$NetBSD$

--- configure.ac.orig	2011-04-14 21:30:08.000000000 +0000
+++ configure.ac
@@ -375,6 +375,7 @@ if test "${WIN32}" != "yes"; then
 		 sys/mman.h fcntl.h sys/file.h stdlib.h stdint.h dnl
 		 stdarg.h unistd.h signal.h stdio.h string.h dnl
 		 strings.h ctype.h errno.h syslog.h pwd.h grp.h dnl
+		 net/if_tap.h
 		 net/if_tun.h net/tun/if_tun.h stropts.h sys/sockio.h dnl
 		 netinet/in.h netinet/in_systm.h dnl
 		 netinet/tcp.h arpa/inet.h dnl
@@ -407,6 +408,9 @@ if test "${WIN32}" != "yes"; then
 		  #ifdef HAVE_SYS_SOCKET_H
 		  # include <sys/socket.h>
 		  #endif
+		  #ifdef HAVE_NET_IF_H
+		  # include <net/if.h>
+		  #endif
 		  #ifdef HAVE_NETINET_IN_H
 		  # include <netinet/in.h>
 		  #endif
