IPv6 Addressing Configuration

Enabling Automatic Configuration of a Global Unicast Address and a Default Router Identity on a VLAN

Enabling Automatic Configuration of a Global Unicast Address and a Default Router Identity on a VLAN

Enabling autoconfig or rebooting the switch with autoconfig enabled on a VLAN causes the switch to configure IPv6 addressing on the VLAN using router advertisements and an EUI-64 interface identifier (page 3-14).

Syntax: [no] ipv6 address autoconfig

Implements unicast address autoconfiguration as follows:

■If IPv6 is not already enabled on the VLAN, this command enables IPv6 and generates a link-local (EUI- 64) address.

■Generates router solicitations (RS) on the VLAN.

■If a router advertisement (RA) is received on the VLAN, the switch uses the route prefix in the RA to configure a global unicast address. The device identifier for this address will be the same as the device identifier used in the current link-local address at the time the RA is received. (This can be either a statically configured or the (automatic) EUI-64 device identifier, depending on how the link-local address was configured.) For information on EUI- 64, refer to “Extended Unique Identifier (EUI)” on page 3-14.)If an RA is not received on the VLAN after autoconfig is enabled, a link-local address will be present, but no global unicast addresses will be autoconfigured.

Notes: If a link-local address is already configured on the VLAN, a later, autoconfigured global unicast address uses the same device identifier as the link-local address.

Autoconfigured and DHCPv6-assigned global unicast addresses with the same prefix are mutually exclusive on a VLAN. On a given switch, if both options are configured on the same VLAN, then only the first to acquire a global unicast address will be used.

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