Dial-in Server With Dynamic Link

When the dial-in server receives an incoming packet, the link manager reads the path sections of its configuration file to identify the remote endpoint and determine the interface to use. The configuration file shown in Example 11-1 does not contain an interface keyword. Instead, the link manager uses interface information established in the defaults section.

The asppp.cf configuration file for a dial-in server with dynamically allocated links might resemble Example 11-1:

Example 11-1 Configuration File for Server With Dynamically Allocated Link

ifconfig ipdptp0 plumb mojave clienta down
ifconfig ipdptp1 plumb mojave clientb down
ifconfig ipdptp2 plumb mojave clientc down

# This means grab whatever interface is available (not in use)
defaults
	    interface ipdptp*

# Each path specifies a machine that might dial up / log
# in to this server

path
    peer_system_name tamerlane   # nomada uses the login name
                                 # tamerlane
	   
path
    peer_system_name lawrence    # nomadb uses the name lawrence
                                 # for login
    
path
    peer_system_name nomadc   

ifconfig Section for Server With Dynamic Links

The ifconfig section for a dial-in server with a dynamically allocated link has the syntax:

ifconfig ipdptpn plumb server-name client-address down

Example 11-1 contains three ifconfig lines, each initializing a point-to-point interface.

ifconfig  ipdptp0  plumb  mojave  clienta  down
ifconfig  ipdptp1  plumb  mojave  clientb  down
ifconfig  ipdptp2  plumb  mojave  clientc  down

defaults Section for Server With Dynamic Links

When you configure a dynamically allocated link, you might want to include a defaults section in the asppp.cf file. This section sets the defaults for the value replacing keyword, wherever keyword subsequently appears in the asppp.cf file. The syntax for the defaults section is:

default 
     keyword

Example 11-1 uses the keyword interface to define the interface as ipdptp*, indicating a dynamic link. The asterisk wildcard tells the link manager to use any available ipdptp interface defined in the ifconfig section. Thus the link manager on server mojave uses either ipdptp0, ipdptp1, or ipdptp2--whichever is the first interface configured "down" that it finds.

path Section for Server With Dynamic Links

The configuration file for the server with dynamic links must contain path sections for every remote host permitted to establish connections with the server. The path section has the following syntax: .

path
    peer_system_name endpoint-username    

No interface keyword has been defined in the path section because this value is defined in the defaults section.The peer_system_name keyword has the same meaning here as it does in the configuration file for the multipoint server. See "path Section for Multipoint Dial-in Server" for more information.

Additional Keywords

You can supply other keywords in the asppp.cf file to define how endpoint machines should communicate, including the use of security keywords as explained in "Configuration Keywords".