3com 3031 Instruccion De Instalación

C

HAPTER

 16: L

OGIC

 I

NTERFACE

 C

ONFIGURATION

When needed, the system can automatically create a virtual interface and operate 
it with the parameters of the associated virtual-template. Therefore, manual 
creation and configuration are not needed.  A virtual interface can be deleted due 
to the disconnection of the bottom layer link or the interruption of the user.

Execute the following command in any view to display the state of a specified 
virtual-template.

Before isolating the faults of a virtual-template, you must make sure the 
application environment, specifically, whether the virtual-template is used for 
creating a VPN virtual interface or for creating an MP virtual interface.

Fault 1: The system failed to create a virtual interface.

Problem solving: Such a problem may arise because:

■

The virtual-template had not been assigned with an IP address. Therefore, the 
virtual interface failed to pass the PPP negotiation and hence could not go up.

■

The virtual-template had not been configured with the IP address (or IP address 
pool) intended for the peer. Therefore, if it is necessary to allocate address for 
the peer, the associated virtual interface could not satisfy the requirements of 
the peer and hence could not go up.

■

PPP authentication parameters were incorrectly set. If the peer was not a user 
defined on the router, PPP negotiation would also fail.

This section describes the configuration of the Virtual Ethernet Interface.

Virtual Ethernet interface (VE) is a logical interface that is implemented on the 
interface card. It is primarily application to Point to point Protocol over Ethernet 
over ATM (PPPoEoA).

PPPoEoA adopts a three-layer architecture, with the top layer encapsulated with 
PPP, the mid-layer with PPPoE (PPP over Ethernet), and the bottom layer with 
PPPoE over ATM.

Typically, PPPoE is applied to the community broadband access and to the 
application in which multiple hosts share a front-end bridging access device. The 
PPP parameters carried over the Ethernet are implemented on the interface card of 
the access device via Virtual Ethernet interface. For accessing a remote access 
server (for the purpose of accessing an external network) via this device, the ATM 
PVC must be adopted due to the long distance involved. In this case, the ATM port 
on the server is required to carry the Ethernet packets, which is called PPPoEoA.

For details, refer to Part IV “Link Layer Protocol”.

Table 252   Displaying the state of a specified virtual-template

Display the state of a specified 
virtual-template