feature: road-warrior clients resolve the domains of the new setting p2s.dns_domains with the router's resolver.

ADR.md

@@ -1201,3 +1201,21 @@ users their own through `/account` with their current password and code.
 Consequences: The password is never stored; the device asks for it when the profile is installed.
 A profile shows as unverified. A changed proposal of `road-warrior.conf` must be changed in the
 profile too. WireGuard is not part of it.
+
+## ADR-45: Road-warrior clients get split DNS domains, p2s.dns_domains
+
+Status: Accepted
+
+Context: The road-warrior access is a split tunnel. macOS and iOS use the DNS server an IKEv2 VPN
+pushes only for queries scoped to the tunnel, so names only the router resolves, such as Azure's
+internal names, fail. RFC 8598 defines INTERNAL_DNS_DOMAIN (attribute 25): the client resolves the
+listed domains and their subdomains with the VPN's servers. strongSwan's pools take numeric
+attributes with string values; Apple profiles name such domains in `SupplementalMatchDomains`.
+
+Decision: The setting `p2s.dns_domains` lists the domains; setup pushes each as attribute 25 of the
+road-warrior pool, and the Apple VPN profile gives them as match domains of the router's resolver,
+the addresses setup records for the web service.
+
+Consequences: Clients resolve the listed domains through the tunnel and everything else with their
+own resolvers. Clients that ignore attribute 25 keep the scoped behaviour; the Apple profile
+covers Apple devices. A changed list reaches an Apple device with a newly installed profile.