diff --git a/include/utils.h b/include/utils.h
index cf1fa4b..4f44505 100644
--- a/include/utils.h
+++ b/include/utils.h
@@ -11,7 +11,9 @@ namespace Tins {
         uint32_t ip_to_int(const std::string &ip);
         std::string ip_to_string(uint32_t ip);
 
-        inline uint32_t ntohl(uint32_t address) {
+        uint32_t resolve_ip(const std::string &to_resolve);
+
+        inline uint32_t net_to_host_l(uint32_t address) {
             return (((address & 0xff000000) >> 24) |
                     ((address & 0x00ff0000) >> 8)  |
                     ((address & 0x0000ff00) << 8)  |
diff --git a/src/ip.cpp b/src/ip.cpp
index 19306fe..6297999 100644
--- a/src/ip.cpp
+++ b/src/ip.cpp
@@ -14,9 +14,9 @@ using namespace std;
 Tins::IP::IP(const string &ip_dst, const string &ip_src) : PDU(IPPROTO_IP) {
     init_ip_fields();
     if(ip_dst.size())
-        _ip.daddr = Utils::ip_to_int(ip_dst);
+        _ip.daddr = Utils::resolve_ip(ip_dst);
     if(ip_src.size())
-        _ip.saddr = Utils::ip_to_int(ip_src);
+        _ip.saddr = Utils::resolve_ip(ip_src);
 
 }
 
@@ -64,7 +64,7 @@ void Tins::IP::check(uint16_t new_check) {
 }
 
 void Tins::IP::source_address(const string &ip) {
-    _ip.saddr = Utils::ip_to_int(ip);
+    _ip.saddr = Utils::resolve_ip(ip);
 }
 
 void Tins::IP::source_address(uint32_t ip) {
@@ -72,7 +72,7 @@ void Tins::IP::source_address(uint32_t ip) {
 }
 
 void Tins::IP::dest_address(const string &ip) {
-    _ip.daddr = Utils::ip_to_int(ip);
+    _ip.daddr = Utils::resolve_ip(ip);
 }
 
 void Tins::IP::dest_address(uint32_t ip) {
@@ -86,23 +86,25 @@ uint32_t Tins::IP::header_size() const {
 }
 
 bool Tins::IP::send(PacketSender* sender) {
-
     struct sockaddr_in link_addr;
-
     link_addr.sin_family = AF_INET;
     link_addr.sin_port = 0;
     link_addr.sin_addr.s_addr = _ip.daddr;
 
     return sender->send_l3(this, (const struct sockaddr*)&link_addr, sizeof(link_addr));
-
 }
 
 void Tins::IP::write_serialization(uint8_t *buffer, uint32_t total_sz) {
     uint32_t my_sz = header_size() + trailer_size();
-    uint32_t new_flag = inner_pdu()? inner_pdu()->flag() : 255;
+    uint32_t new_flag;
     assert(total_sz >= my_sz);
-    if(new_flag == IPPROTO_IP)
-        new_flag = IPPROTO_IPIP;
+    if(inner_pdu()) {
+        new_flag = inner_pdu()->flag();    
+        if(new_flag == IPPROTO_IP)
+            new_flag = IPPROTO_IPIP;
+    }
+    else
+        new_flag = IPPROTO_IP;
     flag(new_flag);
     _ip.protocol = new_flag;
     _ip.tot_len = total_sz;
diff --git a/src/utils.cpp b/src/utils.cpp
index b27b544..abfd8f6 100644
--- a/src/utils.cpp
+++ b/src/utils.cpp
@@ -1,5 +1,9 @@
 #include <stdexcept>
 #include <sstream>
+#include <cassert>
+#ifndef WIN32
+    #include <netdb.h>
+#endif
 #include "utils.h"
 
 using namespace std;
@@ -22,13 +26,13 @@ uint32_t Tins::Utils::ip_to_int(const string &ip) {
     }
     if(bytes_found < 4 || (i < ip.size() && bytes_found == 4))
         throw std::runtime_error("Invalid ip address");
-    return ntohl(result);
+    return net_to_host_l(result);
 }
 
 string Tins::Utils::ip_to_string(uint32_t ip) {
     ostringstream oss;
     int mask(24);
-    ip = ntohl(ip);
+    ip = net_to_host_l(ip);
     while(mask >=0) {
         oss << ((ip >> mask) & 0xff);
         if(mask)
@@ -37,3 +41,10 @@ string Tins::Utils::ip_to_string(uint32_t ip) {
     }
     return oss.str();
 }
+
+uint32_t Tins::Utils::resolve_ip(const string &to_resolve) {
+    struct hostent *data = gethostbyname(to_resolve.c_str());
+    if(!data)
+        return 0;
+    return ((struct in_addr**)data->h_addr_list)[0]->s_addr;
+}