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The Point-to-Point Protocol (PPP) is one of several protocols used to enable communication between ISPs and their customers. PPP performs tasks such as the following:
- Identifying the type of service the ISP provides to a given customer
- Identifying the customer to the ISP through a username and password login
- Enabling the ISP to assign Internet information to the customer's computers
PPP can be used only when your connection with your ISP is a routed connection (i.e., it cannot be used for bridged connections). For more information on bridged and routed connections, see the help topic "Configuring the System Mode."
A PPP interface can be either of two types: PPP over ATM (PPPoA) and PPP over Ethernet (PPPoE). Although to the end user they function similarly, the ISP's network may be configured to handle only one protocol type. Furthermore, an ISP may not use the PPP protocol at all, instead offering EoA-type connections. Contact your ISP before changing the preconfigured WAN interface type.
Viewing Your Current PPP Configuration
The Point to Point Protocol (PPP) Configuration page displays a table with basic information about your PPP setup.
A PPP interface is configured as a group of software settings associated with an ATM VC interface. Each PPP interface and is given a name, such as ppp-0, ppp-1, etc. (Users typically need only one PPP interface; in some cases, multiple interfaces are created to allow the user to log on to more than one account with the ISP.)
You can configure the following settings on the PPP Configuration page:
- Inactivity TimeOut...:
The time in minutes that must elapse before a PPP connection times-out due to inactivity. This setting applies only to PPP interfaces that are configured as "start-on-data" interfaces. This type of interface starts up only when it receives data, and then returns to a down state after the specified amount of time. This setting works with the following setting to determine what type of data can activate a start-on-data interface.
- Ignore WAN to LAN traffic...:
When enabled, data traffic traveling in the incoming direction -- from a WAN interface to the LAN interface -- will not count as activity on the WAN port for the purposes of determining whether to make it inactive; i.e., WAN to LAN traffic will not activate a start-on-data interface. Only LAN-to-WAN traffic will start the interface.
The PPP Configuration table displays the following fields:
- Interface:
The predefined name of the PPP interface.
- VC:
The Virtual Circuit over which this PPP data is sent. The VC identifies the physical path the data takes to reach your ISP. See Configuring the ATM VC for more information.
- Interface Sec Type:
The type of Firewall protections that are in effect on the interface (public, private, or DMZ):
- A public interface connects to the Internet (PPP interfaces are typically public). Packets received on a public interface are subject to the most restrictive set of firewall protections defined in the software.
- A private interface connects to your LAN, such as the Ethernet interface. Packets received on a private interface are subject to a less restrictive set of protections, because they originate within the network.
- The term DMZ (de-militarized zone), in Internet networking terms, refers to computers that are available for both public and in-network accesses (such as a company's public Web server). Packets incoming on a DMZ interface -- whether from a LAN or external source -- are subject to a set of protections that is in between public and private interfaces in terms of restrictiveness.
- Protocol:
The type of PPP protocol used. Your ISP may use PPP-over-Ethernet (PPPoE) or PPP-over-ATM (PPPoA).
- WAN IP:
The IP address currently assigned to your WAN (DSL) port by your ISP.
- Gateway IP:
The IP address of the server at your ISP that provides you access to the Internet.
- Default Route:
Indicates whether the ADSL/Ethernet router should use the IP address assigned to this connection as its default route. Can be Enabled or Disabled. See Configuring IP Routes for an explanation of default routes.
- Use Dhcp:
When set to Enable, the device will acquire additional IP information from the ISP's DHCP server. The PPP connection itself acquires the device's IP address, mask, DNS address, and default gateway address. With Use DHCP enabled, the device will acquire IP addresses for various other server types (WINS, SMTP, POP3, etc. -- these server types are listed on the DHCP Server Configuration page).
- Use DNS:
When set to Enable, the DNS address learned through the PPP connection will be distributed to clients of the device's DHCP server. This option is useful only when the ADSL/Ethernet Router is configured to act as a DHCP server for your LAN. When set to Disable, LAN hosts will use the DNS address(es) pre-configured in the DHCP pool (see Configuring DHCP Server) and in the DNS feature (see Configuring DNS).
- Oper. Status:
Indicates whether the link is currently up or down or if a specific type of data exchange is under way (e.g., password authorization or DHCP).
- Action(s):
Provides icons you can click on to modify (), delete (), or view additional details on () the PPP interface.
Not all settings are available on the PPP Interface - Modify page. To modify the other settings, you must delete the interface and create a new one. Be sure to submit and commit your changes if you make modifications.
Viewing PPP Interface Details
You can click in the PPP Configuration table to view additional details on the interface setup. The PPP Interface - Detail page displays the following additional fields (duplicated fields are not restated, see above):
- Status:
Indicates which of the following interface statuses has been manually selected:
- Start: The connection will be established for use whenever the device is turned on or rebooted.
- Stop: The PPP interface has been manually disabled and cannot currently be used. It can only be used after being manually returned to the Start state.
- Start On Data: The PPP connection will be established automatically whenever data is sent to the interface (e.g., when a LAN user attempts to use the Internet), and will time-out whenever the interface is idle for a specified amount of time.
- Service Name:
(This feature is available with PPPoE interfaces but not with PPPoA interfaces.) The name of the ISP service you are using with this PPP connection. ISPs may offer different types of services (for example, for online gaming or business services), each requiring a different login and other connection properties.
- Last Fail Cause:
Indicates the action that ended the previous PPP session:
- No Valid PADO Recvd: The unit initiated a PPoE handshake but did not receive a packet in reply from the ISP.
- No Valid PADS Recvd: After the initial handshake, the unit did not receive a confirmation packet from the ISP.
- Stopped by User: The user stopped the connection (for example, by changing the Configuration Manager settings for the PPP interface.)
- No Activity: The PPP communication timed out, in accordance with the timeout period specified on the PPP Configuration page.
- Auth Failure: The ISP could not authorize the connection based on the user name and/or password provided.
- PADT recvd: The ISP issued a special packet type to terminate the PPP connection.
- VC down: The Virtual Circuit between the unit and the ISP is down.
- Internal failure: A system software failure occurred.
- DNS:
The IP address of the DNS server (located with your ISP) used on this PPP connection.
- SDNS:
The IP address of the secondary DNS server (located with your ISP) used on this PPP connection.
- Security Protocol:
The type of PPP security to be used on this connection. Can be PAP (Password Authentication Protocol) or CHAP (Challenge Handshake Authentication Protocol).
- Login Name:
The name you use to log in to your ISP each time this PPP connection is established.
Adding a PPP Interface
If you intend to use more than one type of service from your ISP, you can configure multiple PPP interfaces, each with unique logon and other properties. |