In IPv6, the “advertise” option used in the context of router configuration (Router Advertisements, RA) does not completely replace a DHCP server, but it can fulfill some of the basic functions that we traditionally associate with DHCP in IPv4.

This ability to advertise and distribute network configurations without a DHCP server is known as Stateless Address Autoconfiguration (SLAAC).

Differences between Stateless Autoconfiguration (SLAAC) and DHCPv6

1. Stateless Autoconfiguration (SLAAC):

• Operation: Routers send periodic advertisements (Router Advertisements, RAs) that include the network prefix. Client devices use this information to generate their own IP addresses using the provided network prefix and their own locally generated ID (usually based on the MAC address).
• Configured Features: SLAAC mainly configures the IP address of the device. Router Advertisements can also provide other network configuration information, such as the default gateway address and DNS servers if configured to do so (via the RDNSS extension).

2. DHCPv6:

• Operation: DHCPv6 is more robust and allows centralized management of IP configuration and other network options, such as the assignment of multiple IP addresses, advanced configuration options, and detailed handling of network parameters that are not directly related to the IP address .
• Configured Features: In addition to IP addresses, DHCPv6 can assign a wide range of settings, such as DNS, DNS search domains, NTP servers, and more.

When is one or the other used?

• SLAAC It is often sufficient for home networks or small offices where basic network configuration is all that is needed. It is simple and does not require an additional server.
• DHCPv6 It is preferred in enterprise environments or larger networks where more granular control over network configuration and IP address space management is needed.

Conclusion

The “advertise” option in the context of IPv6 Router Advertisements does not completely replace a DHCP server, but can function similarly under certain circumstances thanks to SLAAC.

However, for more detailed and controlled network management, DHCPv6 is still necessary and provides capabilities beyond the capabilities of stateless autoconfiguration.