3Com Router User Manual

Sub-Interface157
Any packet reaching the null interface will be dropped, which provides another 
method for packet filtering: Just sending unnecessary network traffic to Null0 
interface, so that there is no need to configure ACL.
For example: Use static routing configuration command ip route-static 
192.101.0.0 255.255.0.0 null 0 
will drop all the packets sent to network 
segment 192.101.0.0.
2Configure operating parameters of the interface
ip unreachables is the only command which can be configured on...

158CHAPTER 11: CONFIGURING LOGICAL INTERFACE
Configure sub-interfaces of Ethernet interface
1Create and delete Ethernet sub-interfaces
Please use the following commands in all views.
Ta b l e 190   Create and delete Ethernet interface
When using the above commands, if corresponding Ethernet sub-interface has 
been created (the same as sub-number), enter the view of this sub-interface 
directly. Otherwise, first create Ethernet sub-interface with sub-number as the 
specified one, and then enter the view...

Sub-Interface159
■IPX network number which is different from that of the affiliated WAN 
interface, and other IPX working parameters
■Virtual circuit of the sub-interface 
Please see chapters in Operation Manual - Link Layer Protocol and Operation 
Manual - Network Protocol for details about the above configurations. 
Configure sub-interfaces of WAN interface which link layer protocol is X.25
1Create and delete WAN sub-interfaces
The command is the same as above.
2Configure relevant working parameters...

160CHAPTER 11: CONFIGURING LOGICAL INTERFACE
[Router-Serial0]link-protocol fr
3Specify DTE as its frame relay terminal type
[Router-Serial0]fr interface-type dte
4Create sub-interface Serial 0.1 on WAN interface Serial0 of router A in point-to 
point mode, and enter its view
[Router]interface serial 0.1 point-to-point
5Set its IP address to 202.38.160.1 and address mask to 255.255.255.0.
[Router-Serial0.1]ip address 202.38.160.1 255.255.255.0
6Allocate a virtual circuit with DLCI 50 to it....

Virtual-Template and Virtual Interface161
dynamically create a virtual interface based on the configuration parameters of the 
template.
Similarly, after multiple PPP links are bound as MP, a virtual interface also needs to 
be created to exchange data with the opposite end. At this time, select an 
interface template to dynamically create a virtual interface.
Configure 
Virtual-Template In VPN and MP application environments, the system automatically creates and 
deletes virtual interface, which is...

162CHAPTER 11: CONFIGURING LOGICAL INTERFACE
3Create corresponding relation between the virtual-template and related physical 
interface
In VPN application environment, it is necessary to build up corresponding relations 
between L2TP group and virtual-template. In MP application environment, it is 
necessary to build up corresponding relations between MP and virtual-template. 
Please see chapters in Operation Manual – VPN and Operation Manual – Link 
Layer Protocol for detailed description.
Display and...

IV
LINK LAYER PROTOCOL
Chapter 12Configuring PPP and MP
Chapter 13Configuring PPPoE Client
Chapter 14Configuring SLIP
Chapter 15Configuring ISDN Protocol
Chapter 16Configuring LAPB and X.25
Chapter 17Configuring Frame Relay
Chapter 18Configuring HDLC
Chapter 19Configuring Bridge 

164 

12
CONFIGURING PPP AND MP
This chapter contains information on the following topics:
■PPP Overview
■MP Overview
■Configure PPP
■Configure MP
■Display and Debug PPP
■Typical PPP Configuration Example
■Typical MP Configuration Example
■Fault Diagnosis and Troubleshooting of PPP
PPP OverviewThe Point-to-Point Protocol (PPP) provides a standard method for transporting 
multi-protocol datagram over point-to-point links. It gains wide applications since 
it can provide user authentication, support...

166CHAPTER 12: CONFIGURING PPP AND MP
The authenticator sends some randomly generated packets to the requester 
(challenge), and at the same time it sends its configured username to the 
requester.
When the requester receives the challenge, it will look for the user password 
according to the authenticators username and its own user list. If it finds the user 
in the user list with the same name as the authenticators username, the requester 
builds the response with its own password, serial number of...