Determining Requirements for Your Configuration Type

Solaris PPP supports many configuration options, including:

• Remote computer-to-network over a point-to-point link

• Remote computer-to-remote computer over a point-to-point link

• Network-to-network over a point-to-point link

• Dial-in server-to-multiple remote computers through one or more dynamic point-to-point links

• Dial-in server-to-multiple remote computers through a multipoint link

• Multiple remote computers comprising a virtual network, all communicating through multipoint links

These configurations are introduced in "Extending Your Network With PPP".

This section describes the information you need to gather and tasks you have to perform for each configuration type before beginning the configuration process. Read the section that describes the configuration you want to set up.

Areas you need to consider are:

• Network interface

• Addressing method

• Name service used, if any

• Dial-in as well as dial-out support

• Routing requirements

Remote Computer-to-Network Configuration

The remote computer-to-network is the most common asynchronous PPP configuration. Use it to configure machines in remote offices or users' homes that dial out over a point-to-point PPP link to a dial-in server on a network.

• Network interface - This point-to-point link uses the ipdptpn virtual network interface. You need to specify it in the configuration files of all remote machines that dial out to a network.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that communicate over the link. For remote hosts, you should use existing host names and IP addresses. Refer to "Determining IP Addressing for Your PPP Link" for complete details.

• Name service - NIS and NIS+ name services are not recommended for remote hosts. These services generate a great deal of network traffic, often at unexpected times. The DNS name service is more efficient for this type of configuration. You might want to set up DNS, as described in Solaris Naming Administration Guide, on each remote host. If you don't use DNS, PPP accesses the /etc/inet/hosts file on the remote machine.

• Dial-in and dial-out support - Remote hosts usually implement dial-out communications only. They do not allow other machines to dial in to them directly. Therefore, you must update the UUCP files on each to support dial-out communications, as explained in "Editing UUCP Databases".

• Routing requirements - Because RIP is part of the Solaris TCP/IP protocol stack, it runs by default on remote hosts. Turn off RIP to improve performance, if necessary, and instead use static routing. See "Routing Protocols" and "Turning Off RIP" for details.

Remote Host-to-Remote Host Configuration

Use the host-to-host configuration to establish point-to-point communications between two remote hosts in different physical locations. This configuration is useful for two standalone machines in remote offices that need to exchange information. No physical network is involved.

• Network interface - This basic point-to-point link uses the ipdptpn virtual network interface. You must specify the interface in the configuration files of both endpoints.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that can communicate over the link. Use the existing host names and the IP addresses assigned to the primary network interface, if they already exist. Otherwise, create IP addresses for the endpoints. Refer to "Determining IP Addressing for Your PPP Link" for complete details.

• Name service - Because only two peer hosts are involved, you don't need a true name service. The /etc/inet/hosts files on both peer hosts are used for address resolution.

• Dial-in and Dial-out support - Both machines need to perform dial-in and dial-out operations. You must modify the UUCP databases and /etc/passwd on both endpoints.

• Routing requirements - Because RIP is part of the Solaris TCP/IP protocol stack, it runs by default on remote hosts. Turn off RIP to improve performance, if necessary, and instead use static routing. See "Routing Protocols" and "Turning Off RIP" for details.

Network-to-Network Configuration

Use the network-to-network PPP configuration to create an internetwork joining two networks in physically separate locations. In this case, modems and PPP software function as the router connecting the networks.

• Network interface - The point-to-point link uses the ipdptpn virtual network interface. You must specify ipdptpn in the configuration files for both endpoint machines joining the two networks.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that communicate over the link. Two possible addressing scenarios exist for this type of configuration; they are explained in "Determining IP Addressing for Your PPP Link".

• Name service - NIS and NIS+ name services can function over this type of PPP link; however, each network should be a separate domain. If you use DNS, both networks can be part of a single domain. Refer to Solaris Naming Administration Guide for details. If you use local files for name service, the /etc/inet/hosts files on both endpoint machines are used for address resolution. They must contain the host names and IP addresses of every host on each network that can communicate over the link.

• Dial-in and Dial-out support - Both network endpoint machines need to perform dial-in and dial-out operations, so you should update their UUCP and /etc/passwd files.

• Routing requirements - The endpoints in a network-to-network link usually run RIP in order to exchange routing information. Do not disable RIP for this configuration.

Dial-in Server With Dynamic Point-to-Point Links

A dynamic point-to-point link is one of two types of configurations that you can use for a dial-in server functioning as the network endpoint that remote hosts access. In this configuration scheme, the server connects to its remote hosts over a dynamically allocated point-to-point link. The dial-in server uses its dynamic links on an as-needed basis to establish communications with the remote hosts it serves.

• Network interface - The dynamic point-to-point link uses the ipdptp* virtual network interface with an asterisk wildcard character. The asterisk enables the link to be allocated dynamically. You must specify this interface in the configuration file.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that communicate over the link. Refer to "Determining IP Addressing for Your PPP Link" for complete details.

• Name service - Although NIS and NIS+ are not recommended for remote hosts, the dial-in server in a remote host-to-network configuration can be a NIS client on the network to which it is physically connected. If NIS is on the server's physical network, make sure that the NIS maps are updated with the host names and IP addresses of the remote hosts. You can use DNS on the dial-in server and its remote hosts. For more information regarding DNS and name services in general, refer to Solaris Naming Administration Guide. If you use local files for name service, PPP access the /etc/inet/hosts file on the dial-in server for address resolution.

• Dial-in support - You must update the /etc/passwd file on the dynamic point-to-point dial-in server. The dynamic link server does not directly dial out to the remote hosts.

• Routing requirements - Because RIP is part of the Solaris TCP/IP protocol stack, it runs by default on remote hosts. Turn off RIP to improve performance, if necessary, and instead use static routing. See "Routing Protocols" and "Turning Off RIP" for details.

Multipoint Dial-in Server

A multipoint link is one of two types of configurations that you can use for a dial-in server functioning as the network endpoint that remote machines can access. In this configuration scheme, the dial-in server connects to multiple remote hosts over the same multipoint link. The remote hosts always connect to the dial-in server over a point-to-point link, as explained in "Remote Computer-to-Network Configuration".

Use this configuration when you want to define a separate network of remote hosts and their dial-in server.

• Network interface - The multipoint link uses the ipdn virtual network interface. You must specify this interface in the configuration file for the dial-in server.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that communicate over the link. Refer to "Determining IP Addressing for Your PPP Link" for complete details. You must create a separate network for the machines on the multipoint link. See "Assigning a Network Number to the PPP Link" for more information.

• Name service - Although NIS and NIS+ are not recommended for remote hosts, the dial-in server in a remote host-to-network configuration can be a NIS client on the physical network to which it is connected. If NIS is on the server's physical network, make sure that the NIS maps are updated with the host names and IP addresses of the remote hosts. You can use DNS on the dial-in server and its remote hosts. For more information regarding DNS and name services in general, refer to Solaris Naming Administration Guide. If you use local files for name service, PPP uses the /etc/inet/hosts file on the dial-in server for address resolution.

• Dial-in and dial-out support - The multipoint dial-in server functions as a network router between its PPP virtual network and the physical network to which it is connected. It dials out to its remote hosts whenever it receives IP traffic from the physical network destined for its PPP network. Therefore, you must configure the multipoint dial-in server for both dial-in and dial-out support, and update its UUCP and /etc/passwd files.

• Routing requirements - The ipdn interface does not support RIP; you do not need to disable it.

Hosts on a Virtual Network

Use a virtual network configuration to connect three or more physically separated computers into a virtual network of phone lines, modems, and PPP software.

• Network interface - This type of configuration requires a multipoint link, which uses the ipdn virtual network interface. This interface connects each endpoint system with the other endpoints on the virtual network.

• Addressing method - The configuration file must include the host names or IP addresses of the machines that communicate over the link. Refer to "Determining IP Addressing for Your PPP Link" for more information. You must assign a network number to the virtual network. Refer to "Creating a Unique IP Address and Host Name" for complete details.

• Name Service - You can run NIS and NIS+ for the virtual network; however, this can affect the performance of the link. DNS is a better alternative. Refer to Solaris Naming Administration Guide for instructions on setting up these name services. If you use files for the name service, be sure to update /etc/inet/hosts on each machine with the host names and IP addresses of all machines on the virtual network.

• Dial-in and dial-out support - All machines in the virtual network must be configured for both dial-in and dial-out operations, so you should update their UUCP and /etc/passwd files.

• Routing requirements - The ipdn interface does not support RIP; you do not need to disable it.