Index: libnetutil/netutil.cc
===================================================================
--- libnetutil/netutil.cc	(revision 25615)
+++ libnetutil/netutil.cc	(working copy)
@@ -1311,10 +1311,11 @@
   return -1;
 }
 
-/* Looks for an interface with the given name (iname), and returns the
-   corresponding interface_info if found.  Will accept a match of
-   devname or devfullname.  Returns NULL if none found */
-struct interface_info *getInterfaceByName(const char *iname) {
+/* Looks for an interface with the given name (iname) and address
+   family type, and returns the corresponding interface_info if found.
+   Will accept a match of devname or devfullname. Returns NULL if
+   none found */
+struct interface_info *getInterfaceByName(const char *iname, u16 family) {
   struct interface_info *ifaces;
   int numifaces = 0;
   int ifnum;
@@ -1322,8 +1323,9 @@
   ifaces = getinterfaces(&numifaces, NULL, 0);
 
   for (ifnum = 0; ifnum < numifaces; ifnum++) {
-    if (strcmp(ifaces[ifnum].devfullname, iname) == 0 ||
-        strcmp(ifaces[ifnum].devname, iname) == 0)
+    if ((strcmp(ifaces[ifnum].devfullname, iname) == 0 ||
+        strcmp(ifaces[ifnum].devname, iname) == 0) &&
+        ifaces[ifnum].addr.ss_family == family)
       return &ifaces[ifnum];
   }
 
@@ -2993,7 +2995,7 @@
   struct interface_info *ii;
   ii = NULL;
   if (device != NULL && device[0] != '\0') {
-    ii = getInterfaceByName(device);
+    ii = getInterfaceByName(device, rtmsg->rtm_family);
     if (ii == NULL)
       netutil_fatal("Could not find interface %s which was specified by -e", device);
   }
@@ -3012,7 +3014,7 @@
       intf_index = *(int *) RTA_DATA(rtattr);
       rc = intf_name(intf_index, namebuf, sizeof(namebuf));
       assert(rc != -1);
-      ii = getInterfaceByName(namebuf);
+      ii = getInterfaceByName(namebuf, rtmsg->rtm_family);
       if (ii == NULL)
         netutil_fatal("%s: can't find interface \"%s\"", __func__, namebuf);
     } else if (rtattr->rta_type == RTA_PREFSRC && rnfo->srcaddr.ss_family == AF_UNSPEC) {
@@ -3108,7 +3110,7 @@
   }
 
   if (device!=NULL && device[0]!='\0'){
-    iface = getInterfaceByName(device);
+    iface = getInterfaceByName(device, dst->ss_family);
     if (!iface)
       netutil_fatal("Could not find interface %s which was specified by -e", device);
   } else {
Index: libnetutil/netutil.h
===================================================================
--- libnetutil/netutil.h	(revision 25615)
+++ libnetutil/netutil.h	(working copy)
@@ -357,10 +357,11 @@
   int numifaces;
 };
 
-/* Looks for an interface with the given name (iname), and returns the
-   corresponding interface_info if found.  Will accept a match of
-   devname or devfullname.  Returns NULL if none found */
-struct interface_info *getInterfaceByName(const char *iname);
+/* Looks for an interface with the given name (iname) and address
+   family type, and returns the corresponding interface_info if found.
+   Will accept a match of devname or devfullname. Returns NULL if
+   none found */
+struct interface_info *getInterfaceByName(const char *iname, u16 family);
 
 /* Parse the system routing table, converting each route into a
    sys_route entry.  Returns an array of sys_routes.  numroutes is set
Index: nse_dnet.cc
===================================================================
--- nse_dnet.cc	(revision 25615)
+++ nse_dnet.cc	(working copy)
@@ -51,7 +51,8 @@
 {
   char ipstr[INET6_ADDRSTRLEN];
   struct addr src, bcast;
-  struct interface_info *ii = getInterfaceByName(luaL_checkstring(L, 1));
+  struct interface_info *ii = getInterfaceByName(luaL_checkstring(L, 1),
+                                                 o.af());
 
   if (ii == NULL) {
     lua_pushnil(L);
@@ -155,7 +156,7 @@
 {
   nse_dnet_udata *udata = (nse_dnet_udata *) luaL_checkudata(L, 1, DNET_METATABLE);
   const char *interface_name = luaL_checkstring(L, 2);
-  struct interface_info *ii = getInterfaceByName(interface_name);
+  struct interface_info *ii = getInterfaceByName(interface_name, o.af());
 
   if (ii == NULL || ii->device_type != devt_ethernet)
     return luaL_argerror(L, 2, "device is not valid ethernet interface");