The ipv6 address auto global command enables stateless IPv6 address autoconfiguration.
The undo ipv6 address auto global command disables stateless IPv6 address autoconfiguration.
By default, stateless IPv6 address autoconfiguration is disabled.
| Parameter | Description | Value |
|---|---|---|
local-identifier |
Use interface identifier of link-local address. |
Only BDIF interface support. |
default |
Learns the source IP address of the received router advertisement (RA) packet and uses the source address as the destination address of the default route. |
Dialer interface do not support this parameter. |
Ethernet interface view, Ethernet sub-interface view, VLAN interface view, Eth-Trunk interface view, Eth-Trunk sub-interface view, loopback interface view, or BDIF interface view
Usage Scenario
Compared with IPv4 using a 32-bit IP address, IPv6 using a 128-bit IP address provides more address space for a network. IPv6 address autoconfiguration and readdressing can reduce the number of devices to be maintained.
After the ipv6 address auto global command is run, IPv6 global addresses will be automatically generated on the interface of the device where RA packets are received. The generated IPv6 addresses contain prefixes of PR packets and the interface ID of the host. If there are no routing devices on the link, the host can only automatically configure the local link address to communicate with the local device.
After the ipv6 address auto global default command is run on an interface and the interface receives an RA packet, an IPv6 address will be generated for the interface. The interface will learn the source IP address of the RA packet and uses the source IP address as the destination address of the default route.
Prerequisites
The ipv6 enable command is run to enable IPv6 on the interfaces.
Configuration Impact
After the ipv6 address auto global command is run on an interface, if the interface receives a new RA packet, an IPv6 address will be generated on the interface, but the default routes learned by the interface will not be deleted.
If an interface has been configured with an IPv6 address, the original IPv6 address will not be deleted after the interface receives an RA packet and generates a new IPv6 address. If the peer router stops sending RA packets, and the automatically generated IPv6 address on the interface expires, the address will be deleted and the original IPv6 address takes effect on the interface.
Precautions
An interface can learn a maximum of three default routes from RA packets and the latest configuration cannot override the previous configurations. The extra routes will be discarded. If multiple default routes have the same priority, packets will be forwarded in load balancing mode.