04-05-2009 07:50 AM - edited 03-06-2019 05:00 AM
Going over some other questions this morning, I ran into one I had myself but forgot to ask...say we have:
interface FastEthernet1/0/1
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 3,4,6-9,300
switchport mode trunk
---
When you have the cmd
sw mo tr
doesnt that mean all VLANs are allowed? By having the line
switchport trunk allowed vlan 3,4,6-9,300
Is this config not allowing all other VLANs?
Thanks
Solved! Go to Solution.
04-05-2009 08:16 AM
Hello:
By default, a dot1q trunk configured on a Cisco device will allow all vlans that are configured on the switch.
You can prune some vlans off the trunk by using the "allowed" keyword.
"doesnt that mean all VLANs are allowed?"
Yes.
"By having the line switchport trunk allowed vlan 3,4,6-9,300 Is this config not allowing all other VLANs?"
Correct. Only vlans 3,4,6,7,8,9 and 300 will be allowed on that trunk.
HTH
Victor
04-05-2009 08:16 AM
Hello:
By default, a dot1q trunk configured on a Cisco device will allow all vlans that are configured on the switch.
You can prune some vlans off the trunk by using the "allowed" keyword.
"doesnt that mean all VLANs are allowed?"
Yes.
"By having the line switchport trunk allowed vlan 3,4,6-9,300 Is this config not allowing all other VLANs?"
Correct. Only vlans 3,4,6,7,8,9 and 300 will be allowed on that trunk.
HTH
Victor
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide