# Configuring IPv6 over Frame Relay Interfaces

You can configure IPv6 prefix addresses on Frame Relay interfaces on a packet over SONET (POS) physical interface. IPv6 traffic is forwarded over Frame Relay circuits and the database of the forwarding controller is updated with IPv6 as an upper-layer interface to the Frame Relay layer.

You can specify IPv6 prefixes only on Frame Relay interfaces over POS major interfaces. You cannot configure IPv6 addresses on E3 and T3 interfaces. Because IPv6 neighbor discovery is not supported on POS interfaces, you cannot use a provider edge router that contains Frame Relay or MLFR interfaces configured with IPv6 addresses to respond to route solicitation packets it receives from clients in environments in which the subscriber is either an IPv6 subscriber or a combined IPv4 and IPv6 subscriber in a dual stack.

The following sections describe how to configure IPv6 addresses for Frame Relay interface circuits on POS interfaces that operate as DCE, DTE, or NNI and for Frame Relay PVCs over a POS subinterface:

- Configuring an IPv6 Address for a Frame Relay That Operates as a DCE, DTE, or NNI
- Configuring an IPv6 Address for a Frame Relay PVC

## Configuring an IPv6 Address for a Frame Relay That Operates as a DCE, DTE, or NNI

To configure an IPv6 prefix address for a Frame Relay interface over a POS interface that operates as a DCE, DTE, or NNI:

1. From Configuration mode, enter a POS interface on which you want to configure Frame Relay.
   host1(config)#interface pos 0/1
2. Select Frame Relay as the encapsulation method for the interface.
   host1(config-if)#encapsulation frame-relay ietf
3. (Optional) Assign a text description or an alias to the major interface.
   host1(config-if)#frame-relay description boston01
4. Configure the interface as a DCE, DTE, or NNI.
   host1(config-if)#frame-relay intf-type dte
5. Assign a local IP address to the circuit.
   host1(config-subif)#ipv6 address 1::1/64

## Configuring an IPv6 Address for a Frame Relay PVC

To configure an IPv6 prefix address for a Frame Relay PVC over a POS subinterface:

1. From Configuration mode, enter a POS interface on which you want to configure Frame Relay.
   host1(config)#interface pos 0/1
2. Select Frame Relay as the encapsulation method for the interface.
   host1(config-if)#encapsulation frame-relay ietf
3. (Optional) Assign a text description or an alias to the major interface.
   host1(config-if)#frame-relay description boston01
4. Configure the LMI type.
   host1(config-if)#frame-relay lmi-type ansi
5. (Optional) Configure Frame Relay counters and timers.
   host1(config-if)#frame-relay lmi-n391dte 20
6. Configure the cyclic redundancy check (CRC).
   host1(config-if)#crc 32
7. Create a subinterface.
   host1(config)#interface pos 0/1.1
8. Add a circuit to a subinterface.
   host1(config-subif)#frame-relay interface-dlci 17 ietf
9. Assign a local IP address to the circuit.
   host1(config-subif)#ipv6 address 1::1/64

interface pos

- Use to configure a POS interface in slot/port format:
  - slot—Router chassis slot
  - port—Line module port
- Example
  host1(config)#interface pos 0/1
- Use the no version to remove the POS interface.
- See interface pos.

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.