diff --git a/tools/testing/selftests/drivers/net/README.rst b/tools/testing/selftests/drivers/net/README.rst
index c6bed9a985bc..3fe49bce4f3a 100644
--- a/tools/testing/selftests/drivers/net/README.rst
+++ b/tools/testing/selftests/drivers/net/README.rst
@@ -70,6 +70,15 @@ LOCAL_V4, LOCAL_V6, REMOTE_V4, REMOTE_V6
 
 Local and remote endpoint IP addresses.
 
+Tests reconfigure the device freely, including taking the link down, and
+expect the addresses to work immediately afterwards. IPv6 needs help::
+
+  ip -6 address add 2001:db8:1::1/64 dev eth0 nodad
+  sysctl -w net.ipv6.conf.eth0.keep_addr_on_down=1
+
+Without those the address is flushed when the link goes down, or spends
+a second unusable while waiting for DAD to finish.
+
 LOCAL_PREFIX_V6
 ~~~~~~~~~~~~~~~
 
diff --git a/tools/testing/selftests/drivers/net/lib/py/env.py b/tools/testing/selftests/drivers/net/lib/py/env.py
index 25903f580b40..6262080a8bf4 100644
--- a/tools/testing/selftests/drivers/net/lib/py/env.py
+++ b/tools/testing/selftests/drivers/net/lib/py/env.py
@@ -239,6 +239,25 @@ class NetDrvEpEnv(NetDrvEnvBase):
         if missing:
             raise Exception("Invalid environment, missing configuration:", missing,
                             "Please see tools/testing/selftests/drivers/net/README.rst")
+        if "LOCAL_V6" in self.env:
+            self._check_v6_env()
+
+    def _check_v6_env(self):
+        """Tests bind() to LOCAL_V6 and bounce the link, it must survive both."""
+        ifname, addr = self.env["NETIF"], self.env["LOCAL_V6"]
+
+        def _keep_addr(scope):
+            with open(f"/proc/sys/net/ipv6/conf/{scope}/keep_addr_on_down",
+                      encoding="utf-8") as fp:
+                return int(fp.read())
+
+        # 'all' wins when non-zero, see addrconf_ifdown()
+        if (_keep_addr("all") or _keep_addr(ifname)) <= 0:
+            ksft_pr(f"WARN: net.ipv6.conf.{ifname}.keep_addr_on_down not set")
+
+        dev = ip(f"-6 address show dev {ifname} to {addr}", json=True)
+        if not (dev and dev[0]["addr_info"][0].get("nodad")):
+            ksft_pr(f"WARN: LOCAL_V6 {addr} not configured with nodad")
 
     def resolve_remote_ifc(self):
         v4 = v6 = None