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Example: Concurrent Configuration of Dynamic DHCP IP Demux and PPPoE Demux Interfaces over the Same VLAN Demux Interface

 

This example shows how to configure both dynamic DHCP IP demux and PPPoE demux interfaces over the same dynamic VLAN demux interface. The example provides an IPv4 configuration. However, you can also configure concurrent IP over Ethernet/DHCP and PPPoE interfaces over the same VLAN interface using IPv6 addressing.

Requirements

Before you begin, make sure to configure either DHCP Relay or DHCP Local Server. For information about configuring either of these components, see Extended DHCP Relay Agent Overview or Understanding Differences Between Legacy DHCP and Extended DHCP.

Overview

With the introduction of the family pppoe statement, PPPoE is no longer treated as an exclusive encapsulation configuration and you can configure VLAN interfaces with multiple protocol interface stacks. For example, you can configure IP over Ethernet/DHCP and PPPoE interfaces concurrently over a single VLAN interface.

Configuration

Preparing a Subscriber Access Interface

CLI Quick Configuration

To quickly configure the aggregated Ethernet interface over which subscribers access the router:

Step-by-Step Procedure

When configuring multiple protocol interface stacks concurrently over the same VLAN interface, you must configure physical interfaces over which DHCP or PPPoE clients initially access the router. We recommend that you specify the same VLAN tagging for the interface that you expect from incoming clients. This example uses flexible VLAN tagging to simultaneously support transmission of 802.1Q VLAN single-tag and dual-tag frames on logical interfaces on the same Ethernet port.

To automatically create dynamic VLANs, the interface must also include the VLAN range type (single or stacked), dynamic profile reference, and any specific ranges you want the VLANs to use.

To configure a physical interface for subscriber access:

  1. Access the physical interface over which you want subscribers to initially access the router.
  2. Specify the aggregated Ethernet interface to which the physical interface belongs.
  3. Repeat Step 1 and Step 2for each interface you want to assign to the aggregated Ethernet bundle.
  4. Access the aggregated Ethernet interface.
  5. Specify the VLAN tagging that you want the aggregated Ethernet interfaces to use.
  6. Edit the auto-configure stanza to automatically configure VLANs.
  7. Edit the vlan-ranges stanza for single-tagged VLANs.
  8. Specify the dynamic VLAN profile that you want the interface to use for dynamically creating single-tagged VLANs.
  9. Specify what VLAN Ethernet packet type the VLAN profile accepts.
  10. Specify the VLAN ranges that you want the dynamic profile to use. The following example specifies a lower VLAN ID limit of 1000 and an upper VLAN ID limit of 1500.
  11. Edit the stacked-vlan-ranges stanza for the dual-tagged VLANs.
  12. Specify the dynamic VLAN profile that you want the interface to use for dynamically creating dual-tagged VLANs.
  13. Specify what VLAN Ethernet packet type the stacked VLAN profile accepts.
  14. Specify the outer and inner stacked VLAN ranges that you want the dynamic profile to use. The following example specifies an outer stacked VLAN ID range from 1501 through 2000 (to avoid overlapping VLAN IDs with single-tag VLANs) and an inner stacked VLAN ID range of any (enabling a range from 1 through 4094 for the inner stacked VLAN ID).
  15. (Optional) Activate the transmission of LACP packets on the aggregated Ethernet interfaces.
  16. Specify that the aggregated Ethernet interfaces use link protection.

Preparing the Loopback Interface

CLI Quick Configuration

To quickly configure the required loopback interface for this example:

Step-by-Step Procedure

You must configure a loopback interface for use as the unnumbered address and preferred source address for dynamically created interfaces.

To configure the required loopback interface for this example:

  1. Configure a loopback interface.
  2. Specify that the loopback interface accept inet packets.
  3. Specify the IP address for the loopback interface.

Configuring a Dynamic Profile to Create Dynamic Single-Tagged VLANs

CLI Quick Configuration

To quickly configure the dynamic profile used to dynamically create single-tagged VLANs in the example:

Step-by-Step Procedure

For both dynamic DHCP IP demux and dynamic PPPoE interfaces to reside concurrently on a single-tagged VLAN interface, the VLAN interface must first exist.

To configure a dynamic profile that automatically creates VLAN interfaces:

  1. Create a dynamic profile for automatically creating VLAN interfaces.
  2. Specify that the dynamic VLAN profile use the demux interface.
  3. Specify that the dynamic profile apply the demux interface unit value to the dynamic VLANs.
  4. Specify that the demux source accept IPv4 (inet) packets.
  5. (Optional) Specify that each dynamically created interface respond to any ARP request, as long as an active route exists to the target address of the ARP request.
  6. Specify that VLAN IDs are dynamically created.
  7. Specify the logical underlying interface for the dynamic VLANs.
  8. Specify that the VLAN demux interface can accept inet family packets for IP over Ethernet/DHCP subscribers.
  9. Specify the loopback address as the unnumbered address and preferred source address for the inet family.
  10. Specify that the VLAN demux interface can accept pppoe family packets for PPPoE subscribers.
  11. Prevent multiple PPPoE sessions from being created for the same PPPoE subscriber on the same VLAN interface.
  12. Apply the dynamic PPP interface profile to any dynamic PPP interfaces.

Configuring a Dynamic Profile to Create Dynamic Dual-Tagged VLANs

CLI Quick Configuration

To quickly configure the dynamic profile used to dynamically create stacked/dual-tagged VLANs in the example:

Step-by-Step Procedure

For both dynamic DHCP IP demux and dynamic PPPoE interfaces to reside concurrently on a VLAN interface, the VLAN interface must first exist.

To configure a dynamic profile that automatically creates stacked/dual-tagged VLAN interfaces:

  1. Create a dynamic profile for automatically creating VLAN interfaces.
  2. Specify that the dynamic VLAN profile use the demux interface.
  3. Specify that the dynamic profile apply the demux interface unit value to the dynamic VLANs.
  4. Specify that the demux source accept IPv4 (inet) packets.
  5. (Optional) Specify that each dynamically created interface respond to any ARP request, as long as an active route exists to the target address of the ARP request.
  6. Specify that the outer VLAN ID is dynamically created.
  7. Specify that the inner VLAN ID is dynamically created.
  8. Specify the logical underlying interface for the dynamic VLANs.
  9. Specify that the VLAN demux interface can accept inet family packets for IP over Ethernet/DHCP subscribers.
  10. Specify the loopback address as the unnumbered address and preferred source address for the inet family.
  11. Specify that the VLAN demux interface can accept pppoe family packets for PPPoE subscribers.
  12. Prevent the activation of another dynamic PPPoE logical interface on the same demux underlying interface.
  13. Apply the dynamic PPP interface profile to any dynamic PPP interfaces.

Configuring a Dynamic Profile to Create Dynamic IP Demux Interfaces

CLI Quick Configuration

To quickly configure the dynamic profile used to dynamically create DHCP IP demux interfaces in the example:

Step-by-Step Procedure

To configure a dynamic profile that automatically creates IP demux interfaces:

  1. Create a dynamic profile for dynamically creating IP demux interfaces.
  2. Specify that the dynamic profile use the demux0 interface.
  3. Specify that the dynamic profile apply the interface unit value to the dynamic PPPoE interfaces.
  4. (Optional) Configure the router to respond to any ARP request, as long as the router has an active route to the target address of the ARP request.
  5. Specify the logical underlying interface for the dynamic IP demux interfaces.
  6. Specify the protocol family information for the dynamic IP demux interfaces.
  7. Specify the demux source address is obtained from the incoming subscriber IP address.
  8. Specify the loopback interface as the unnumbered address and the demux interface IP address as the preferred source address for the dynamic IP demux interfaces.

Configuring a Dynamic Profile to Create Dynamic PPPoE Interfaces

CLI Quick Configuration

To quickly configure the dynamic profile used to dynamically create PPPoE interfaces in the example:

Step-by-Step Procedure

  1. Create a dynamic profile for automatically creating PPPoE interfaces.
  2. Specify that the dynamic PPPoE profile use the pp0 interface.
  3. Specify that the dynamic profile apply the interface unit value to the dynamic PPPoE interfaces.
  4. Specify that dynamically created PPPoE interfaces use PAP authentication.
  5. Specify the logical underlying interface for the dynamic PPPoE interfaces.
  6. Specify that the router act as a PPPoE server.
  7. (Optional) Disable the sending of keepalive messages on the dynamic PPPoE interfaces.
  8. Specify the protocol family information for the dynamic PPPoE interfaces.
  9. Specify the loopback interface as the unnumbered address for the dynamic PPPoE interfaces.

Verification

Subscriber Verification

Purpose

View subscriber information on the router.

Action

  • To display dynamic subscriber information:

Interface Verification

Purpose

View interface-specific information on the router.

Action

  • To display interface-specific output: