64CHAPTER 8: SETTING UP VIRTUAL LANS
VLANs: Tagged and Your Switch supports 802.1Q VLAN tagging, a system that allows traffic Untagged for multiple VLANs to be carried on a single physical (backbone) link.
Membership
When setting up VLANs you need to understand when to use untagged and tagged membership of VLANs. Quite simply, if a port is in a single VLAN it can be an untagged member but if the port needs to be a member of multiple VLANs tagged membership must be defined. Typically endstations (for example, clients or servers) will be untagged members of one VLAN, while
The IEEE 802.1Q standard defines how VLANs operate within an open
To carry multiple VLANs across a single physical (backbone) link, each packet must be tagged with a VLAN identifier so that the Switches can identify which packets belong in which VLANs. To communicate between VLANs a router must be used.
Placing a Port in a Once the information for a new VLAN has been defined, you can place a Single VLAN port in that VLAN.
Creating an IEEE 802.1Q Tagged Link
This method of tagging is defined in the IEEE 802.1Q standard, and allows a link to carry traffic for any of the VLANs defined on your Switch. 802.1Q tagging can only be used if the devices at both ends of a link support IEEE 802.1Q.
To create an 802.1Q tagged link:
1Ensure that the device at the other end of the link uses the same 802.1Q tags as your Switch, that is, the same VLAN IDs are configured (note that VLAN IDs are global across the network).
2Place the Switch ports in the required VLANs as tagged members.
3Place the port at the other end of the link as a tagged member of the same VLANs as the port on your Switch.