We all know that IPv6 handles host network parameter initialization a bit different than IPv4 (where we usually use DHCP), but the details could still confuse you if you’re just entering the IPv6 world.

A typical LAN-attached hosts needs its own address as well as the addresses of the default router and DNS server. DHCPv4 provides all three; in the IPv6 world you need two or three protocols as summarized in the following table

Parameter	DHCPv4	DHCPv61	SLAAC2	RA3
Host address	✅	✅ 4	✅	❌
Default router	✅	❌		✅
DNS server	✅	✅		✅ 5
DNS search list	✅	✅		✅ 5

This is how I would set up a typical IPv6 subnet:

• Unless you want to have tight control over host IPv6 addresses, deploy DHCPv6 servers on the routers without associated IPv6 address pools. DHCPv6 should be used just to pass the DNS information to the hosts;
• Enable RA on all LAN interfaces. If your LAN switches support RA guard, you should enable it to prevent RA spoofing and MITM attacks. RA is enabled by default on most LAN interfaces (but check BVI, SVI and wireless interfaces).
• Use RA RDNSS option whenever possible, making sure even broken operating systems without DHCPv6 support get IPv6 DNS information.
• Use SLAAC with privacy extensions. RA is enabled, so SLAAC works; use of privacy extensions has to be configured on the host (it’s enabled by default on most modern operating systems).
• Use DNS server that supports dynamic host registration. Dynamically-assigned (and frequently changing) IPv6 addresses can turn your troubleshooting efforts into a nightmare. If the IPv6 hosts register their addresses with your DNS server, you’ll have at least a fighting change.