diff --git a/tests/unit/net/collect-netifs.cpp b/tests/unit/net/collect-netifs.cpp
new file mode 100644
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--- /dev/null
+++ b/tests/unit/net/collect-netifs.cpp
@@ -0,0 +1,64 @@
+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/*
+ * Copyright (c) 2013-2018 Regents of the University of California,
+ *                         Arizona Board of Regents,
+ *                         Colorado State University,
+ *                         University Pierre & Marie Curie, Sorbonne University,
+ *                         Washington University in St. Louis,
+ *                         Beijing Institute of Technology,
+ *                         The University of Memphis.
+ *
+ * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
+ *
+ * ndn-cxx library is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU Lesser General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later version.
+ *
+ * ndn-cxx library is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+ * PARTICULAR PURPOSE.  See the GNU Lesser General Public License for more details.
+ *
+ * You should have received copies of the GNU General Public License and GNU Lesser
+ * General Public License along with ndn-cxx, e.g., in COPYING.md file.  If not, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * See AUTHORS.md for complete list of ndn-cxx authors and contributors.
+ */
+
+#include "collect-netifs.hpp"
+#include "net/network-monitor.hpp"
+
+#include <boost/asio/io_service.hpp>
+
+namespace ndn {
+namespace net {
+namespace tests {
+
+std::vector<shared_ptr<const NetworkInterface>>
+collectNetworkInterfaces(bool allowCached)
+{
+  static std::vector<shared_ptr<const NetworkInterface>> cached;
+  // cached.empty() indicates there's no cached list of netifs.
+  // Although it could also mean a system without any network interface, this situation is rare
+  // because the loopback interface is present on almost all systems.
+
+  if (!allowCached || cached.empty()) {
+    boost::asio::io_service io;
+    NetworkMonitor netmon(io);
+    if ((netmon.getCapabilities() & NetworkMonitor::CAP_ENUM) == 0) {
+      BOOST_THROW_EXCEPTION(NetworkMonitor::Error("NetworkMonitor::CAP_ENUM is unavailable"));
+    }
+
+    netmon.onEnumerationCompleted.connect([&io] { io.stop(); });
+    io.run();
+    io.reset();
+
+    cached = netmon.listNetworkInterfaces();
+  }
+
+  return cached;
+}
+
+} // namespace tests
+} // namespace net
+} // namespace ndn