diff --git a/tools/sdk/lib/liblwip2-1460-feat.a b/tools/sdk/lib/liblwip2-1460-feat.a
index 8d785324f..862359253 100644
Binary files a/tools/sdk/lib/liblwip2-1460-feat.a and b/tools/sdk/lib/liblwip2-1460-feat.a differ
diff --git a/tools/sdk/lib/liblwip2-1460.a b/tools/sdk/lib/liblwip2-1460.a
index 29b0838b9..b36468446 100644
Binary files a/tools/sdk/lib/liblwip2-1460.a and b/tools/sdk/lib/liblwip2-1460.a differ
diff --git a/tools/sdk/lib/liblwip2-536-feat.a b/tools/sdk/lib/liblwip2-536-feat.a
index c848b6a0f..43beee522 100644
Binary files a/tools/sdk/lib/liblwip2-536-feat.a and b/tools/sdk/lib/liblwip2-536-feat.a differ
diff --git a/tools/sdk/lib/liblwip2-536.a b/tools/sdk/lib/liblwip2-536.a
index 70c5f2dec..aeb3d5c0d 100644
Binary files a/tools/sdk/lib/liblwip2-536.a and b/tools/sdk/lib/liblwip2-536.a differ
diff --git a/tools/sdk/lib/liblwip6-1460-feat.a b/tools/sdk/lib/liblwip6-1460-feat.a
index c45606fd5..e58ef8676 100644
Binary files a/tools/sdk/lib/liblwip6-1460-feat.a and b/tools/sdk/lib/liblwip6-1460-feat.a differ
diff --git a/tools/sdk/lib/liblwip6-536-feat.a b/tools/sdk/lib/liblwip6-536-feat.a
index 2ccea829b..98376c6f4 100644
Binary files a/tools/sdk/lib/liblwip6-536-feat.a and b/tools/sdk/lib/liblwip6-536-feat.a differ
diff --git a/tools/sdk/lwip2/builder b/tools/sdk/lwip2/builder
index 7206349a0..d2f388bf0 160000
--- a/tools/sdk/lwip2/builder
+++ b/tools/sdk/lwip2/builder
@@ -1 +1 @@
-Subproject commit 7206349a0acaa9e042fc56ab3726f3a0ea058416
+Subproject commit d2f388bf070aab74cb4d81d52419a7dc2d36fb81
diff --git a/tools/sdk/lwip2/include/lwip-git-hash.h b/tools/sdk/lwip2/include/lwip-git-hash.h
index efa52f4be..d27d89577 100644
--- a/tools/sdk/lwip2/include/lwip-git-hash.h
+++ b/tools/sdk/lwip2/include/lwip-git-hash.h
@@ -1,5 +1,5 @@
 // generated by makefiles/make-lwip2-hash
 #ifndef LWIP_HASH_H
 #define LWIP_HASH_H
-#define LWIP_HASH_STR "STABLE-2_1_2_RELEASE/glue:1.0-11-g87c709d"
+#define LWIP_HASH_STR "STABLE-2_1_2_RELEASE/glue:1.1"
 #endif // LWIP_HASH_H
diff --git a/tools/sdk/lwip2/include/lwip/apps/sntp.h b/tools/sdk/lwip2/include/lwip/apps/sntp.h
index 3c0f95f72..c4152534f 100644
--- a/tools/sdk/lwip2/include/lwip/apps/sntp.h
+++ b/tools/sdk/lwip2/include/lwip/apps/sntp.h
@@ -67,11 +67,11 @@ void sntp_setservername(u8_t idx, const char *server);
 const char *sntp_getservername(u8_t idx);
 #endif /* SNTP_SERVER_DNS */
 
-#if SNTP_GET_SERVERS_FROM_DHCP
+#if SNTP_GET_SERVERS_FROM_DHCP || SNTP_GET_SERVERS_FROM_DHCPV6
 void sntp_servermode_dhcp(int set_servers_from_dhcp);
-#else /* SNTP_GET_SERVERS_FROM_DHCP */
+#else /* SNTP_GET_SERVERS_FROM_DHCP || SNTP_GET_SERVERS_FROM_DHCPV6 */
 #define sntp_servermode_dhcp(x)
-#endif /* SNTP_GET_SERVERS_FROM_DHCP */
+#endif /* SNTP_GET_SERVERS_FROM_DHCP || SNTP_GET_SERVERS_FROM_DHCPV6 */
 
 #ifdef __cplusplus
 }
diff --git a/tools/sdk/lwip2/include/lwip/apps/sntp_opts.h b/tools/sdk/lwip2/include/lwip/apps/sntp_opts.h
index ed98040fe..cb6277164 100644
--- a/tools/sdk/lwip2/include/lwip/apps/sntp_opts.h
+++ b/tools/sdk/lwip2/include/lwip/apps/sntp_opts.h
@@ -67,6 +67,12 @@
 #define SNTP_GET_SERVERS_FROM_DHCP LWIP_DHCP_GET_NTP_SRV
 #endif
 
+/** Set this to 1 to implement the callback function called by dhcpv6 when
+ * NTP servers are received. */
+#if !defined SNTP_GET_SERVERS_FROM_DHCPV6 || defined __DOXYGEN__
+#define SNTP_GET_SERVERS_FROM_DHCPV6 LWIP_DHCP6_GET_NTP_SRV
+#endif
+
 /** Set this to 1 to support DNS names (or IP address strings) to set sntp servers
  * One server address/name can be defined as default if SNTP_SERVER_DNS == 1:
  * \#define SNTP_SERVER_ADDRESS "pool.ntp.org"
diff --git a/tools/sdk/lwip2/include/lwipopts.h b/tools/sdk/lwip2/include/lwipopts.h
index 7332104c9..b644c4d3c 100644
--- a/tools/sdk/lwip2/include/lwipopts.h
+++ b/tools/sdk/lwip2/include/lwipopts.h
@@ -2705,7 +2705,7 @@
  * void dhcp6_set_ntp_servers(u8_t num_ntp_servers, ip_addr_t* ntp_server_addrs);
 */
 #if !defined LWIP_DHCP6_GET_NTP_SRV || defined __DOXYGEN__
-#define LWIP_DHCP6_GET_NTP_SRV          0 // with 1: dhcp6_set_ntp_servers() must be implemented
+#define LWIP_DHCP6_GET_NTP_SRV          1 // with 1: dhcp6_set_ntp_servers() must be implemented
 #endif
 
 /**