Configuring an IPv6 link-local address
Configure IPv6 link-local addresses using one of the following methods:
Automatic generation—The device automatically generates a link-local address for an interface according to the link-local address prefix (FE80::/10) and the link-layer address of the interface.
Manual assignment—Manually configure an IPv6 link-local address for an interface.
An interface can have only one link-local address. As a best practice, use the automatic generation method to avoid link-local address conflicts. If both methods are used, the manual assignment takes precedence.
If you first use automatic generation and then manual assignment, the manually assigned link-local address overwrites the automatically generated one.
If you first use manual assignment and then automatic generation, both of the following occur:
The link-local address is still the manually assigned one.
The automatically generated link-local address does not take effect. If you delete the manually assigned address, the automatically generated link-local address takes effect.
Configuring automatic generation of an IPv6 link-local address for an interface
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface interface-type interface-number | N/A |
3. Configure the interface to automatically generate an IPv6 link-local address. | ipv6 address auto link-local | By default, no link-local address is configured on an interface. After an IPv6 global unicast address is configured on the interface, a link-local address is generated automatically. |
Manually specifying an IPv6 link-local address for an interface
Step | Command | Remarks |
|---|---|---|
1. Enter system view. | system-view | N/A |
2. Enter interface view. | interface interface-type interface-number | N/A |
3. Manually specify an IPv6 link-local address for the interface. | ipv6 address ipv6-address link-local | By default, no link-local address is configured on an interface. |
After you configure an IPv6 global unicast address for an interface, the interface automatically generates a link-local address. The automatically generated link-local address is the same as the one generated by using the ipv6 address auto link-local command. If a link-local address is manually assigned to an interface, this manual link-local address takes effect. If the manually assigned link-local address is deleted, the automatically generated link-local address takes effect.
Using the undo ipv6 address auto link-local command on an interface only deletes the link-local address generated by the ipv6 address auto link-local command. If the interface has an IPv6 global unicast address, it still has a link-local address. If the interface has no IPv6 global unicast address, it has no link-local address.