diff --git a/utils/src/main/java/org/zstack/utils/network/IPv6NetworkUtils.java b/utils/src/main/java/org/zstack/utils/network/IPv6NetworkUtils.java
index 5d41ff8b..bc77a654 100644
--- a/utils/src/main/java/org/zstack/utils/network/IPv6NetworkUtils.java
+++ b/utils/src/main/java/org/zstack/utils/network/IPv6NetworkUtils.java
@@ -209,8 +209,10 @@ public static boolean isIpv6RangeOverlap(String startIp1, String endIp1, String
             IPv6AddressRange range1 = IPv6AddressRange.fromFirstAndLast(s1, e1);
             IPv6AddressRange range2 = IPv6AddressRange.fromFirstAndLast(s2, e2);
             return range1.overlaps(range2);
-        } catch (Exception e) {
-            return true;
+        } catch (IllegalArgumentException e) {
+            logger.warn(String.format("invalid IPv6 range supplied: [%s, %s], [%s, %s]",
+                    startIp1, endIp1, startIp2, endIp2), e);
+            return false;
         }
     }
 
diff --git a/utils/src/test/java/org/zstack/utils/test/TestIPv6NetworkUtilsEdgeCases.java b/utils/src/test/java/org/zstack/utils/test/TestIPv6NetworkUtilsEdgeCases.java
new file mode 100644
index 00000000..f05e1e27
--- /dev/null
+++ b/utils/src/test/java/org/zstack/utils/test/TestIPv6NetworkUtilsEdgeCases.java
@@ -0,0 +1,29 @@
+package org.zstack.utils.test;
+
+import org.junit.Test;
+import org.zstack.utils.network.IPv6NetworkUtils;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+public class TestIPv6NetworkUtilsEdgeCases {
+    @Test
+    public void testRangeOverlap() {
+        assertTrue(IPv6NetworkUtils.isIpv6RangeOverlap(
+                "2001:db8::1", "2001:db8::10",
+                "2001:db8::10", "2001:db8::20"));
+        assertFalse(IPv6NetworkUtils.isIpv6RangeOverlap(
+                "2001:db8::1", "2001:db8::10",
+                "2001:db8::11", "2001:db8::20"));
+    }
+
+    @Test
+    public void testInvalidRangeDoesNotOverlap() {
+        assertFalse(IPv6NetworkUtils.isIpv6RangeOverlap(
+                "2001:db8::10", "2001:db8::2",
+                "2001:db8::1", "2001:db8::20"));
+        assertFalse(IPv6NetworkUtils.isIpv6RangeOverlap(
+                "not-an-ip", "2001:db8::2",
+                "2001:db8::1", "2001:db8::20"));
+    }
+}