diff --git a/src/api/netdb.c b/src/api/netdb.c
index 6cf74692..225be257 100644
--- a/src/api/netdb.c
+++ b/src/api/netdb.c
@@ -342,9 +342,9 @@ lwip_getaddrinfo(const char *nodename, const char *servname,
   } else {
     /* service location specified, use loopback address */
     if ((hints != NULL) && (hints->ai_flags & AI_PASSIVE)) {
-      ip_addr_set_any(ai_family == AF_INET6, &addr);
+      ip_addr_set_any_val(ai_family == AF_INET6, addr);
     } else {
-      ip_addr_set_loopback(ai_family == AF_INET6, &addr);
+      ip_addr_set_loopback_val(ai_family == AF_INET6, addr);
     }
   }
 
diff --git a/src/api/sockets.c b/src/api/sockets.c
index 3dfab008..92daea8d 100644
--- a/src/api/sockets.c
+++ b/src/api/sockets.c
@@ -117,7 +117,7 @@ static void sockaddr_to_ipaddr_port(const struct sockaddr* sockaddr, ip_addr_t*
        ((((name)->sa_family == AF_INET) && !(NETCONNTYPE_ISIPV6((sock)->conn->type))) || \
        (((name)->sa_family == AF_INET6) && (NETCONNTYPE_ISIPV6((sock)->conn->type))))
 #define IPADDR_PORT_TO_SOCKADDR(sockaddr, ipaddr, port) do { \
-    if (((ipaddr) && IP_IS_ANY_TYPE_VAL(*ipaddr)) || IP_IS_V6(ipaddr)) { \
+    if (IP_IS_ANY_TYPE_VAL(*ipaddr) || IP_IS_V6_VAL(*ipaddr)) { \
       IP6ADDR_PORT_TO_SOCKADDR((struct sockaddr_in6*)(void*)(sockaddr), ip_2_ip6(ipaddr), port); \
     } else { \
       IP4ADDR_PORT_TO_SOCKADDR((struct sockaddr_in*)(void*)(sockaddr), ip_2_ip4(ipaddr), port); \
@@ -947,6 +947,7 @@ lwip_sock_make_addr(struct netconn *conn, ip_addr_t *fromaddr, u16_t port,
 
   LWIP_UNUSED_ARG(conn);
 
+  LWIP_ASSERT("fromaddr != NULL", fromaddr != NULL);
   LWIP_ASSERT("from != NULL", from != NULL);
   LWIP_ASSERT("fromlen != NULL", fromlen != NULL);
 
diff --git a/src/core/ip.c b/src/core/ip.c
index 2e024085..181ebf51 100644
--- a/src/core/ip.c
+++ b/src/core/ip.c
@@ -67,6 +67,49 @@ struct ip_globals ip_data;
 
 const ip_addr_t ip_addr_any_type = IPADDR_ANY_TYPE_INIT;
 
+/**
+ * @ingroup ipaddr
+ * Convert numeric IP address (both versions) into ASCII representation.
+ * returns ptr to static buffer; not reentrant!
+ *
+ * @param addr ip address in network order to convert
+ * @return pointer to a global static (!) buffer that holds the ASCII
+ *         representation of addr
+ */
+char *ipaddr_ntoa(const ip_addr_t *addr)
+{
+  if (addr == NULL) {
+    return NULL;
+  }
+  if (IP_IS_V6(addr)) {
+    return ip6addr_ntoa(ip_2_ip6(addr));
+  } else {
+    return ip4addr_ntoa(ip_2_ip4(addr));
+  }
+}
+
+/**
+ * @ingroup ipaddr
+ * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
+ *
+ * @param addr ip address in network order to convert
+ * @param buf target buffer where the string is stored
+ * @param buflen length of buf
+ * @return either pointer to buf which now holds the ASCII
+ *         representation of addr or NULL if buf was too small
+ */
+char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen)
+{
+  if (addr == NULL) {
+    return NULL;
+  }
+  if (IP_IS_V6(addr)) {
+    return ip6addr_ntoa_r(ip_2_ip6(addr), buf, buflen);
+  } else {
+    return ip4addr_ntoa_r(ip_2_ip4(addr), buf, buflen);
+  }
+}
+
 /**
  * @ingroup ipaddr
  * Convert IP address string (both versions) to numeric.
diff --git a/src/core/ipv4/ip4_addr.c b/src/core/ipv4/ip4_addr.c
index 2d479923..f0ee4fba 100644
--- a/src/core/ipv4/ip4_addr.c
+++ b/src/core/ipv4/ip4_addr.c
@@ -281,7 +281,7 @@ ip4addr_ntoa(const ip4_addr_t *addr)
 }
 
 /**
- * Same as ipaddr_ntoa, but reentrant since a user-supplied buffer is used.
+ * Same as ip4addr_ntoa, but reentrant since a user-supplied buffer is used.
  *
  * @param addr ip address in network order to convert
  * @param buf target buffer where the string is stored
diff --git a/src/include/lwip/ip_addr.h b/src/include/lwip/ip_addr.h
index 7192c45c..3cca8ef2 100644
--- a/src/include/lwip/ip_addr.h
+++ b/src/include/lwip/ip_addr.h
@@ -143,6 +143,9 @@ extern const ip_addr_t ip_addr_any_type;
 #define ip_addr_set_ip4_u32(ipaddr, val)  do{if(ipaddr){ip4_addr_set_u32(ip_2_ip4(ipaddr), val); \
   IP_SET_TYPE(ipaddr, IPADDR_TYPE_V4); }}while(0)
 /** @ingroup ip4addr */
+#define ip_addr_set_ip4_u32_val(ipaddr, val)  do{ ip4_addr_set_u32(ip_2_ip4(&(ipaddr)), val); \
+  IP_SET_TYPE_VAL(ipaddr, IPADDR_TYPE_V4); }while(0)
+/** @ingroup ip4addr */
 #define ip_addr_get_ip4_u32(ipaddr)  (((ipaddr) && IP_IS_V4(ipaddr)) ? \
   ip4_addr_get_u32(ip_2_ip4(ipaddr)) : 0)
 /** @ingroup ipaddr */
@@ -165,10 +168,18 @@ extern const ip_addr_t ip_addr_any_type;
   ip6_addr_set_any(ip_2_ip6(ipaddr)); IP_SET_TYPE(ipaddr, IPADDR_TYPE_V6); }else{ \
   ip4_addr_set_any(ip_2_ip4(ipaddr)); IP_SET_TYPE(ipaddr, IPADDR_TYPE_V4); }}while(0)
 /** @ingroup ipaddr */
+#define ip_addr_set_any_val(is_ipv6, ipaddr)      do{if(is_ipv6){ \
+  ip6_addr_set_any(ip_2_ip6(&(ipaddr))); IP_SET_TYPE_VAL(ipaddr, IPADDR_TYPE_V6); }else{ \
+  ip4_addr_set_any(ip_2_ip4(&(ipaddr))); IP_SET_TYPE_VAL(ipaddr, IPADDR_TYPE_V4); }}while(0)
+/** @ingroup ipaddr */
 #define ip_addr_set_loopback(is_ipv6, ipaddr) do{if(is_ipv6){ \
   ip6_addr_set_loopback(ip_2_ip6(ipaddr)); IP_SET_TYPE(ipaddr, IPADDR_TYPE_V6); }else{ \
   ip4_addr_set_loopback(ip_2_ip4(ipaddr)); IP_SET_TYPE(ipaddr, IPADDR_TYPE_V4); }}while(0)
 /** @ingroup ipaddr */
+#define ip_addr_set_loopback_val(is_ipv6, ipaddr) do{if(is_ipv6){ \
+  ip6_addr_set_loopback(ip_2_ip6(&(ipaddr))); IP_SET_TYPE_VAL(ipaddr, IPADDR_TYPE_V6); }else{ \
+  ip4_addr_set_loopback(ip_2_ip4(&(ipaddr))); IP_SET_TYPE_VAL(ipaddr, IPADDR_TYPE_V4); }}while(0)
+/** @ingroup ipaddr */
 #define ip_addr_set_hton(dest, src)  do{if(IP_IS_V6(src)){ \
   ip6_addr_set_hton(ip_2_ip6(ipaddr), (src)); IP_SET_TYPE(dest, IPADDR_TYPE_V6); }else{ \
   ip4_addr_set_hton(ip_2_ip4(ipaddr), (src)); IP_SET_TYPE(dest, IPADDR_TYPE_V4); }}while(0)
@@ -214,12 +225,8 @@ extern const ip_addr_t ip_addr_any_type;
 #define ip_addr_debug_print_val(debug, ipaddr) do { if(IP_IS_V6_VAL(ipaddr)) { \
   ip6_addr_debug_print_val(debug, *ip_2_ip6(&(ipaddr))); } else { \
   ip4_addr_debug_print_val(debug, *ip_2_ip4(&(ipaddr))); }}while(0)
-/** @ingroup ipaddr */
-#define ipaddr_ntoa(addr)   (((addr) == NULL) ? "NULL" : \
-  ((IP_IS_V6(addr)) ? ip6addr_ntoa(ip_2_ip6(addr)) : ip4addr_ntoa(ip_2_ip4(addr))))
-/** @ingroup ipaddr */
-#define ipaddr_ntoa_r(addr, buf, buflen)   (((addr) == NULL) ? "NULL" : \
-  ((IP_IS_V6(addr)) ? ip6addr_ntoa_r(ip_2_ip6(addr), buf, buflen) : ip4addr_ntoa_r(ip_2_ip4(addr), buf, buflen)))
+char *ipaddr_ntoa(const ip_addr_t *addr);
+char *ipaddr_ntoa_r(const ip_addr_t *addr, char *buf, int buflen);
 int ipaddr_aton(const char *cp, ip_addr_t *addr);
 
 /** @ingroup ipaddr */
diff --git a/src/netif/ppp/ppp.c b/src/netif/ppp/ppp.c
index 4b0eb6c1..9009a8d6 100644
--- a/src/netif/ppp/ppp.c
+++ b/src/netif/ppp/ppp.c
@@ -1101,9 +1101,9 @@ int sdns(ppp_pcb *pcb, u32_t ns1, u32_t ns2) {
   ip_addr_t ns;
   LWIP_UNUSED_ARG(pcb);
 
-  ip_addr_set_ip4_u32(&ns, ns1);
+  ip_addr_set_ip4_u32_val(ns, ns1);
   dns_setserver(0, &ns);
-  ip_addr_set_ip4_u32(&ns, ns2);
+  ip_addr_set_ip4_u32_val(ns, ns2);
   dns_setserver(1, &ns);
   return 1;
 }
@@ -1118,12 +1118,12 @@ int cdns(ppp_pcb *pcb, u32_t ns1, u32_t ns2) {
   LWIP_UNUSED_ARG(pcb);
 
   nsa = dns_getserver(0);
-  ip_addr_set_ip4_u32(&nsb, ns1);
+  ip_addr_set_ip4_u32_val(nsb, ns1);
   if (ip_addr_cmp(nsa, &nsb)) {
     dns_setserver(0, IP_ADDR_ANY);
   }
   nsa = dns_getserver(1);
-  ip_addr_set_ip4_u32(&nsb, ns2);
+  ip_addr_set_ip4_u32_val(nsb, ns2);
   if (ip_addr_cmp(nsa, &nsb)) {
     dns_setserver(1, IP_ADDR_ANY);
   }