Refer to the exhibit.
Which VLANs are permitted to send frames out port FastEthernet0/1?
A.
100 – 200
B.
4 – 100
C.
1 and 4 – 100
D.
3 and 4 – 100
Which VLANs are permitted to send frames out port FastEthernet0/1?
Refer to the exhibit.
Which VLANs are permitted to send frames out port FastEthernet0/1?
Traffic on the native vlan does not get tagged as it crosses a trunk, so there is no dot1q tag in the
first place to be filtered. And you don’t need to allow the native vlan. But if we force to tag the
native vlan (with the “switchport trunk native vlan tag” command) then if the native vlan is not in
the “allowed vlan” list it will be dropped.
Actually, you MUST allow a native vlan on a trunk.
So, answer B is correct.
should no answer be C, access mode vlan is 1? would not this interface carry traffic for VLAN 1 ?
B is correct. If you prune your native vlan, it will not be forwarded. All management like CDP will continue to operate using VLAN 1(even if it’s pruned) but user traffic through the native vlan will not be forwarded.
Prakash, access mode vlan 1 will only be used if the operational mode is access. Since the operational mode is trunk, it will use vlan 1 for untagged traffic if there is no native vlan configured.
answer B is correct. Tested.
As I understand there are Vlan can’t be pruned , Vlan 1, 1002-1005
http://www.cisco.com/c/en/us/support/docs/lan-switching/vtp/10558-21.html#vtp_pruning
SO I believe answer C is the correct one.
I don’t think B is correct as it will be direct answer.
It is about “allowed vlan” and not about “pruning”.
You cannot remove vlan 1, but you can remove it from allowed list.
I opt for “B”.
Tested, answer B is correct. VLAN 1 and 3 won’t pass if they are not allowed on the trunk.
tricky n bad question, it may different from different IOS, I vote D because it looks “alike”
I emulate this question using IOU.
The config for Fa0/1 is
interface Ethernet0/1
switchport
switchport trunk encapsulation dot1q
switchport trunk native vlan 3
switchport trunk allowed vlan 4-100
switchport mode trunk
duplex auto
end
I think B is correct. When I allow vlan 3-100 ping is ok, when I change to 4-100 ping stopped.
In my lab Access port Fa0/0 in vlan 3.