diff --git a/hbd/client/connectivity.py b/hbd/client/connectivity.py
index 1250213..4af186b 100644
--- a/hbd/client/connectivity.py
+++ b/hbd/client/connectivity.py
@@ -165,7 +165,9 @@ class Connectivity:
             key = (addr, gw)
         st.addr, st.gateway = addr, gw
         self._last_key[fam] = key
-        if due and fam not in self._ping_disabled:
+        if fam in self._ping_disabled:
+            st.present = None          # cannot probe: unknown, never absent, while a route exists
+        elif due:
             await self._tier2(fam, st, now)
 
     async def _tier2(self, fam: str, st: FamilyState, now: float) -> None:
diff --git a/tests/test_connectivity.py b/tests/test_connectivity.py
index 60d2237..9af80a8 100644
--- a/tests/test_connectivity.py
+++ b/tests/test_connectivity.py
@@ -156,3 +156,18 @@ def test_from_config():
     assert c.probes["ipv4"] == "9.9.9.9"
     assert c.probes["ipv6"] == "2606:4700:4700::1111"
     assert c.probe_interval == 30.0
+
+
+def test_ping_less_family_stays_unknown_after_route_returns():
+    net = Net()
+    net.rtt["ipv4"] = "unavailable"
+    c = make(net)
+    refresh(c)
+    assert "p4" not in c.flags()
+    net.addr["ipv4"] = None
+    refresh(c)
+    assert c.flags()["p4"] is False       # no route is definitive
+    net.addr["ipv4"] = "192.0.2.5"
+    refresh(c)
+    assert "p4" not in c.flags()
+    assert net.pings.count("ipv4") == 1   # missing binary is not retried