Indicates the VLAN forwarding policy.
Options:
1. vlanMac(1) -indicates forwarding based on the VLAN+MAC.
2. vlanConnect(2) -indicates forwarding based on the SVLAN+CVLAN.
During the creation of a VLAN, if this leaf is not specified,
vlanMac(1) is adopted by default. You can perform the set
operation on this leaf to modify the VLAN forwarding policy.
The VLAN forwarding policy can also be configured in
hwForwardingMode of hwVlanSrvProfTable. If a VLAN service profile
is bound to the VLAN, the configuration in the VLAN service profile
takes effect.