Hi,

In 802.1Q trunking, all VLAN packets are tagged on the trunk link, except the native VLAN. The native VLAN packets are sent untagged on the trunk link. Therefore, the native VLAN should be the same on both switches configured for trunking. This way, you can deduce to which VLAN a frame belongs when you receive a frame with no tag. By default, VLAN 1 is the native VLAN on all switches.

HTH, please do rate all helpful replies,

Mohammed Mahmoud.