As shown in Figure 1, there are four steps to configure a router as a DHCPv6 server:

Step 1. Enable IPv6 Routing

Use the ipv6 unicast-routing command is required to enable IPv6 routing. This command is not necessary for the router to be a stateless DHCPv6 server, but is required for sending ICMPv6 RA messages.

Step 2. Configure a DHCPv6 Pool

The ipv6 dhcp pool pool-name command creates a pool and enters the router in DHCPv6 configuration mode, which is identified by the Router(config-dhcpv6)# prompt.

Step 3. Configure Pool Parameters

During the SLAAC process the client received the information it needed to create an IPv6 global unicast address. The client also received the default gateway information using the source IPv6 address from the RA message, which is the link-local address of the router. However, the stateless DHCPv6 server can be configured to provide other information that might not have been included in the RA message such as DNS server address and the domain name.

Step 4. Configure the DHCPv6 Interface

The ipv6 dhcp server pool-name interface configuration mode command binds the DHCPv6 pool to the interface. The router responds to stateless DHCPv6 requests on this interface with the information contained in the pool. The O flag needs to be changed from 0 to 1 using the interface command ipv6 nd other-config-flag. RA messages sent on this interface indicate that additional information is available from a stateless DHCPv6 server.

DHCPv6 Stateless Server Example

Figure 2 shows a sample configuration for a router to be configured as a stateless DHCPv6 server. Notice that router R3 is shown as a DHCPv6 client. R3 is configured as a client to help verify the stateless DHCPv6 operations.