What are the four messages of a Stateful DHCPv6 exchange, and what IPv4 process do they mirror?

Solicit → Advertise → Request → Reply (SARR) — the IPv6 counterpart to DHCPv4's DORA (Discover, Offer, Request, Ack).

* DHCPv6 SARR exchange, the IPv6 counterpart of DHCPv4 DORA. *

After the host has seen a Router Advertisement with the M-flag set, the full DHCPv6 conversation runs in four steps:

1. Solicit — client multicasts "any DHCPv6 servers out there?" (to ff02::1:2, all DHCPv6 servers)
2. Advertise — server replies "I'm here and can serve you"
3. Request — client asks that server for the address/config
4. Reply — server assigns the address and parameters

So it maps neatly onto DHCPv4's DORA: Solicit≈Discover, Advertise≈Offer, Request≈Request, Reply≈Ack.

Tip: Remember SARR for DHCPv6 vs DORA for DHCPv4 — same four-step rhythm, different names. (A client that already knows its server can use a faster 2-message Solicit/Reply with the Rapid Commit option.)