Problem understanding frame tagging

[Bashar]

This relates to the section on page 561-562.
From my understanding, in order to enable VLAN communication across different switches frames are tagged with a VLAN ID. When a frame reaches a switch it will examine the tag. If this tag matches an access link on the switch, the switch will remove the tag and forward the frame out that access link towards the host that should receive it. If the frame is destined to another switch, the switch will forward the frame out it's trunk link along with the tag.
Yet in the second paragraph of p.562 Todd states that:
"Another thing about trunk ports is that they will support tagged and untagged traffic simultaneously."
If the switch removes the tag (VLAN ID) once the required 'access link' has been reached. How would an untagged frame even reach a trunk link?
Thank you for any help.

[lammle]

Native VLAN's send information out trunked links untagged when using 802.1q. By default you'll find this as your managment VLAN or VLAN 1 on every switch. So basically I was saying that all managment traffic, by default, is untagged.
Todd Lammle

[apsk]

This also relates to the page 561 (last sentences).
p.561 :
“........ .It then finds out what to do with the frame by looking at the information in what’s known as the filter table. If the frame reaches a switch that has another trunked link, the frame will be forwarded out the trunk-link port”.


Question: Do switches with trunked link will always forward frames out the trunk-link port or will do only if the destination address MAC isn’t known in the filter table?


-Thanks for any help :)