diff --git a/lib/isc/include/isc/sockaddr.h b/lib/isc/include/isc/sockaddr.h
index 9f3986b01f..97349a3343 100644
--- a/lib/isc/include/isc/sockaddr.h
+++ b/lib/isc/include/isc/sockaddr.h
@@ -245,4 +245,11 @@ isc_sockaddr_fromsockaddr(isc_sockaddr_t *isa, const struct sockaddr *sa);
  * Minimum size of array to pass to isc_sockaddr_format().
  */
 
+bool
+isc_sockaddr_disabled(const isc_sockaddr_t *sockaddr);
+/*%<
+ * Report whether or not the address family of 'sockaddr'
+ * has been disabled.
+ */
+
 ISC_LANG_ENDDECLS
diff --git a/lib/isc/sockaddr.c b/lib/isc/sockaddr.c
index 038e3ec7c4..cf3e7612a9 100644
--- a/lib/isc/sockaddr.c
+++ b/lib/isc/sockaddr.c
@@ -497,3 +497,15 @@ isc_sockaddr_fromsockaddr(isc_sockaddr_t *isa, const struct sockaddr *sa) {
 
 	return (ISC_R_SUCCESS);
 }
+
+bool
+isc_sockaddr_disabled(const isc_sockaddr_t *sockaddr) {
+	if ((sockaddr->type.sa.sa_family == AF_INET &&
+	     isc_net_probeipv4() == ISC_R_DISABLED) ||
+	    (sockaddr->type.sa.sa_family == AF_INET6 &&
+	     isc_net_probeipv6() == ISC_R_DISABLED))
+	{
+		return (true);
+	}
+	return (false);
+}