diff --git a/tests/test_node_conn_direct.c b/tests/test_node_conn_direct.c
index 3814cc7c..a5a903a8 100644
--- a/tests/test_node_conn_direct.c
+++ b/tests/test_node_conn_direct.c
@@ -25,6 +25,7 @@
 #include <stdarg.h>
 #include "../lib/platform_compat.h"
 #include "test_utils.h"
+#include "test_net.h"
 #ifndef _WIN32
 #include <unistd.h>
 #endif
@@ -110,7 +111,7 @@ static int update_addresses(int up) {
     if (len < 0 || topo_node_deserialize(&group, wire + sizeof(struct TOPOMSG_HEADER), (size_t)len, &copy, NULL, NULL, NULL, NULL) < 0) return -1;
     struct TOPO_ADDR4* addr = memory_pool_alloc(g_a->topo_groups->v4_addr_pool);
     if (!addr) { topo_node_destroy(g_a->topo_groups, copy); return -1; }
-    *addr = (struct TOPO_ADDR4){ .next = copy->v4_addrs, .addr = {127,0,0,2}, .port = (uint16_t)(pb + up),
+    *addr = (struct TOPO_ADDR4){ .next = copy->v4_addrs, .addr = {127,0,0,2}, .port = (uint16_t)(pb == UINT16_MAX && up ? pb - 1 : pb + up),
                                .protocol = TOPO_PROTO_UDP };
     copy->v4_addrs = addr;
     copy->timestamp += (uint64_t)up + 1;
@@ -351,10 +352,11 @@ static int inject_node(struct UTUN_INSTANCE* inst, uint64_t nid, const uint8_t p
 
 static int setup(void) {
     test_mkdtemp(tdir);
-    int base = 49000 + (getpid() % 10000); pa = base; pb = base + 1;
     snprintf(ca, sizeof(ca), "%s/a.conf", tdir); snprintf(cb, sizeof(cb), "%s/b.conf", tdir);
-    wf(ca, "[global]\ntun_ip=10.97.0.1/24\ntun_ifname=tun95\nkeepalive_timeout=100\nkeepalive_interval=10\n[server: s1]\naddr=127.0.0.1:%d\ntype=public\n[allowed_keys]\nallow_all=1\n", pa);
-    wf(cb, "[global]\ntun_ip=10.97.0.2/24\ntun_ifname=tun94\nkeepalive_timeout=100\nkeepalive_interval=10\n[server: s1]\naddr=127.0.0.1:%d\ntype=public\n[allowed_keys]\nallow_all=1\n", pb);
+    wf(ca, "[global]\ntun_ip=10.97.0.1/24\ntun_ifname=tun95\nkeepalive_timeout=100\nkeepalive_interval=10\n"
+           "[server: s1]\naddr=127.0.0.1:0\ntype=public\n[allowed_keys]\nallow_all=1\n");
+    wf(cb, "[global]\ntun_ip=10.97.0.2/24\ntun_ifname=tun94\nkeepalive_timeout=100\nkeepalive_interval=10\n"
+           "[server: s1]\naddr=127.0.0.1:0\ntype=public\n[allowed_keys]\nallow_all=1\n");
     config_ensure_keys_and_node_id(ca); config_ensure_keys_and_node_id(cb);
     return 0;
 }
@@ -367,6 +369,8 @@ int main(void) {
     ua = uasync_create();
     g_a = utun_instance_create(ua, ca); g_b = utun_instance_create(ua, cb);
     if (!g_a || !g_b) { g_result = 2; goto done; }
+    pa = ss_get_port(&test_etcp_bound_socket(g_a, "s1")->local_addr);
+    pb = ss_get_port(&test_etcp_bound_socket(g_b, "s1")->local_addr);
     nid_b = g_b->node_id; memcpy(pubkey_b, g_b->my_keys.public_key, SC_PUBKEY_SIZE);
     nid_a = g_a->node_id; memcpy(pubkey_a, g_a->my_keys.public_key, SC_PUBKEY_SIZE);
     fprintf(stderr, "A: 0x%016llx port=%d  B: 0x%016llx port=%d\n",