@@ -2642,7 +2642,11 @@ test_routes(const struct route_list *rl, const struct tuntap *tt)

         ret = true;

         adapter_up = true;

-        if (rl)

+        /* we do this test only if we have IPv4 routes to install, and if

+         * the tun/tap interface has seen IPv4 ifconfig - because if we

+         * have no IPv4, the check will always fail, failing tun init

+         */

+        if (rl && tt->did_ifconfig_setup)

         {

             struct route_ipv4 *r;

             for (r = rl->routes, len = 0; r; r = r->next, ++len)

@@ -5703,7 +5703,10 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun

             msg(M_FATAL, "ERROR: --dev tun also requires --ifconfig");

         }

-        if (tt->topology == TOP_SUBNET)

+        /* send 0/0/0 to the TAP driver even if we have no IPv4 configured to

+         * ensure it is somehow initialized.

+         */

+        if (!tt->did_ifconfig_setup || tt->topology == TOP_SUBNET)

         {

             in_addr_t ep[3];

             BOOL status;

@@ -5716,12 +5719,19 @@ open_tun(const char *dev, const char *dev_type, const char *dev_node, struct tun

                                      ep, sizeof(ep),

                                      ep, sizeof(ep), &len, NULL);

-            msg(status ? M_INFO : M_FATAL, "Set TAP-Windows TUN subnet mode network/local/netmask = %s/%s/%s [%s]",

-                print_in_addr_t(ep[1], IA_NET_ORDER, &gc),

-                print_in_addr_t(ep[0], IA_NET_ORDER, &gc),

-                print_in_addr_t(ep[2], IA_NET_ORDER, &gc),

-                status ? "SUCCEEDED" : "FAILED");

-

+            if (tt->did_ifconfig_setup)

+            {

+                msg(status ? M_INFO : M_FATAL, "Set TAP-Windows TUN subnet mode network/local/netmask = %s/%s/%s [%s]",

+                    print_in_addr_t(ep[1], IA_NET_ORDER, &gc),

+                    print_in_addr_t(ep[0], IA_NET_ORDER, &gc),

+                    print_in_addr_t(ep[2], IA_NET_ORDER, &gc),

+                    status ? "SUCCEEDED" : "FAILED");

+            }

+            else

+            {

+                msg(status ? M_INFO : M_FATAL, "Set TAP-Windows TUN with fake IPv4 [%s]",

+                    status ? "SUCCEEDED" : "FAILED");

+            }

         }

         else

         {