diff --git a/test/test_tap.py b/test/test_tap.py
new file mode 100644
index 0000000..cbee910
--- /dev/null
+++ b/test/test_tap.py
@@ -0,0 +1,87 @@
+import sys
+import optparse
+import socket
+import select
+import errno
+import pytun
+
+class TunnelServer(object):
+
+    def __init__(self, taddr, tmask, tmtu, laddr, lport, raddr, rport):
+        self._tap = pytun.TunTapDevice(flags=pytun.IFF_TAP|pytun.IFF_NO_PI)
+        self._tap.addr = taddr
+        self._tap.netmask = tmask
+        self._tap.mtu = tmtu
+        self._tap.up()
+        self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        self._sock.bind((laddr, lport))
+        self._raddr = raddr
+        self._rport = rport
+
+    def run(self):
+        mtu = self._tap.mtu
+        r = [self._tap, self._sock]; w = []; x = []
+        to_tap = ''
+        to_sock = ''
+        while True:
+            try:
+                r, w, x = select.select(r, w, x)
+                if self._tap in r:
+                    to_sock = self._tap.read(mtu)
+                if self._sock in r:
+                    to_tap, addr = self._sock.recvfrom(65535)
+                    if addr[0] != self._raddr or addr[1] != self._rport:
+                        to_tap = '' # drop packet
+                if self._tap in w:
+                    self._tap.write(to_tap)
+                    to_tap = ''
+                if self._sock in w:
+                    self._sock.sendto(to_sock, (self._raddr, self._rport))
+                    to_sock = ''
+                r = []; w = []
+                if to_tap:
+                    w.append(self._tap)
+                else:
+                    r.append(self._sock)
+                if to_sock:
+                    w.append(self._sock)
+                else:
+                    r.append(self._tap)
+            except (select.error, socket.error, pytun.Error), e:
+                if e[0] == errno.EINTR:
+                    continue
+                print >> sys.stderr, str(e)
+                break
+
+def main():
+    parser = optparse.OptionParser()
+    parser.add_option('--tap-addr', dest='taddr',
+            help='set tunnel local address')
+    parser.add_option('--tap-netmask', default='255.255.255.0',dest='tmask',
+            help='set tunnel netmask')
+    parser.add_option('--tap-mtu', type='int', default=1500,dest='tmtu',
+            help='set tunnel MTU')
+    parser.add_option('--local-addr', default='0.0.0.0', dest='laddr',
+            help='set local address [%default]')
+    parser.add_option('--local-port', type='int', default=12000, dest='lport',
+            help='set local port [%default]')
+    parser.add_option('--remote-addr', dest='raddr',
+            help='set remote address')
+    parser.add_option('--remote-port', type='int', dest='rport',
+            help='set remote port')
+    opt, args = parser.parse_args()
+    if not (opt.taddr and opt.raddr and opt.rport):
+        parser.print_help()
+        return 1
+    try:
+        server = TunnelServer(opt.taddr, opt.tmask, opt.tmtu, opt.laddr,
+                opt.lport, opt.raddr, opt.rport)
+    except (pytun.Error, socket.error), e:
+        print >> sys.stderr, str(e)
+        return 1
+    server.run()
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main())
+
diff --git a/test/test_tun.py b/test/test_tun.py
new file mode 100644
index 0000000..11c5696
--- /dev/null
+++ b/test/test_tun.py
@@ -0,0 +1,90 @@
+import sys
+import optparse
+import socket
+import select
+import errno
+import pytun
+
+class TunnelServer(object):
+
+    def __init__(self, taddr, tdstaddr, tmask, tmtu, laddr, lport, raddr, rport):
+        self._tun = pytun.TunTapDevice(flags=pytun.IFF_TUN|pytun.IFF_NO_PI)
+        self._tun.addr = taddr
+        self._tun.dstaddr = tdstaddr
+        self._tun.netmask = tmask
+        self._tun.mtu = tmtu
+        self._tun.up()
+        self._sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
+        self._sock.bind((laddr, lport))
+        self._raddr = raddr
+        self._rport = rport
+
+    def run(self):
+        mtu = self._tun.mtu
+        r = [self._tun, self._sock]; w = []; x = []
+        to_tun = ''
+        to_sock = ''
+        while True:
+            try:
+                r, w, x = select.select(r, w, x)
+                if self._tun in r:
+                    to_sock = self._tun.read(mtu)
+                if self._sock in r:
+                    to_tun, addr = self._sock.recvfrom(65535)
+                    if addr[0] != self._raddr or addr[1] != self._rport:
+                        to_tun = '' # drop packet
+                if self._tun in w:
+                    self._tun.write(to_tun)
+                    to_tun = ''
+                if self._sock in w:
+                    self._sock.sendto(to_sock, (self._raddr, self._rport))
+                    to_sock = ''
+                r = []; w = []
+                if to_tun:
+                    w.append(self._tun)
+                else:
+                    r.append(self._sock)
+                if to_sock:
+                    w.append(self._sock)
+                else:
+                    r.append(self._tun)
+            except (select.error, socket.error, pytun.Error), e:
+                if e[0] == errno.EINTR:
+                    continue
+                print >> sys.stderr, str(e)
+                break
+
+def main():
+    parser = optparse.OptionParser()
+    parser.add_option('--tun-addr', dest='taddr',
+            help='set tunnel local address')
+    parser.add_option('--tun-dstaddr', dest='tdstaddr',
+            help='set tunnel destination address')
+    parser.add_option('--tun-netmask', default='255.255.255.0',dest='tmask',
+            help='set tunnel netmask')
+    parser.add_option('--tun-mtu', type='int', default=1500,dest='tmtu',
+            help='set tunnel MTU')
+    parser.add_option('--local-addr', default='0.0.0.0', dest='laddr',
+            help='set local address [%default]')
+    parser.add_option('--local-port', type='int', default=12000, dest='lport',
+            help='set local port [%default]')
+    parser.add_option('--remote-addr', dest='raddr',
+            help='set remote address')
+    parser.add_option('--remote-port', type='int', dest='rport',
+            help='set remote port')
+    opt, args = parser.parse_args()
+    if not (opt.taddr and opt.tdstaddr and opt.raddr and opt.rport):
+        parser.print_help()
+        return 1
+    try:
+        server = TunnelServer(opt.taddr, opt.tdstaddr, opt.tmask, opt.tmtu,
+                opt.laddr, opt.lport, opt.raddr, opt.rport)
+    except (pytun.Error, socket.error), e:
+        print >> sys.stderr, str(e)
+        return 1
+    server.run()
+    return 0
+
+if __name__ == '__main__':
+    sys.exit(main())
+