Example: Configuring a Dual Stack That Uses NDRA and DHCPv6 Prefix Delegation over PPPoE
Requirements
This example uses the following hardware and software components:
- MX Series 3D Universal Edge Router
- Junos OS Release 11.4 or later
Overview
This design uses NDRA and DHCPv6 prefix delegation in your subscriber access network as follows:
- The access network is PPPoE.
- NDRA is used to assign a global IPv6 address on the WAN link. The prefixes used in router advertisements come from a local pool that is specified using AAA RADIUS.
- DHCPv6 prefix delegation is used for subscriber LAN addressing. It uses a delegated prefix from a local pool that is specified using AAA RADIUS.
- DHCPv4 is used for subscriber LAN addressing.
- DHCPv6 subscriber sessions are layered over an underlying PPPoE subscriber session.
Topology
Figure 1: PPPoE Subscriber Access Network with NDRA and DHCPv6 Prefix Delegation

Table 1 describes the configuration components used in this example.
Table 1: Configuration Components Used in Dual Stack with NDRA and DHCPv6 Prefix Delegation
Configuration Component | Component Name | Purpose |
---|---|---|
Dynamic profiles | DS-dyn-ipv4v6-ndra | Profile that creates a PPPoE logical interface when the subscriber logs in. |
Interfaces | ge-3/3/0 | Underlying Ethernet interface. |
lo0 | Loopback interface for use in the access network. The loopback interface is automatically used for unnumbered interfaces. | |
Address-assignment pools | default-ipv4-pool-2 | Pool that provides IPv4 addresses for the subscriber LAN. |
ndra-2010 | Pool that provides IPv6 prefixes used in router advertisements. These prefixes are used to create a global IPv6 address that is assigned to the CPE WAN link. | |
dhcpv6-pd-pool | Pool that provides a pool of prefixes that are delegated to the CPE and are used for assigning IPv6 global addresses on the subscriber LAN. |
Configuration
- Configuring a DHCPv6 Local Server for DHCPv6 over PPPoE
- Configuring a Dynamic Profile for the PPPoE Logical Interface
- Configuring a Loopback Interface
- Configuring a Static Underlying Ethernet Interface for Dynamic PPPoE Subscriber Interfaces
- Specifying the BNG IP Address
- Configuring RADIUS Server Access
- Configuring RADIUS Server Access Profile
- Configuring Local Address-Assignment Pools
- Specifying the Address-Assignment Pool to Be Used for DHCPv6 Prefix Delegation
CLI Quick Configuration
The following is the complete configuration for this example:
Configuring a DHCPv6 Local Server for DHCPv6 over PPPoE
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To layer DHCPv6 above the PPPoE IPv6 family (inet6), associate DHCPv6 with the PPPoE interfaces by adding the PPPoE interfaces to the DHCPv6 local server configuration. Because this example uses a dynamic PPPoE interface, we are using the pp0.0 (PPPoE) logical interface as a wildcard to indicate that a DHCPv6 binding can be made on top of a PPPoE interface.
To configure a DHCPv6 local server:
- Access the DHCPv6 local server configuration.[edit]user@host# edit system services dhcp-local-server dhcpv6
- Create a group for dynamic PPPoE interfaces and assign
a name.
The group feature groups a set of interfaces and then applies a common DHCP configuration to the named interface group.
[edit system services dhcp-local-server dhcpv6]user@host# edit group DHCPv6-over-pppoe - Add an interface for dynamic PPPoE logical interfaces. [edit system services dhcp-local-server dhcpv6 group DHCPv6-over-pppoe]user@host# set interface pp0.0
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring a Dynamic Profile for the PPPoE Logical Interface
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
Create a dynamic profile for the PPPoE logical interface. This dynamic profile supports both IPv4 and IPv6 sessions on the same logical interface.
To configure the dynamic profile:
- Create and name the dynamic profile.[edit]user@host# edit dynamic-profiles DS-dyn-ipv4v6-ra
- Configure a PPPoE logical interface (pp0) that is used
to create logical PPPoE interfaces for the IPv4 and IPv6 subscribers. [edit dynamic-profiles DS-dyn-ipv4v6-ra]user@host# edit interfaces pp0
- Specify $junos-interface-unit as the predefined
variable to represent the logical unit number for the pp0 interface. The variable is dynamically replaced with the actual
unit number supplied by the network when the subscriber logs in.[edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0]user@host# edit unit $junos-interface-unit
- Specify $junos-underlying-interface as the predefined
variable to represent the name of the underlying Ethernet interface
on which the router creates the dynamic PPPoE logical interface. The
variable is dynamically replaced with the actual name of the underlying
interface supplied by the network when the subscriber logs in.[edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set pppoe-options underlying-interface $junos-underlying-interface
- Configure the router to act as a PPPoE server when a PPPoE
logical interface is dynamically created.[edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set pppoe-options server
- Configure the IPv4 family for the pp0 interface. Specify
the unnumbered address to dynamically create loopback interfaces. [edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set family inet unnumbered-address lo0.0
- Configure the IPv6 family for the pp0 interface. Because
the example uses router advertisement, assign the predefined variable $junos-ipv6-address. [edit dynamic-profilesDS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set family inet6 unnumbered-address $junos-ipv6-address
- Configure one or more PPP authentication protocols for
the pp0 interface.[edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set ppp-options chap user@host# set ppp-options pap
- Enable keepalives and set an interval for keepalives.
We recommend an interval of 30 seconds.[edit dynamic-profiles DS-dyn-ipv4v6-ra interfaces pp0 unit "$junos-interface-unit"]user@host# set keepalives interval 30
- Access the router advertisement configuration.[edit dynamic-profiles DS-dyn-ipv4v6-ra]user@host# edit protocols router-advertisement
- Specify the interface on which the NDRA configuration
is applied. [edit dynamic-profiles DS-dyn-ipv4v6-ra protocols router-advertisement]user@host# edit interface $junos-interface-name
- Specify a prefix value contained in router advertisement
messages sent to the CPE on interfaces created with this dynamic profile.
If you specify the $junos-ipv6-ndra-prefix predefined variable, the
actual value is obtained from a local pool or through AAA.[edit dynamic-profiles DS-dyn-ipv4v6-ra protocols router-advertisement interface "$junos-interface-name"]user@host# set prefix $junos-ipv6-ndra-prefix
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring a Loopback Interface
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To configure a loopback interface:
- Create the loopback interface and specify a unit number. [edit]user@host# edit interfaces lo0 unit 0
- Configure the interface for IPv4.[edit interfaces lo0 unit 0]user@host# set family inet address 77.1.1.1/32 primary
- Configure the interface for IPv6.[edit interfaces lo0 unit 0]user@host# set family inet6 address 2030:0:0:0::1/64 primary
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring a Static Underlying Ethernet Interface for Dynamic PPPoE Subscriber Interfaces
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To configure the underlying Ethernet interface:
- Specify the name and logical unit number of the static
underlying Ethernet interface to which you want to attach the IPv4
and IPv6 dynamic profile.[edit]user@host# edit interfaces ge-3/3/0 unit 1109
- Configure a description for the interface. [edit interfaces ge-3/3/0 unit 1109]user@host# set description "dynamic ipv4v6 dual stack, ndra, dhcpv6 pd”
- Configure PPPoE encapsulation on the underlying interface.[edit interfaces ge-3/3/0 unit 1109]user@host# set encapsulation ppp-over-ether
- Configure the VLAN ID.[edit interfaces ge-3/3/0 unit 1109]user@host# set vlan-id 1109
- Attach the dynamic profile to the underlying interface.[edit interfaces ge-3/3/0 unit 1109]user@host# set pppoe-underlying-options dynamic-profile DS-dyn-ipv4v6-ra
- (Optional) Prevent multiple PPPoE sessions from being
created for the same PPPoE subscriber on the same VLAN interface.[edit interfaces ge-3/3/0 unit 1109]user@host# set pppoe-underlying-options duplicate-protection
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Specifying the BNG IP Address
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
![]() | Best Practice: We strongly recommend that you configure the BNG IP address to avoid unpredictable behavior if the interface address on a loopback interface changes. |
Step-by-Step Procedure
To configure the IP address of the BNG:
- Access the routing-options configuration. [edit]user@host# edit routing-options
- Specify the IP address or the BNG. [edit routing-options]user@host# set router-id 10.0.0.0
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring RADIUS Server Access
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To configure RADIUS servers:
- Create a RADIUS server configuration, and specify the
address of the server. [edit]user@host# edit access radius-server 10.9.0.9
- Configure the required secret (password) for the server.
Secrets enclosed in quotation marks can contain spaces. [edit access radius-server 10.9.0.9]user@host# set secret "$9$lXRv87GUHm5FYgF/CA1I"
- Configure the source address that the BNG uses when it
sends RADIUS requests to the RADIUS server. [edit access radius-server 10.9.0.9]user@host# set source address 10.0.0.1
- (Optional) Configure the number of times that the router
attempts to contact a RADIUS accounting server. You can configure
the router to retry from 1 through 16 times. The default setting is
3 retry attempts.[edit access radius-server 10.9.0.9]user@host# set retry 4
- (Optional) Configure the length of time that the local
router or switch waits to receive a response from a RADIUS server.
By default, the router or switch waits 3 seconds. You can configure
the timeout to be from 1 through 90 seconds.[edit access radius-server 10.9.0.9]user@host# set timeout 45
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring RADIUS Server Access Profile
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To configure a RADIUS server access profile:
- Create a RADIUS server access profile. [edit]user@host# edit access profile Access-Profile
- Specify the order in which authentication methods are
used. [edit access profile Access-Profile]user@host# set authentication-order radius
- Specify the address of the RADIUS server used for authentication
and the server used for accounting. [edit access profile Access-Profile]user@host# set radius authentication-server 10.9.0.9user@host# set radius accounting-server 10.9.0.9
- Configure RADIUS accounting values for the access profile. [edit access profile Access-Profile]user@host# set accounting order [ radius none ]user@host# set accounting update-interval 120user@host# set accounting statistics volume-time
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Configuring Local Address-Assignment Pools
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
Configure three address-assignment pools for DHCPv4, DHCPv6 prefix delegation, and NDRA.
To configure the address-assignment pools:
- Configure the address-assignment pool for DHCPv4.[edit]user@host# edit access address-assignment pool default-ipv4-pool-2user@host# edit family inetuser@host# set network 10.10.0.0/16user@host# set range r5 low 10.10.0.1user@host# set range r5 high 10.10.250.250
- Configure the address-assignment pool for DHCPv6 prefix
delegation.[edit]user@host# edit access address-assignment pool dhcpv6-pd-pooluser@host# edit family inet6user@host# set prefix 2040:2000:2000::/48user@host# set range r1 prefix-length 64
- Configure the address-assignment pool for NDRA.[edit]user@host# edit access address-assignment pool ndra-2010user@host# edit family inet6user@host# set prefix 2010:0:0:0::/48user@host# set range L prefix-length 64
- (Optional) Enable duplicate prefix protection. [edit access]user@host# set address-protection
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Specifying the Address-Assignment Pool to Be Used for DHCPv6 Prefix Delegation
CLI Quick Configuration
To quickly configure this example, copy the following commands, paste them into a text file, remove any line breaks, change any details necessary to match your network configuration, and then copy and paste the commands into the CLI at the [edit] hierarchy level.
Step-by-Step Procedure
To specify that the dhcp-pd-pool is used for DHCPv6 prefix delegation:
- Access the DHCPv6 local server configuration. [edit]user@host# edit system services dhcp-local-server dhcpv6
- Specify the address pool that assigns the delegated prefix.[edit system services dhcp-local-server dhcpv6]user@host# set overrides delegated-pool dhcpv6-pd-pool
Results
From configuration mode, confirm your configuration by entering the show command.
If you are done configuring the device, enter commit from configuration mode.
Verification
Confirm that the configuration is working properly.
- Verifying Active Subscriber Sessions
- Verifying Both IPv4 and IPv6 Address in Correct Routing Instance
- Verifying Dynamic Subscriber Sessions
- Verifying DHCPv6 Address Pools Used for NDRA and DHCPv6 Prefix Delegation
- Verifying DHCPv6 Address Bindings
- Verifying Router Advertisements
- Verifying the Status of the PPPoE Logical Interface
Verifying Active Subscriber Sessions
Purpose
Verify active subscriber sessions.
Action
From operational mode, enter the show subscribers summary command.
user@host>show subscribers summary
Subscribers by State Active: 2 Total: 2 Subscribers by Client Type DHCP: 1 PPPoE: 1 Total: 2
Meaning
The fields under Subscribers by State show the number of active subscribers.
The fields under Subscribers by Client Type show the number of active DHCP and DHCPoE subscriber sessions.
Verifying Both IPv4 and IPv6 Address in Correct Routing Instance
Purpose
Verify that the subscriber has both an IPv4 and IPv6 address and is placed in the correct routing instance.
Action
From operational mode, enter the show subscribers command.
user@host>show subscribers
Interface IP Address/VLAN ID User Name LS:RI pp0.1073741864 2.2.0.5 dual-stack-v4v6-pd default:default * 2010:0:0:8::/64 pp0.1073741864 2040:2000:2000:5::/64 default:default
Meaning
The Interface field shows that there are two subscriber sessions running on the same interface. The IP Address field shows that one session is assigned an IPv4 address, and one session is assigned on IPv6 address.
The LS:RI field shows that the subscriber is placed in the correct routing instance and that traffic can be sent and received.
Verifying Dynamic Subscriber Sessions
Purpose
Verify dynamic PPPoE and DHCPv6 subscriber sessions. In this sample configuration, the DHCPv6 subscriber session should be layered over the underlying PPPoE subscriber session.
Action
From operational mode, enter the show subscribers detail command.
user@host>show subscribers detail
Type: PPPoE User Name: dual-stack-v4v6-pd IP Address: 2.2.0.5 IP Netmask: 255.255.0.0 IPv6 User Prefix: 2010:0:0:8::/64 Logical System: default Routing Instance: default Interface: pp0.1073741864 Interface type: Dynamic Dynamic Profile Name: DS-dyn-ipv4v6-ra MAC Address: 00:07:64:11:07:02 State: Active Radius Accounting ID: 87 Session ID: 87 Login Time: 2012-01-17 14:45:30 PST Type: DHCP IPv6 Prefix: 2040:2000:2000:5::/64 Logical System: default Routing Instance: default Interface: pp0.1073741864 Interface type: Static MAC Address: 00:07:64:11:07:02 State: Active Radius Accounting ID: 88 Session ID: 88 Underlying Session ID: 87 Login Time: 2012-01-17 14:46:00 PST DHCP Options: len 42 00 08 00 02 0b b8 00 01 00 0a 00 03 00 01 00 07 64 11 07 02 00 06 00 02 00 19 00 19 00 0c 00 00 00 00 00 00 00 00 00 00 00 00
Meaning
When a subscriber has logged in and started both an IPv4 and an IPv6 session, the output shows the active underlying PPPoE session and the active DHCPv6 session.
The Session ID field for the PPPoE session is 87. The Underlying Session ID for the DHCP session is 87, which shows that the PPPoE session is the underlying session.
Verifying DHCPv6 Address Pools Used for NDRA and DHCPv6 Prefix Delegation
Purpose
Verify the pool used for NDRA, the delegated address pool used for DHCPv6 prefix delegation, and the length of the IPv6 prefixes that were delegated to the CPE.
Action
From operational mode, enter the show subscribers extensive command.
user@host>show subscribers extensive
Type: PPPoE User Name: dual-stack-v4v6-pd IP Address: 2.2.0.5 IP Netmask: 255.255.0.0 IPv6 User Prefix: 2010:0:0:8::/64 Logical System: default Routing Instance: default Interface: pp0.1073741864 Interface type: Dynamic Dynamic Profile Name: DS-dyn-ipv4v6-ra MAC Address: 00:07:64:11:07:02 State: Active Radius Accounting ID: 87 Session ID: 87 Login Time: 2012-01-17 14:45:30 PST IPv6 Delegated Address Pool: dhcpv6-pd-pool IPv6 Delegated Address Pool: ndra-2010 IPv6 Delegated Network Prefix Length: 48 IPv6 Interface Address: 2010:0:0:8::1/64 Type: DHCP IPv6 Prefix: 2040:2000:2000:5::/64 Logical System: default Routing Instance: default Interface: pp0.1073741864 Interface type: Static MAC Address: 00:07:64:11:07:02 State: Active Radius Accounting ID: 88 Session ID: 88 Underlying Session ID: 87 Login Time: 2012-01-17 14:46:00 PST DHCP Options: len 42 00 08 00 02 0b b8 00 01 00 0a 00 03 00 01 00 07 64 11 07 02 00 06 00 02 00 19 00 19 00 0c 00 00 00 00 00 00 00 00 00 00 00 00 IPv6 Delegated Address Pool: dhcpv6-pd-pool IPv6 Delegated Network Prefix Length: 64 IPv6 Delegated Network Prefix Length: 48
Meaning
Under the PPPoE session, the IPv6 Delegated Address Pool fields show the names of the pools used for DHCPv6 prefix delegation and for NDRA prefixes. The IPv6 Delegated Network Prefix Length field shows the length of the prefix used to assign the IPv6 address for this subscriber session. The IPv6 Interface Address field shows the IPv6 address assigned to the CPE interface from the NDRA pool.
Under the DHCP session, the IPv6 Delegated Address Pool field shows the name of the pool used for DHCPv6 prefix delegation. The IPv6 Delegated Network Prefix Length fields show the length of the prefix used in DHCPv6 prefix delegation.
Verifying DHCPv6 Address Bindings
Purpose
Display the address bindings in the client table on the DHCPv6 local server.
Action
From operational mode, enter the show dhcpv6 server binding command.
user@host>show dhcpv6 server binding
Prefix Session Id Expires State Interface Client DUID 2040:2000:2000:5::/64 88 86189 BOUND pp0.1073741864 LL0x1-00:07:64:11:07:02
If you have many active subscriber sessions, you can display the server binding for a specific interface.
user@host>show dhcpv6 server binding interface
pp0.1073741864
Prefix Session Id Expires State Interface Client DUID 2040:2000:2000:5::/64 88 86182 BOUND pp0.1073741864 LL0x1-00:07:64:11:07:02
Meaning
The Prefix field shows the DHCPv6 prefix assigned to the subscriber session from the pool used for DHCPv6 prefix delegation.
Verifying Router Advertisements
Purpose
Verify that router advertisements are being sent, and that router solicits are being received.
Action
From operational mode, enter the show ipv6 router-advertisement command.
user@host>show ipv6 router-advertisement
Interface: pp0.1073741864 Advertisements sent: 3, last sent 00:03:29 ago Solicits received: 0 Advertisements received: 0
If you have a large number of subscriber interfaces, you can display router advertisements for a specific interface.
user@host>show ipv6 router-advertisement interface
pp0.1073741864
Interface: pp0.1073741864 Advertisements sent: 3, last sent 00:03:34 ago Solicits received: 0 Advertisements received: 0
Meaning
The display shows the number of advertisements that the router sent, the number of solicits that the router received, and the number of advertisements that the router received.
Verifying the Status of the PPPoE Logical Interface
Purpose
Display status information about the PPPoE logical interface (pp0).
Action
From operational mode, enter the show interfaces pp0.logical command.
user@host>show interfaces pp0.1073741864
Logical interface pp0.1073741864 (Index 388) (SNMP ifIndex 681) Flags: Point-To-Point SNMP-Traps 0x4000 Encapsulation: PPPoE PPPoE: State: SessionUp, Session ID: 10, Session AC name: almach, Remote MAC address: 00:07:64:11:07:02, Underlying interface: ge-3/3/0.1109 (Index 367) Bandwidth: 1000mbps Input packets : 22 Output packets: 50 Keepalive settings: Interval 30 seconds, Up-count 1, Down-count 3 LCP state: Opened NCP state: inet: Opened, inet6: Opened, iso: Not-configured, mpls: Not-configured CHAP state: Closed PAP state: Success Protocol inet, MTU: 65531 Flags: Sendbcast-pkt-to-re Addresses, Flags: Is-Primary Local: 77.1.1.1 Protocol inet6, MTU: 65531 Addresses, Flags: Is-Preferred Is-Primary Destination: 2010:0:0:8::/64, Local: 2010:0:0:8::1 Local: fe80::2a0:a50f:fc63:a842
Meaning
The Underlying interface field shows the underlying Ethernet interface configured in the example.
The Destination field under Protocol inet6 shows the IPv6 address obtained through NDRA. This is the value of the $junos-ipv6-ndra-prefix variable configured in the dynamic profile.
The Local field under Protocol inet6 shows the value of the $junos-ipv6-address variable configured for family inet6 in the pp0 configuration of the dynamic profile.