add options to use RDNSS and IPv6 queuing

Author: JojoS62

connectivity/lwipstack/include/lwipstack/lwipopts.h

@@ -207,8 +207,8 @@
 // Fragmentation on, as per IPv4 default
 #define LWIP_IPV6_FRAG              LWIP_IPV6
 
-// Queuing "disabled", as per IPv4 default (so actually queues 1)
-#define LWIP_ND6_QUEUEING           0
+// Queuing, default is  "disabled", as per IPv4 default (so actually queues 1)
+#define LWIP_ND6_QUEUEING           MBED_CONF_ND6_QUEUEING
 
 // Debug Options
 #define NETIF_DEBUG                 LWIP_DBG_OFF
@@ -336,4 +336,6 @@
 #define LWIP_USE_EXTERNAL_MBEDTLS       0
 #endif
 
+#define LWIP_ND6_RDNSS_MAX_DNS_SERVERS  MBED_CONF_LWIP_ND6_RDNSS_MAX_DNS_SERVERS
+
 #endif /* LWIPOPTS_H_ */

connectivity/lwipstack/mbed_lib.json

@@ -153,6 +153,14 @@
         "raw-socket-enabled": {
             "help": "Enable lwip raw sockets, required for Mbed OS ICMPSocket",
             "value": false
+        },
+        "nd6-rdnss-max-dns-servers" : {
+            "help": "number of RDNS from RA (router advertisements) to be used, RFC5006",
+            "value": 2
+        },
+        "nd6_queueing": {
+            "help": "queue outgoing IPv6 packets while MAC address is being resolved",
+            "value": 0
         }
     },
     "target_overrides": {