Cisco CCNA VLANs and 802.1Q Trunking 2

Question 1

What is the valid VLAN ID range for extended VLANs on a Cisco switch?

Accepted Answer

1006–4094

Answer

Extended VLANs use IDs 1006–4094, while normal-range VLANs span 1–1005.

Question 2

Which command verifies the trunking status and allowed VLANs on interface Gi0/1?

Accepted Answer

show interfaces Gi0/1 trunk

Answer

`show interfaces Gi0/1 trunk` displays trunking mode, encapsulation, and the allowed VLAN list.

Question 3

A port is configured with `switchport mode dynamic desirable`. What will happen if the neighboring port is set to `switchport mode access`?

Accepted Answer

The port becomes an access port

Answer

Dynamic desirable will form a trunk only if the neighbor also negotiates trunking; an access-mode neighbor causes it to become an access port.

Question 4

Which 802.1Q field identifies the VLAN to which a frame belongs?

Accepted Answer

VLAN ID (VID)

Answer

The 12-bit VLAN Identifier (VID) field in the 802.1Q tag specifies the VLAN.

Question 5

What happens to traffic from a VLAN that has been pruned from a trunk link?

Accepted Answer

It is not forwarded across that trunk

Answer

VTP pruning or manual pruning removes a VLAN from a trunk so its traffic is not flooded unnecessarily across that link.

Cisco CCNA Practice Test