Configuring the DHCPv6 relay agent

  • An enabled layer 3 interface.

  1. Enable the DHCPv6 agent with the command dhcpv6-relay.
  2. Configure one or more IP helper addresses with the command ipv6 helper-address. This determines where the DHCPv6 agent forward DHCP requests.
  3. If you want to enable DHCP option 79 support to forward client link-layer addresses, use the command dhcpv6-relay option 79.
  4. Review DHCPv6 relay agent configuration settings with the commands show dhcpv6-relay and show ipv6 helper-address.


This example creates the following configuration:

  • Enables the DHCPv6 relay agent.
  • Enables interface 1/1/2 and assigns an IPv6 address to it. (By default, all interfaces are layer 3 and disabled.)

  • Defines an IP helper address of FF01::1:1000 on interface 1/1/2.
  • Enables DHCP option 79.

switch(config)# dhcpv6-relay
switch(config)# interface 1/1/2
switch(config-if)# no shutdown 
switch(config-if)# ipv6 address 2001:0db8:85a3::8a2e:0370:7334/24 
switch(config-if)# ip helper-address FF01::1:1000 
switch(config-if)# exit 
switch(config)# dhcpv6-relay option 79