I am still new to VLANs and the concept, so please bear with me…
We have a core switch to handle all of our traffic, then other switches are connected to the core switch from different areas of the building. I'd like to use VLANs for different areas, but it includes devices that cannot add a VLAN tag to the packets (i.e. printers).
If I set the Uplink Port (usually Ports 1&2) to be TAGGED VLANs for all the VLANs I need, can I set certain ports goign to devices to be UNTAGGED, and have the traffic route through the correct VLAN?
Core Switch ==========Switch 01
VID 1,10,20,... P1/2 - TAGGED VLAN 1,10,20,...
P5 - UNTAGGED VLAN 10 <== Will this get tagged when it leaves?
Best Answer
Short answer: Yes
Tagged and untagged frames are different formats. The switch will convert from one to the other as necessary.
When you set a port to "Untagged VLAN 10" (switchport access vlan 10 in Cisco-speak), a frame entering that port is associated with VLAN 10. If the frame is forward out a port that is tagged, the frame is converted to 802.1q format, which includes a VLAN tag.
The process also happens the other way: a frame received on a trunk port with a VID of 10 will be forwarded out the untagged port as a "regular" Ethernet frame.