# Configuring PPPoE for Ethernet Modules

You can configure PPPoE on Fast Ethernet (FE), Gigabit Ethernet (GE), and 10-Gigabit Ethernet (10GE) modules. You can configure Ethernet interfaces with IP only, with PPPoE only, with both IP and PPPoE, and with or without VLANs.

This section provides information about configuring PPPoE without VLANs. If you want to configure PPPoE with VLANs, see Configuring VLAN and S-VLAN Subinterfaces , which shows common VLAN configurations such as:

- PPPoE over VLAN
- IP over VLAN and PPPoE over VLAN

  | Note: Configuring VLAN and S-VLAN Subinterfaces provides other non-VLAN configuration examples, such as configurations using MPLS.

For more information about specific Ethernet modules and the protocols and applications they support, see:

- ERX Module Guide, Appendix A, Module Protocol Support (for ERX7xx models, ERX14xx models, and ERX310 router)
- E120 and E320 Module Guide, Appendix A, IOA Protocol Support (for E120 and E320 routers)

## PPPoE Interface and Subinterface Limits

PPPoE subinterfaces can be distributed in any way across I/O module ports. For example, you can configure the maximum supported number of PPPoE subinterfaces on one port of an FE-2 I/O module and no PPPoE subinterfaces on the other port.

For information about current system maximums supported for PPPoE interfaces and subinterfaces, see JunosE Release Notes, Appendix A, System Maximums.

## Configuring IPv4 and IPv6 over PPPoE with VLAN

You can configure IPv4 and IPv6 interface columns over static PPPoE, as shown in Figure 41.

Figure 41: Example of Configuring IPv4 and IPv6 over PPPoE

To configure IPv4 and IPv6 interface columns over static PPPoE:

1. Specify a Fast Ethernet, Gigabit Ethernet, or 10-Gigabit Ethernet interface.
   host1(config)#interface gigabitEthernet 2/0/1
2. Specify VLAN as the encapsulation method.
   host1(config-if)#encapsulation vlan

   The VLAN major interface is added.

3. Create a VLAN subinterface by adding a subinterface number to the interface identification command.
   host1(config-if)#interface gigabitEthernet 2/0/1.1
4. Assign a VLAN ID for the subinterface.
   host1(config-if)#vlan id 1
5. Create a PPPoE subinterface.
   host1(config-if)#pppoe
6. Specify PPPoE as the encapsulation method on the interface.
   host1(config-if)#pppoe subinterface gigabitEthernet 2/0/1.1.1 host1(config-if)#encapsulation ppp
7. Specify the order of preference for the primary authentication protocol.
   host1(config-if)#ppp authentication pap chap eap
8. Enable IPv6 processing on an interface without assigning an explicit IPv6 address to that interface.
   host1(config-if)#ipv6 unnumbered loopback 0
9. Enable the IPv6 Neighbor Discovery process on an interface.
   host1(config-if)#ipv6 nd
10. Specify which IPv6 prefixes the system includes in IPv6 router advertisements.
    host1(config-if)#ipv6 nd prefix-advertisement 2002:1::/64 60000 45000 onlink autoconfig
11. (Optional) Configure additional VLAN subinterfaces by completing Steps 3 through 10.

encapsulation ppp

- Use to specify PPP as the encapsulation method for the interface.
- Example
  host1(config-if)#encapsulation ppp
- Use the no version to disable PPP on an interface.
- See encapsulation ppp.

encapsulation vlan

- Use to configure VLAN as the encapsulation method for the interface.
- Example
  host1(config-if)#encapsulation vlan
- Use the no version to disable VLAN on an interface.
- See encapsulation vlan.

ipv6 address

- Use to add an IPv6 address to an interface or a subinterface.
- Example
  host1(config)#interface gigabitEthernet 1/0.25 host1(config-if)#ipv6 address 1::1/64
- Use the no version to remove an IPv6 address.
- See ipv6 address

ipv6 nd

- Use to enable the IPv6 Neighbor Discovery process on an interface.
- You can include the following commands in IPv6 profiles to configure Neighbor Discovery route advertisement characteristics.

  Command | Description
  --- | ---
  ipv6 nd | Enables Neighbor Discovery on an interface
  ipv6 nd prefix-advertisement | Specifies IPv6 prefix included in IPv6 router advertisements

- Example
  host1(config)#profile ProfileIpv6South22 host1(config-profile)#ipv6 nd
- Use the no version to disable the Neighbor Discovery process for the profile.
- See ipv6 nd

ipv6 unnumbered

- Use to set up an unnumbered interface.
- An unnumbered interface does not have an IPv6 address assigned to it. Unnumbered interfaces are often used in point-to-point connections where an IPv6 address is not required.
- This command enables IPv6 processing on an interface without your having to assign an explicit IPv6 address to the interface.
- You supply an interface location that is the type and number of another interface on which the router has an assigned IPv6 address. This interface cannot be another unnumbered interface.
- Example
  host1(config-if)#ipv6 unnumbered loopback 0
- Use the no version to disable IPv6 processing on an interface.
- See ipv6 unnumbered

ppp authentication

- Use to request authentication from a PPP peer and set the authentication method.
- The router supports the MD5 authentication algorithm for CHAP authentication.
- Example 1—Specifies the order of preference for the primary authentication protocol
  host1(config-if)#ppp authentication pap chap eap

  The router requests the use of PAP as the authentication protocol (because it appears first in the command line). If the peer refuses to use PAP, the router requests the CHAP protocol. If the peer refuses to use CHAP, the router requests the EAP protocol. If the peer refuses to negotiate authentication, the router terminates the PPP session.

- Example 2—Configures EAP or CHAP or PAP on a dynamic PPP interface
  host1(config)#profile ppptest host1(config-profile)#ppp authentication eap chap pap

  In this example, the router first attempts EAP negotiation. If PPP receives a NAK from the peer in response to the EAP request, then the router attempts CHAP negotiation. If PPP receives a NAK from the peer in response to the CHAP request, then the router attempts PAP negotiation. If PAP is also rejected, then PPP terminates the session.

- Use the no version to specify that the router does not require authentication.
- See ppp authentication.

pppoe

- Use to specify PPPoE as the encapsulation method for the interface.
- This command creates a PPPoE major interface.
- Example
  host1(config-if)#pppoe
- Use the no version to remove the PPPoE major interface.
- See pppoe.

vlan id

- Use to specify the VLAN ID.
- Use a VLAN ID that is in the range 0–4095 and is unique within the Ethernet interface.
- Examples
  host1(config-if)#vlan id 400 host1(config-if)#vlan id 4 255 mac-address 0090.1a01.1234
- There is no no version.
- See vlan id.

## Configuring PPPoE Without VLANs

To configure PPPoE over an Ethernet interface without VLANs:

1. Specify a Fast Ethernet, Gigabit Ethernet, or 10-Gigabit Ethernet interface.
   host1(config)#interface fastEthernet 4/1
2. Specify PPPoE as the encapsulation method on the interface.
   host1(config-if)#pppoe
3. Create a PPPoE subinterface.
   host1(config-if)#pppoe subinterface fastEthernet 4/1.1
4. Specify PPP as the encapsulation method on the interface.
   host1(config-subif)#encapsulation ppp
5. (Optional) Configure an access concentrator (AC) name on the PPPoE interface.
   host1(config-subif)#pppoe acname CYM9876
6. (Optional) Set up the router to prevent a client from establishing more than one session using the same MAC address.

   When the duplicate protection feature is enabled, multiple IWF PPPoE sessions (sent from PPPoE clients to the PPPoE access concentrator) that contain the same MAC address are still processed and can access network services until the maximum number of PPPoE sessions configured per major interface (configured using the pppoe sessions command) is reached.

   host1(config-subif)#pppoe duplicate-protection
7. Assign an IP address and mask.
   host1(config-if)#ip address 192.6.129.5 255.255.255.0
8. (Optional) Configure additional PPPoE subinterfaces by completing Steps 3 through 7 using unique numbering.

Figure 42 illustrates the interface stack for this configuration.

Figure 42: Example of PPPoE Stacking

encapsulation ppp

- Use to specify PPP as the encapsulation method for the interface.
- Example
  host1(config-if)#encapsulation ppp
- Use the no version to disable PPP on an interface.
- See encapsulation ppp.

interface fastEthernet

- Use to select a Fast Ethernet interface.
- For more information, see Configuring Ethernet Interfaces in JunosE Physical Layer Configuration Guide.
- Example
  host1(config)#interface fastEthernet 1/0
- Use the no version to remove IP from an interface or subinterface. You must issue the no version from the highest level down; you cannot remove an interface or subinterface if the one above it still exists.
- See interface fastEthernet.

interface gigabitEthernet

interface tenGigabitEthernet

- Use to select a Gigabit Ethernet interface or a 10-Gigabit Ethernet interface.
- To specify a Gigabit Ethernet interface for ERX7xx models, ERX14xx models, and ERX310 router, use the slot/port[.subinterface ] format.
- To specify a Gigabit Ethernet interface or 10-Gigabit Ethernet interface for E120 and E320 routers, use the slot/adapter/port[.subinterface ] format.
- For more information, see Configuring Ethernet Interfaces in JunosE Physical Layer Configuration Guide.
- Examples
  host1(config)#interface gigabitEthernet 1/0 host1(config)#interface gigabitEthernet 4/0/1 6.0.0FRS host1(config)#interface tenGigabitEthernet 4/0/1
- Use the no version to remove IP from an interface. You must issue the no version from the highest level down; you cannot remove an interface or subinterface if the one above it still exists.
- See interface gigabitEthernet.
- See interface tenGigabitEthernet.

ip address

- Use to assign an IP address and subnet mask to an interface or subinterface.
- Example
  host1(config-if)#ip address 192.1.1.1 255.255.255.0
- Use the no version to remove an IP address or disable IP processing.
- See ip address.

pppoe

- Use to specify PPPoE as the encapsulation method for the interface.
- This command creates a PPPoE major interface.
- Example
  host1(config-if)#pppoe
- Use the no version to remove the PPPoE major interface.
- See pppoe.

pppoe acName

- Use to configure an access concentrator (AC) name on the PPPoE interface. When the AC (the server) receives a PPPoE Active Discovery Initiation (PADI) packet that it can serve, it replies by sending a PPPoE Active Discovery Offer (PADO) packet. The PADO packet contains the AC name configured using this command.
- If the AC name is not configured, the router name is used.
- The AC name can be a maximum of 64 characters.
- Example
  host1(config-subif)#pppoe acName CYM9876
- Use theno version to remove the AC name.
- See pppoe acName.

pppoe duplicate-protection

- Use to prevent a client from establishing more than one session using the same MAC address.
- This feature is disabled by default.
- For PPPoE sessions that contain the IWF-Session DSL Forum VSA (26-254) in the PADR packets sent from the client to the PPPoE access concentrator, multiple subscriber sessions with the same MAC address can originate. This behavior occurs because the interworking functionality (IWF) causes a PPPoE over ATM or PPP over ATM (PPPoA) session to be converted by the digital subscriber line access multiplexer (DSLAM) into a PPPoE session. As a result of this conversion, the MAC addresses of all IWF PPPoE sessions contain the MAC address of the DSLAM device.

  For PPPoE sessions with the IWF-Session VSA, duplication of MAC addresses is configured by default. Regardless of whether the duplicate protection feature is enabled, multiple IWF PPPoE sessions with the same MAC address (the address of the DSLAM device) are not terminated until the limit on the maximum number of PPPoE sessions configured on the major interface is reached.

  See Guidelines for Configuring Duplicate Protection for IWF PPPoE Sessions for a list of considerations to be observed when you use the duplicate protection feature for IWF PPPoE sessions.

- Example
  host1(config-subif)#pppoe duplicate-protection
- Use the no version to disable duplicate protection.
- See pppoe duplicate-protection.

pppoe subinterface fastEthernet

- Use to create a PPPoE subinterface on a Fast Ethernet module.
- On ERX7xx models, ERX14xx models, and the ERX310 router, use the slot/port/pppoeSubinterface format.
- Example
  host1(config)#pppoe subinterface fastEthernet 4/1.1
- Use the no version to remove the PPPoE subinterface.
- See pppoe subinterface.