By default, all ports are set as untagged members of VLAN 1 with all ports configured as PVID = 1. Every VLAN is assigned a unique VLAN identifier (VID) that distinguishes it from all other VLANs. All incoming packets are assigned to VLAN 1 by the default port VLAN identifier (PVID =1). Untagged packets enter and leave the switch unchanged.
Untagged packets are marked (tagged) as they leave the switch through a tagged port, which is a tagged member of a VLAN. Untagged packets remain unchanged as they leave the switch through an untagged port, which is an untagged member of a VLAN.
VLAN Config Control on ERS
Specifies the VLAN configuration control options. The available options are:
• automatic—This selection automatically adds an untagged port to a new VLAN and automatically removes it from any previous VLAN membership. The PVID of the port is automatically changed to the VID of the VLAN it joins. Since the port is first added to the new VLAN and then removed from any previous membership, the Spanning Tree Group participation of the port is not disabled as long as the VLANs involved are in the same Spanning Tree Group.
• autopvid—This selection functions in the same manner as previous AutoPVID functionality. When an untagged port is added to a new VLAN, the port is added to the new VLAN and the PVID assigned to the new VID without removing it from any previous VLAN memberships. Using this option, an untagged port can have membership in multiple VLANs.
• flexible—This selection functions in a similar manner to disabling AutoPVID functionality. When this option is used, an untagged port can belong to an unlimited number of VLANs. Any new additions of an untagged port to a new VLAN does not change the PVID of that port.
• strict—The factory default, this selection restricts the addition of an untagged port to a VLAN if it is already a member of another VLAN. To add an untagged port to a new VLAN, the switch administrator must remove the port from all other VLANs of which it is a member before adding it to the new VLAN. The PVID of the port is changed to the new VID to which it was added.