make the native vlan a vlan other than vlan 1 it is important to note that vlan 1 will still be used to send DTP,VTP,PagP frames which will be tagged.
You can if you want to make sure that the native vlan is tagged by using the command
vlan dot1q tag native
Jon
05-19-2008 07:57 AM
Thanks jon for your reply!
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