diff --git a/lib/libc/net/getnameinfo.c b/lib/libc/net/getnameinfo.c
--- a/lib/libc/net/getnameinfo.c
+++ b/lib/libc/net/getnameinfo.c
@@ -229,24 +229,48 @@
 	case AF_INET6:
 	    {
 		const struct sockaddr_in6 *sin6;
+
 		sin6 = (const struct sockaddr_in6 *)sa;
-		switch (sin6->sin6_addr.s6_addr[0]) {
-		case 0x00:
-			if (IN6_IS_ADDR_V4MAPPED(&sin6->sin6_addr))
-				;
-			else if (IN6_IS_ADDR_LOOPBACK(&sin6->sin6_addr))
-				;
-			else
-				flags |= NI_NUMERICHOST;
-			break;
-		default:
-			if (IN6_IS_ADDR_LINKLOCAL(&sin6->sin6_addr)) {
-				flags |= NI_NUMERICHOST;
-			}
-			else if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
-				flags |= NI_NUMERICHOST;
-			break;
-		}
+
+		/*
+		 * https://pubs.opengroup.org/onlinepubs/009604599/functions/getnameinfo.html
+		 * "If the socket address structure contains an IPv4-mapped
+		 * IPv6 address or an IPv4-compatible IPv6 address,
+		 * the implementation shall extract the embedded IPv4 address
+		 * and lookup the node name for that IPv4 address."
+		 * => getipnodebyaddr() handles that case for us.
+		 *
+		 * "Note: The IPv6 unspecified address ( "::" ) and the
+		 * IPv6 loopback address ( "::1" ) are not IPv4-compatible
+		 * addresses."
+		 * => IN6_IS_ADDR_V4COMPAT() handles this (according to
+		 * RFC 2553 6.2 Address-To-Nodename Translation)
+		 *
+		 * "If the address is the IPv6 unspecified address
+		 * ( "::" ), a lookup is not performed, and the [EAI_NONAME]
+		 * error is returned."
+		 * => catch here for proper return value (getipnodebyaddr()
+		 * does as well but not return an appropriate error?)
+		 */
+		if (IN6_IS_ADDR_UNSPECIFIED(&sin6->sin6_addr))
+			return EAI_NONAME;
+
+		/*
+		 * We used to exclude link-local from lookups.
+		 * Even though calles in the resolver chain may not (yet)
+		 * properly deal with them, we no longer do as for link-local
+		 * there is a path to resolve these. See:
+		 * RFC 6303 4.5.  IPv6 Link-Local Addresses
+		 * RFC 6762 4.  Reverse Address Mapping
+		 *
+		 * XXX For IPv6 MC the only reference found was
+		 * https://www.ietf.org/archive/id/draft-michaelson-as112-ipv6-02.html
+		 * but there are also no "empty zone" for x.0.f.f.ip6.arpa
+		 * in DNS servers.  Keep catching it here for now and
+		 * do not attempt name resolution but return address string.
+		 */
+		if (IN6_IS_ADDR_MULTICAST(&sin6->sin6_addr))
+			flags |= NI_NUMERICHOST;
 	    }
 		break;
 #endif