ipv6 helper-address

Syntax

ipv6 helper-address unicast ipv6-unicast-helper-addr

no ipv6 helper-address unicast ipv6-unicast-helper-addr

ipv6 helper-address multicast [all-dhcp-servers|ipv6-unicast-helper-addr][ egress vlan vid]

no ipv6 helper-address multicast [all-dhcp-servers|ipv6-unicast-helper-addr][ egress vlan vid]

Description

Used in the VLAN context to enable DHCPv6-relay operation on the VLAN, and to specify either a unicast or multicast DHCPv6-relay helper address for forwarding DHCPv6 service requests from hosts on the subject VLAN.

Options

ipv6-unicast-helper-addr

Specifies the global unicast address of a remote DHCPv6 server configured to support hosts on the indicated VLAN.

all-dhcp-servers

Specifies that the routing switch forward host requests for DHCPv6 service to multicast address FF05::1:3 via the VLAN specified by egress vlan vid

egress vlan vid

Specifies the VLAN on which DHCPv6 service requests forwarded to a multicast destination will be relayed. The egress VLAN must be a different VLAN than the one on which the multicast helper address is configured.

A service request relayed on the egress VLAN to a downstream router remains in that VLAN unless the downstream router is configured on that VLAN with a unicast helper address for a server on another VLAN.

Using the noform of the command removes the specified helper address. Removing all helper addresses from a given VLAN disables DHCPv6-relay on that VLAN.

NOTE:

DHCPv6-relay operation must be enabled with dhcpv6-relay at the global config level.