218Before configuring one-to-two VLAN mapping, create the CVLAN and the SVLAN.The MTU of an interface is 1500 bytes by default. After a VLAN tag is added to a packet, the packetlength is added by 4 bytes. When you configure one-to-two VLAN mapping, H3C recommends that youset the MTU to a minimum of 1504 bytes on interfaces in the service provider network.To configure one-to-two VLAN mapping:Step Command Remarks1. Enter system view. system-view N/A2. Enter Layer 2 Ethernetinterface view or Layer 2aggregate interface view.• Enter Layer 2 Ethernet interfaceview:interface interface-typeinterface-number• Enter Layer 2 aggregate interfaceview:interface bridge-aggregationinterface-numberN/A3. Configure the link type of theport as hybrid. port link-type hybrid By default, the link type of aport is access.4. Assign the port to theCVLANs.port hybrid vlan vlan-id-list { tagged |untagged }By default, a hybrid port is anuntagged member of theVLAN to which the portbelongs when its link type isaccess.5. Assign the port to the SVLANsas an untagged member. port hybrid vlan vlan-id-list untaggedBy default, a hybrid port is anuntagged member of theVLAN to which the portbelongs when its link type isaccess.6. Configure a one-to-two VLANmapping.vlan mapping nest { rangevlan-range-list | single vlan-id-list }nested-vlan vlan-idBy default, no VLAN mappingis configured on an interface.Only one SVLAN tag can beadded to packets from thesame CVLAN. To add differentSVLAN tags to differentCVLAN packets, execute thiscommand multiple times.Configuring two-to-two VLAN mappingConfigure two-to-two VLAN mapping on the customer-side port of an edge device that connects two SPnetworks, for example, on PE 3 in Figure 56. Two-to-two VLAN mapping enables two sites in differentVLANs to communicate at Layer 2 across two service provider networks that use different VLANassignment schemes.Before configuring two-to-two VLAN mapping, create the original VLANs and the translated VLANs.To configure two-to-two VLAN mapping:
