VT and VA Interface 535n Before removing a VT, make sure that all the virtual interfaces derived from the VTare removed and the VT is not being used.Configure VT operation parametersCompared to normal physical interfaces, a VT supports only PPP on the link layerand IP on the network layer. You can configure the following operationparameters for a VT:■ Operation parameters for PPP■ IP address of a virtual interface■ IP address (or IP address pool) to be assigned to the PPP peerFor the detailed configuration information, refer to “PPP and MP Configuration”on page 363.Associate a VT with relevant physical interfacesWhen necessary, the system will automatically create VA interfaces, which willadopt the parameters defined in a specific VT. You need not create and configureVA interfaces manually. VA interfaces will be removed due to underlying layerdisconnection or user intervention.In VPN implementations, you need to associate layer-2 tunneling protocol (L2TP)with a VT. Refer to the “L2TP Configuration” on page 1601 for details. In MPimplementations, you need to associate MP users with a VT. Refer to “PPP and MPConfiguration” on page 363 for detailed information.Displaying andMaintaining VTs and VAInterfacesAfter the above configuration, you can use the display command in any view toview the configuration information about the VTs and VA interfaces, so as to verifythe configuration.Create a VT and enter VT view interface virtual-templatenumberRequiredIf the specified VT does notexist, this command firstcreates the VT and thenenters the VT view.Set the maximum number oflinks that can send multicastor broadcast packets in a VTbroadcast-limit link number OptionalBy default, up to 30 links in aVT can send multicast orbroadcast packets.Table 30 Create a VTOperation Command DescriptionTable 31 Display VTs and VA interfacesOperation CommandDisplay the status of thespecified VTdisplay interface virtual-template numberDisplay the status of the VAinterfacedisplay virtual-access [ dialer dialer-number | vtvt-number | user user-name | peer peer-address |va-number ]*
