Asymmetric vlan or Multinetting?

[biltmorecomm.com]

How can I configure a 3750 to work with an asymmetric vlan configuration? I have three VLANs that are untagged on a common port, but all

the return traffic is tagged with a PVID of only one of the three VLANs. This functions properly on an Extreme Networks platform configured for multinetting, but I would prefer to start using Cisco 3750s.

[pradeepde]

The Catalyst 3750 Metro switch supports 802.1Q tunneling and Layer 2 protocol tunneling, as well as VLAN mapping (VLAN-ID translation).

When you configure 802.1Q tunneling, you should always use an asymmetrical link between the customer device and the edge switch, with the customer device port configured as an 802.1Q trunk port and the edge switch port configured as a tunnel port.

Assign tunnel ports only to VLANs that are used for tunneling.Configuration requirements for native VLANs and maximum transmission units (MTUs) are explained in this sections below

http://www.cisco.com/en/US/products/hw/switches/ps5532/products_configuration_guide_chapter09186a00801ee9e0.html