diff --git a/staticlibs/testutils/Android.bp b/staticlibs/testutils/Android.bp
index 6d9414f..89aa136 100644
--- a/staticlibs/testutils/Android.bp
+++ b/staticlibs/testutils/Android.bp
@@ -32,6 +32,7 @@
         "libnanohttpd",
         "net-tests-utils-host-device-common",
         "net-utils-device-common",
+        "net-utils-device-common-netlink",
         "modules-utils-build_system",
     ],
 }
diff --git a/staticlibs/testutils/devicetests/com/android/testutils/NetlinkTestUtils.kt b/staticlibs/testutils/devicetests/com/android/testutils/NetlinkTestUtils.kt
new file mode 100644
index 0000000..ccfe710
--- /dev/null
+++ b/staticlibs/testutils/devicetests/com/android/testutils/NetlinkTestUtils.kt
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+@file:JvmName("NetlinkTestUtils")
+
+package com.android.testutils
+
+import com.android.net.module.util.netlink.NetlinkConstants.RTM_DELNEIGH
+import com.android.net.module.util.netlink.NetlinkConstants.RTM_NEWNEIGH
+import libcore.util.HexEncoding
+import libcore.util.HexEncoding.encodeToString
+import java.net.Inet6Address
+import java.net.InetAddress
+
+/**
+ * Make a RTM_NEWNEIGH netlink message.
+ */
+fun makeNewNeighMessage(
+    neighAddr: InetAddress,
+    nudState: Short
+) = makeNeighborMessage(
+        neighAddr = neighAddr,
+        type = RTM_NEWNEIGH,
+        nudState = nudState
+)
+
+/**
+ * Make a RTM_DELNEIGH netlink message.
+ */
+fun makeDelNeighMessage(
+    neighAddr: InetAddress,
+    nudState: Short
+) = makeNeighborMessage(
+        neighAddr = neighAddr,
+        type = RTM_DELNEIGH,
+        nudState = nudState
+)
+
+private fun makeNeighborMessage(
+    neighAddr: InetAddress,
+    type: Short,
+    nudState: Short
+) = HexEncoding.decode(
+    /* ktlint-disable indent */
+    // -- struct nlmsghdr --
+                         // length = 88 or 76:
+    (if (neighAddr is Inet6Address) "58000000" else "4c000000") +
+    type.toLEHex() +     // type
+    "0000" +             // flags
+    "00000000" +         // seqno
+    "00000000" +         // pid (0 == kernel)
+    // struct ndmsg
+                         // family (AF_INET6 or AF_INET)
+    (if (neighAddr is Inet6Address) "0a" else "02") +
+    "00" +               // pad1
+    "0000" +             // pad2
+    "15000000" +         // interface index (21 == wlan0, on test device)
+    nudState.toLEHex() + // NUD state
+    "00" +               // flags
+    "01" +               // type
+    // -- struct nlattr: NDA_DST --
+                         // length = 20 or 8:
+    (if (neighAddr is Inet6Address) "1400" else "0800") +
+    "0100" +             // type (1 == NDA_DST, for neighbor messages)
+                         // IP address:
+    encodeToString(neighAddr.address) +
+    // -- struct nlattr: NDA_LLADDR --
+    "0a00" +             // length = 10
+    "0200" +             // type (2 == NDA_LLADDR, for neighbor messages)
+    "00005e000164" +     // MAC Address (== 00:00:5e:00:01:64)
+    "0000" +             // padding, for 4 byte alignment
+    // -- struct nlattr: NDA_PROBES --
+    "0800" +             // length = 8
+    "0400" +             // type (4 == NDA_PROBES, for neighbor messages)
+    "01000000" +         // number of probes
+    // -- struct nlattr: NDA_CACHEINFO --
+    "1400" +             // length = 20
+    "0300" +             // type (3 == NDA_CACHEINFO, for neighbor messages)
+    "05190000" +         // ndm_used, as "clock ticks ago"
+    "05190000" +         // ndm_confirmed, as "clock ticks ago"
+    "190d0000" +         // ndm_updated, as "clock ticks ago"
+    "00000000",          // ndm_refcnt
+    false /* allowSingleChar */)
+    /* ktlint-enable indent */
+
+/**
+ * Convert a [Short] to a little-endian hex string.
+ */
+private fun Short.toLEHex() = String.format("%04x", java.lang.Short.reverseBytes(this))