diff --git a/lib/include/srslte/interfaces/ue_interfaces.h b/lib/include/srslte/interfaces/ue_interfaces.h
index c6506cee5..51821f641 100644
--- a/lib/include/srslte/interfaces/ue_interfaces.h
+++ b/lib/include/srslte/interfaces/ue_interfaces.h
@@ -36,6 +36,7 @@
 #include <string>
 
 #include "srslte/asn1/liblte_rrc.h"
+#include "srslte/asn1/liblte_mme.h"
 #include "srslte/common/interfaces_common.h"
 #include "srslte/common/common.h"
 #include "srslte/common/security.h"
@@ -104,8 +105,7 @@ public:
 class gw_interface_nas
 {
 public:
-  virtual srslte::error_t setup_if_addr(uint32_t ip_addr, char *err_str) = 0;
-  virtual srslte::error_t setup_if_addr6(uint8_t *ipv6_if_id, char *err_str) = 0;
+  virtual srslte::error_t setup_if_addr(uint8_t pdn_type, uint32_t ip_addr, uint8_t *ipv6_if_id, char *err_str) = 0;
 };
 
 // GW interface for RRC
diff --git a/srsue/hdr/upper/gw.h b/srsue/hdr/upper/gw.h
index bd178b640..7ab51b962 100644
--- a/srsue/hdr/upper/gw.h
+++ b/srsue/hdr/upper/gw.h
@@ -58,8 +58,7 @@ public:
   void write_pdu_mch(uint32_t lcid, srslte::byte_buffer_t *pdu);
 
   // NAS interface
-  srslte::error_t setup_if_addr(uint32_t ip_addr, char *err_str);
-  srslte::error_t setup_if_addr6(uint8_t *ipv6_if_id, char *err_str);
+  srslte::error_t setup_if_addr(uint8_t pdn_type, uint32_t ip_addr, uint8_t* ipv6_if_addr, char *err_str);
 
   // RRC interface
   void add_mch_port(uint32_t lcid, uint32_t port);
@@ -96,6 +95,8 @@ private:
 
   void                run_thread();
   srslte::error_t     init_if(char *err_str);
+  srslte::error_t setup_if_addr4(uint32_t ip_addr, char *err_str);
+  srslte::error_t setup_if_addr6(uint8_t *ipv6_if_id, char *err_str);
   bool find_ipv6_addr(struct in6_addr *in6_out);
   void del_ipv6_addr(struct in6_addr *in6p);
 
diff --git a/srsue/src/upper/gw.cc b/srsue/src/upper/gw.cc
index b6a620462..f121e5bea 100644
--- a/srsue/src/upper/gw.cc
+++ b/srsue/src/upper/gw.cc
@@ -181,168 +181,27 @@ void gw::write_pdu_mch(uint32_t lcid, srslte::byte_buffer_t *pdu)
 /*******************************************************************************
   NAS interface
 *******************************************************************************/
-srslte::error_t gw::setup_if_addr(uint32_t ip_addr, char *err_str)
+srslte::error_t gw::setup_if_addr(uint8_t pdn_type, uint32_t ip_addr, uint8_t *ipv6_if_addr, char *err_str)
 {
-  if (ip_addr != current_ip_addr) {
-    if(!if_up)
-    {
-      if(init_if(err_str))
-      {
-        gw_log->error("init_if failed\n");
-        return(srslte::ERROR_CANT_START);
-      }
-    }
-
-    // Setup the IP address
-    sock                                                   = socket(AF_INET, SOCK_DGRAM, 0);
-    ifr.ifr_addr.sa_family                                 = AF_INET;
-    ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr = htonl(ip_addr);
-    if(0 > ioctl(sock, SIOCSIFADDR, &ifr))
-    {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to set socket address: %s\n", err_str);
-      close(tun_fd);
-      return(srslte::ERROR_CANT_START);
+  srslte::error_t err;
+  if(pdn_type == LIBLTE_MME_PDN_TYPE_IPV4 || pdn_type == LIBLTE_MME_PDN_TYPE_IPV4V6 ){
+    err = setup_if_addr4(ip_addr, err_str);
+    if(err!= srslte::ERROR_NONE){
+      return err;
     }
-    ifr.ifr_netmask.sa_family                                 = AF_INET;
-    const char *mask = "255.255.255.0";
-    if (!default_netmask) {
-      mask = netmask.c_str();
-    }
-    ((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr.s_addr = inet_addr(mask);
-    if(0 > ioctl(sock, SIOCSIFNETMASK, &ifr))
-    {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to set socket netmask: %s\n", err_str);
-      close(tun_fd);
-      return(srslte::ERROR_CANT_START);
-    }
-
-    current_ip_addr = ip_addr;
-
-    // Setup a thread to receive packets from the TUN device
-    start(GW_THREAD_PRIO);
   }
-
-  return(srslte::ERROR_NONE);
-}
-
-srslte::error_t gw::setup_if_addr6(uint8_t *ipv6_if_id, char *err_str)
-{
-  struct sockaddr_in6 sai;
-  struct in6_ifreq ifr6;
-  bool match = true;
-
-  for (int i=0; i<8; i++){
-    if(ipv6_if_id[i] != current_if_id[i]){
-      match = false;
-      break;
-    }
-  }
-
-  if (!match) {
-    if (!if_up) {
-      if( init_if(err_str) ) {
-        gw_log->error("init_if failed\n");
-        return(srslte::ERROR_CANT_START);
-      }
-    }
-
-    // Setup the IP address
-    sock                                                   = socket(AF_INET6, SOCK_DGRAM, 0);
-    ifr.ifr_addr.sa_family                                 = AF_INET6;
-
-    if(inet_pton(AF_INET6, "fe80::", (void *)&sai.sin6_addr) <= 0) {
-      gw_log->error("Bad address\n");
-      return srslte::ERROR_CANT_START;
-    }
-
-    memcpy(&sai.sin6_addr.s6_addr[8], ipv6_if_id, 8);
-    if (ioctl(sock, SIOGIFINDEX, &ifr) < 0) {
-      perror("SIOGIFINDEX");
-      return srslte::ERROR_CANT_START;
-    }
-    ifr6.ifr6_ifindex = ifr.ifr_ifindex;
-    ifr6.ifr6_prefixlen = 64;
-    memcpy((char *) &ifr6.ifr6_addr, (char *) &sai.sin6_addr,
-      sizeof(struct in6_addr));
-
-    if (ioctl(sock, SIOCSIFADDR, &ifr6) < 0) {
-      err_str = strerror(errno);
-      gw_log->error("Could not set IPv6 Link local address. Error %s\n", err_str);
-      return srslte::ERROR_CANT_START;
-    }
-
-    for (int i=0; i<8; i++){
-      current_if_id[i] = ipv6_if_id[i];
+  if(pdn_type == LIBLTE_MME_PDN_TYPE_IPV6 || pdn_type == LIBLTE_MME_PDN_TYPE_IPV4V6 ){
+    err = setup_if_addr6(ipv6_if_addr, err_str);
+    if(err!= srslte::ERROR_NONE){
+      return err;
     }
-
-    // Setup a thread to receive packets from the TUN device
-    start(GW_THREAD_PRIO);
   }
-
-  return(srslte::ERROR_NONE);
+  
+  // Setup a thread to receive packets from the TUN device
+  start(GW_THREAD_PRIO);
+  return srslte::ERROR_NONE;
 }
 
-srslte::error_t gw::init_if(char *err_str)
-{
-  if(if_up)
-  {
-    return(srslte::ERROR_ALREADY_STARTED);
-  }
-
-  // Construct the TUN device
-  tun_fd = open("/dev/net/tun", O_RDWR);
-  gw_log->info("TUN file descriptor = %d\n", tun_fd);
-  if(0 > tun_fd)
-  {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to open TUN device: %s\n", err_str);
-      return(srslte::ERROR_CANT_START);
-  }
-  memset(&ifr, 0, sizeof(ifr));
-  ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
-  strncpy(ifr.ifr_ifrn.ifrn_name, tundevname.c_str(), std::min(tundevname.length(), (size_t)(IFNAMSIZ-1)));
-  ifr.ifr_ifrn.ifrn_name[IFNAMSIZ-1] = 0;
-  if(0 > ioctl(tun_fd, TUNSETIFF, &ifr))
-  {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to set TUN device name: %s\n", err_str);
-      close(tun_fd);
-      return(srslte::ERROR_CANT_START);
-  }
-
-  // Bring up the interface
-  sock = socket(AF_INET, SOCK_DGRAM, 0);
-  if(0 > ioctl(sock, SIOCGIFFLAGS, &ifr))
-  {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to bring up socket: %s\n", err_str);
-      close(tun_fd);
-      return(srslte::ERROR_CANT_START);
-  }
-  ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
-  if(0 > ioctl(sock, SIOCSIFFLAGS, &ifr))
-  {
-      err_str = strerror(errno);
-      gw_log->debug("Failed to set socket flags: %s\n", err_str);
-      close(tun_fd);
-      return(srslte::ERROR_CANT_START);
-  }
-
-  // Delete link-local IPv6 address.
-  struct in6_addr in6p;
-  char addr_str[INET6_ADDRSTRLEN];
-  if(find_ipv6_addr(&in6p)){
-    gw_log->debug("Found link-local IPv6 address: %s\n",inet_ntop(AF_INET6, &in6p, addr_str,INET6_ADDRSTRLEN) );
-    del_ipv6_addr(&in6p);
-  } else {
-    gw_log->warning("Could not find link-local IPv6 address.\n");
-  }
-  if_up = true;
-
-  return(srslte::ERROR_NONE);
-}
 
 
 /*******************************************************************************
@@ -355,8 +214,6 @@ void gw::add_mch_port(uint32_t lcid, uint32_t port)
   }
 }
 
-
-
 /********************/
 /*    GW Receive    */
 /********************/
@@ -453,9 +310,156 @@ void gw::run_thread()
   gw_log->info("GW IP receiver thread exiting.\n");
 }
 
-/********************/
-/* NETLINK Helpers  */
-/********************/
+/**************************/
+/* TUN Interface Helpers  */
+/**************************/
+srslte::error_t gw::init_if(char *err_str)
+{
+  if (if_up) {
+    return (srslte::ERROR_ALREADY_STARTED);
+  }
+
+  // Construct the TUN device
+  tun_fd = open("/dev/net/tun", O_RDWR);
+  gw_log->info("TUN file descriptor = %d\n", tun_fd);
+  if (0 > tun_fd) {
+    err_str = strerror(errno);
+    gw_log->debug("Failed to open TUN device: %s\n", err_str);
+    return (srslte::ERROR_CANT_START);
+  }
+
+  memset(&ifr, 0, sizeof(ifr));
+  ifr.ifr_flags = IFF_TUN | IFF_NO_PI;
+  strncpy(ifr.ifr_ifrn.ifrn_name, tundevname.c_str(), std::min(tundevname.length(), (size_t)(IFNAMSIZ-1)));
+  ifr.ifr_ifrn.ifrn_name[IFNAMSIZ-1] = 0;
+  if (0 > ioctl(tun_fd, TUNSETIFF, &ifr)) {
+    err_str = strerror(errno);
+    gw_log->debug("Failed to set TUN device name: %s\n", err_str);
+    close(tun_fd);
+    return (srslte::ERROR_CANT_START);
+  }
+
+  // Bring up the interface
+  sock = socket(AF_INET, SOCK_DGRAM, 0);
+  if (0 > ioctl(sock, SIOCGIFFLAGS, &ifr)) {
+    err_str = strerror(errno);
+    gw_log->debug("Failed to bring up socket: %s\n", err_str);
+    close(tun_fd);
+    return (srslte::ERROR_CANT_START);
+  }
+  ifr.ifr_flags |= IFF_UP | IFF_RUNNING;
+  if (0 > ioctl(sock, SIOCSIFFLAGS, &ifr)) {
+    err_str = strerror(errno);
+    gw_log->debug("Failed to set socket flags: %s\n", err_str);
+    close(tun_fd);
+    return (srslte::ERROR_CANT_START);
+  }
+
+  // Delete link-local IPv6 address.
+  struct in6_addr in6p;
+  char addr_str[INET6_ADDRSTRLEN];
+  if(find_ipv6_addr(&in6p)){
+    gw_log->debug("Found link-local IPv6 address: %s\n",inet_ntop(AF_INET6, &in6p, addr_str,INET6_ADDRSTRLEN) );
+    del_ipv6_addr(&in6p);
+  } else {
+    gw_log->warning("Could not find link-local IPv6 address.\n");
+  }
+  if_up = true;
+
+  return(srslte::ERROR_NONE);
+}
+
+srslte::error_t gw::setup_if_addr4(uint32_t ip_addr, char *err_str)
+{
+  if (ip_addr != current_ip_addr) {
+    if (!if_up) {
+      if (init_if(err_str)) {
+        gw_log->error("init_if failed\n");
+        return (srslte::ERROR_CANT_START);
+      }
+    }
+
+    // Setup the IP address
+    sock = socket(AF_INET, SOCK_DGRAM, 0);
+    ifr.ifr_addr.sa_family = AF_INET;
+    ((struct sockaddr_in *)&ifr.ifr_addr)->sin_addr.s_addr = htonl(ip_addr);
+    if (0 > ioctl(sock, SIOCSIFADDR, &ifr)) {
+      err_str = strerror(errno);
+      gw_log->debug("Failed to set socket address: %s\n", err_str);
+      close(tun_fd);
+      return (srslte::ERROR_CANT_START);
+    }
+    ifr.ifr_netmask.sa_family = AF_INET;
+    const char *mask = "255.255.255.0";
+    if (!default_netmask) {
+      mask = netmask.c_str();
+    }
+    ((struct sockaddr_in *)&ifr.ifr_netmask)->sin_addr.s_addr = inet_addr(mask);
+    if (0 > ioctl(sock, SIOCSIFNETMASK, &ifr)) {
+      err_str = strerror(errno);
+      gw_log->debug("Failed to set socket netmask: %s\n", err_str);
+      close(tun_fd);
+      return (srslte::ERROR_CANT_START);
+    }
+    current_ip_addr = ip_addr;
+  }
+  return(srslte::ERROR_NONE);
+}
+
+srslte::error_t gw::setup_if_addr6(uint8_t *ipv6_if_id, char *err_str)
+{
+  struct sockaddr_in6 sai;
+  struct in6_ifreq ifr6;
+  bool match = true;
+
+  for (int i=0; i<8; i++){
+    if(ipv6_if_id[i] != current_if_id[i]){
+      match = false;
+      break;
+    }
+  }
+
+  if (!match) {
+    if (!if_up) {
+      if( init_if(err_str) ) {
+        gw_log->error("init_if failed\n");
+        return(srslte::ERROR_CANT_START);
+      }
+    }
+
+    // Setup the IP address
+    sock = socket(AF_INET6, SOCK_DGRAM, 0);
+    ifr.ifr_addr.sa_family = AF_INET6;
+
+    if(inet_pton(AF_INET6, "fe80::", (void *)&sai.sin6_addr) <= 0) {
+      gw_log->error("Bad address\n");
+      return srslte::ERROR_CANT_START;
+    }
+
+    memcpy(&sai.sin6_addr.s6_addr[8], ipv6_if_id, 8);
+    if (ioctl(sock, SIOGIFINDEX, &ifr) < 0) {
+      perror("SIOGIFINDEX");
+      return srslte::ERROR_CANT_START;
+    }
+    ifr6.ifr6_ifindex = ifr.ifr_ifindex;
+    ifr6.ifr6_prefixlen = 64;
+    memcpy((char *) &ifr6.ifr6_addr, (char *) &sai.sin6_addr,
+      sizeof(struct in6_addr));
+
+    if (ioctl(sock, SIOCSIFADDR, &ifr6) < 0) {
+      err_str = strerror(errno);
+      gw_log->error("Could not set IPv6 Link local address. Error %s\n", err_str);
+      return srslte::ERROR_CANT_START;
+    }
+
+    for (int i=0; i<8; i++){
+      current_if_id[i] = ipv6_if_id[i];
+    }
+  }
+
+  return(srslte::ERROR_NONE);
+}
+
 bool gw::find_ipv6_addr(struct in6_addr *in6_out)
 {
   int status, rtattrlen, fd = -1;
diff --git a/srsue/src/upper/nas.cc b/srsue/src/upper/nas.cc
index 0304ab5e4..658a8a920 100644
--- a/srsue/src/upper/nas.cc
+++ b/srsue/src/upper/nas.cc
@@ -662,7 +662,7 @@ void nas::parse_attach_accept(uint32_t lcid, byte_buffer_t *pdu) {
 
       // Setup GW
       char *err_str = NULL;
-      if (gw->setup_if_addr(ip_addr, err_str)) {
+      if (gw->setup_if_addr(LIBLTE_MME_PDN_TYPE_IPV4, ip_addr, NULL, err_str)) {
         nas_log->error("Failed to set gateway address - %s\n", err_str);
       }
     } else if (LIBLTE_MME_PDN_TYPE_IPV6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type){
@@ -689,7 +689,7 @@ void nas::parse_attach_accept(uint32_t lcid, byte_buffer_t *pdu) {
                        act_def_eps_bearer_context_req.pdn_addr.addr[7]);
       // Setup GW
       char *err_str = NULL;
-      if (gw->setup_if_addr6(ipv6_if_id, err_str)) {
+      if (gw->setup_if_addr(LIBLTE_MME_PDN_TYPE_IPV6, 0, ipv6_if_id, err_str)) {
         nas_log->error("Failed to set gateway address - %s\n", err_str);
       }
     } else if (LIBLTE_MME_PDN_TYPE_IPV4V6 == act_def_eps_bearer_context_req.pdn_addr.pdn_type){ 
@@ -734,10 +734,7 @@ void nas::parse_attach_accept(uint32_t lcid, byte_buffer_t *pdu) {
                        act_def_eps_bearer_context_req.pdn_addr.addr[11]);
       
       char *err_str = NULL;
-      if (gw->setup_if_addr(ip_addr, err_str)) {
-        nas_log->error("Failed to set gateway address - %s\n", err_str);
-      }
-      if (gw->setup_if_addr6(ipv6_if_id, err_str)) {
+      if (gw->setup_if_addr(LIBLTE_MME_PDN_TYPE_IPV4V6, ip_addr, ipv6_if_id, err_str)) {
         nas_log->error("Failed to set gateway address - %s\n", err_str);
       }
     } else {
diff --git a/srsue/test/upper/nas_test.cc b/srsue/test/upper/nas_test.cc
index 92865d705..486f0a739 100644
--- a/srsue/test/upper/nas_test.cc
+++ b/srsue/test/upper/nas_test.cc
@@ -126,8 +126,7 @@ private:
 
 class gw_dummy : public gw_interface_nas, public gw_interface_pdcp
 {
-  error_t setup_if_addr(uint32_t ip_addr, char *err_str) { return ERROR_NONE; }
-  error_t setup_if_addr6(uint8_t *ipv6_if_id, char *err_str) { return ERROR_NONE; }
+  error_t setup_if_addr(uint8_t pdn_type, uint32_t ip_addr, uint8_t *ipv6_if_id, char *err_str) { return ERROR_NONE; }
   void write_pdu(uint32_t lcid, byte_buffer_t *pdu) {}
   void write_pdu_mch(uint32_t lcid, srslte::byte_buffer_t *sdu) {}
 };