HP 6120XG HP ProCurve Series 6120 Blade Switches Advanced Traffic Management G - Page 65

Static Virtual LANs (VLANs) 802.1Q VLAN Tagging Note Each 802.1Q-compliant VLAN must have its own unique VID number, and that VLAN must be given the same VID in every device in which it is configured. That is, if the Red VLAN has a VID of 10 in switch X, then 10 must also be used for the Red VID in switch Y. VID Numbers Figure 2-27. Example of VLAN ID Numbers Assigned in the VLAN Names Screen VLAN tagging gives you several options: ■ Since the purpose of VLAN tagging is to allow multiple VLANs on the same port, any port that has only one VLAN assigned to it can be configured as "Untagged" (the default) if the authorized inbound traffic for that port arrives untagged. ■ Any port with two or more VLANs of the same type can have one such VLAN assigned as "Untagged". All other VLANs of the same type must be configured as "Tagged". That is: Port-Based VLANs Protocol VLANs A port can be a member of one untagged, port-based VLAN. All other port-based VLAN assignments for that port must be tagged. A port can be an untagged member of one protocol-based VLAN of each protocol type. When assigning a port to multiple, protocol-based VLANs sharing the same type, the port can be an untagged member of only one such VLAN. A port can be a tagged member of any port- A port can be a tagged member of any based VLAN. See above. protocol-based VLAN. See above. Note: A given VLAN must have the same VID on all 802.1Q-compliant devices in which the VLAN occurs. Also, the ports connecting two 802.1Q devices should have identical VLAN configurations. 2-42