diff --git a/quic/qbone/bonnet/mock_tun_device.h b/quic/qbone/bonnet/mock_tun_device.h
index d593913..056346c 100644
--- a/quic/qbone/bonnet/mock_tun_device.h
+++ b/quic/qbone/bonnet/mock_tun_device.h
@@ -18,6 +18,8 @@
 
   MOCK_METHOD(bool, Down, (), (override));
 
+  MOCK_METHOD(void, CloseDevice, (), (override));
+
   MOCK_METHOD(int, GetFileDescriptor, (), (const, override));
 };
 
diff --git a/quic/qbone/bonnet/tun_device.cc b/quic/qbone/bonnet/tun_device.cc
index 3ca52e8..86e68d7 100644
--- a/quic/qbone/bonnet/tun_device.cc
+++ b/quic/qbone/bonnet/tun_device.cc
@@ -39,7 +39,7 @@
   if (!persist_) {
     Down();
   }
-  CleanUpFileDescriptor();
+  CloseDevice();
 }
 
 bool TunDevice::Init() {
@@ -63,39 +63,33 @@
 // TODO(pengg): might be better to use netlink socket, once we have a library to
 // use
 bool TunDevice::Up() {
-  if (setup_tun_ && !is_interface_up_) {
-    struct ifreq if_request;
-    memset(&if_request, 0, sizeof(if_request));
-    // copy does not zero-terminate the result string, but we've memset the
-    // entire struct.
-    interface_name_.copy(if_request.ifr_name, IFNAMSIZ);
-    if_request.ifr_flags = IFF_UP;
-
-    is_interface_up_ =
-        NetdeviceIoctl(SIOCSIFFLAGS, reinterpret_cast<void*>(&if_request));
-    return is_interface_up_;
-  } else {
+  if (!setup_tun_) {
     return true;
   }
+  struct ifreq if_request;
+  memset(&if_request, 0, sizeof(if_request));
+  // copy does not zero-terminate the result string, but we've memset the
+  // entire struct.
+  interface_name_.copy(if_request.ifr_name, IFNAMSIZ);
+  if_request.ifr_flags = IFF_UP;
+
+  return NetdeviceIoctl(SIOCSIFFLAGS, reinterpret_cast<void*>(&if_request));
 }
 
 // TODO(pengg): might be better to use netlink socket, once we have a library to
 // use
 bool TunDevice::Down() {
-  if (setup_tun_ && is_interface_up_) {
-    struct ifreq if_request;
-    memset(&if_request, 0, sizeof(if_request));
-    // copy does not zero-terminate the result string, but we've memset the
-    // entire struct.
-    interface_name_.copy(if_request.ifr_name, IFNAMSIZ);
-    if_request.ifr_flags = 0;
-
-    is_interface_up_ =
-        !NetdeviceIoctl(SIOCSIFFLAGS, reinterpret_cast<void*>(&if_request));
-    return !is_interface_up_;
-  } else {
+  if (!setup_tun_) {
     return true;
   }
+  struct ifreq if_request;
+  memset(&if_request, 0, sizeof(if_request));
+  // copy does not zero-terminate the result string, but we've memset the
+  // entire struct.
+  interface_name_.copy(if_request.ifr_name, IFNAMSIZ);
+  if_request.ifr_flags = 0;
+
+  return NetdeviceIoctl(SIOCSIFFLAGS, reinterpret_cast<void*>(&if_request));
 }
 
 int TunDevice::GetFileDescriptor() const {
@@ -103,6 +97,10 @@
 }
 
 bool TunDevice::OpenDevice() {
+  if (file_descriptor_ != kInvalidFd) {
+    CloseDevice();
+  }
+
   struct ifreq if_request;
   memset(&if_request, 0, sizeof(if_request));
   // copy does not zero-terminate the result string, but we've memset the entire
@@ -117,7 +115,7 @@
   if_request.ifr_flags = IFF_TUN | IFF_MULTI_QUEUE | IFF_NO_PI;
 
   // TODO(pengg): port MakeCleanup to quic/platform? This makes the call to
-  // CleanUpFileDescriptor nicer and less error-prone.
+  // CloseDevice nicer and less error-prone.
   // When the device is running with IFF_MULTI_QUEUE set, each call to open will
   // create a queue which can be used to read/write packets from/to the device.
   const std::string tun_device_path =
@@ -125,18 +123,18 @@
   int fd = kernel_.open(tun_device_path.c_str(), O_RDWR);
   if (fd < 0) {
     QUIC_PLOG(WARNING) << "Failed to open " << tun_device_path;
-    CleanUpFileDescriptor();
+    CloseDevice();
     return false;
   }
   file_descriptor_ = fd;
   if (!CheckFeatures(fd)) {
-    CleanUpFileDescriptor();
+    CloseDevice();
     return false;
   }
 
   if (kernel_.ioctl(fd, TUNSETIFF, reinterpret_cast<void*>(&if_request)) != 0) {
     QUIC_PLOG(WARNING) << "Failed to TUNSETIFF on fd(" << fd << ")";
-    CleanUpFileDescriptor();
+    CloseDevice();
     return false;
   }
 
@@ -144,7 +142,7 @@
           fd, TUNSETPERSIST,
           persist_ ? reinterpret_cast<void*>(&if_request) : nullptr) != 0) {
     QUIC_PLOG(WARNING) << "Failed to TUNSETPERSIST on fd(" << fd << ")";
-    CleanUpFileDescriptor();
+    CloseDevice();
     return false;
   }
 
@@ -166,7 +164,7 @@
   if_request.ifr_mtu = mtu_;
 
   if (!NetdeviceIoctl(SIOCSIFMTU, reinterpret_cast<void*>(&if_request))) {
-    CleanUpFileDescriptor();
+    CloseDevice();
     return false;
   }
 
@@ -206,7 +204,7 @@
   return true;
 }
 
-void TunDevice::CleanUpFileDescriptor() {
+void TunDevice::CloseDevice() {
   if (file_descriptor_ != kInvalidFd) {
     kernel_.close(file_descriptor_);
     file_descriptor_ = kInvalidFd;
diff --git a/quic/qbone/bonnet/tun_device.h b/quic/qbone/bonnet/tun_device.h
index bff85f5..129e1d1 100644
--- a/quic/qbone/bonnet/tun_device.h
+++ b/quic/qbone/bonnet/tun_device.h
@@ -49,6 +49,11 @@
   // Marks the interface down to stop receiving packets.
   bool Down() override;
 
+  // Closes the open file descriptor for the TUN device (if one exists).
+  // It is safe to reinitialize and reuse this TunDevice after calling
+  // CloseDevice.
+  void CloseDevice() override;
+
   // Gets the file descriptor that can be used to send/receive packets.
   // This returns -1 when the TUN device is in an invalid state.
   int GetFileDescriptor() const override;
@@ -63,10 +68,6 @@
   // Checks if the required kernel features exists.
   bool CheckFeatures(int tun_device_fd);
 
-  // Closes the opened file descriptor and makes sure the file descriptor
-  // is no longer available from GetFileDescriptor;
-  void CleanUpFileDescriptor();
-
   // Opens a socket and makes netdevice ioctl call
   bool NetdeviceIoctl(int request, void* argp);
 
@@ -76,7 +77,6 @@
   const bool setup_tun_;
   int file_descriptor_;
   KernelInterface& kernel_;
-  bool is_interface_up_ = false;
 };
 
 }  // namespace quic
diff --git a/quic/qbone/bonnet/tun_device_interface.h b/quic/qbone/bonnet/tun_device_interface.h
index e99c547..3c6f962 100644
--- a/quic/qbone/bonnet/tun_device_interface.h
+++ b/quic/qbone/bonnet/tun_device_interface.h
@@ -12,7 +12,7 @@
 // An interface with methods for interacting with a TUN device.
 class TunDeviceInterface {
  public:
-  virtual ~TunDeviceInterface() {}
+  virtual ~TunDeviceInterface() = default;
 
   // Actually creates/reopens and configures the device.
   virtual bool Init() = 0;
@@ -23,6 +23,11 @@
   // Marks the interface down to stop receiving packets.
   virtual bool Down() = 0;
 
+  // Closes the open file descriptor for the TUN device (if one exists).
+  // It is safe to reinitialize and reuse this TunDevice after calling
+  // CloseDevice.
+  virtual void CloseDevice() = 0;
+
   // Gets the file descriptor that can be used to send/receive packets.
   // This returns -1 when the TUN device is in an invalid state.
   virtual int GetFileDescriptor() const = 0;
diff --git a/quic/qbone/bonnet/tun_device_packet_exchanger.cc b/quic/qbone/bonnet/tun_device_packet_exchanger.cc
index 2119671..4783e9c 100644
--- a/quic/qbone/bonnet/tun_device_packet_exchanger.cc
+++ b/quic/qbone/bonnet/tun_device_packet_exchanger.cc
@@ -11,14 +11,12 @@
 namespace quic {
 
 TunDevicePacketExchanger::TunDevicePacketExchanger(
-    int fd,
     size_t mtu,
     KernelInterface* kernel,
     QbonePacketExchanger::Visitor* visitor,
     size_t max_pending_packets,
     StatsInterface* stats)
     : QbonePacketExchanger(visitor, max_pending_packets),
-      fd_(fd),
       mtu_(mtu),
       kernel_(kernel),
       stats_(stats) {}
@@ -78,8 +76,8 @@
   return std::make_unique<QuicData>(read_buffer.release(), result, true);
 }
 
-int TunDevicePacketExchanger::file_descriptor() const {
-  return fd_;
+void TunDevicePacketExchanger::set_file_descriptor(int fd) {
+  fd_ = fd;
 }
 
 const TunDevicePacketExchanger::StatsInterface*
diff --git a/quic/qbone/bonnet/tun_device_packet_exchanger.h b/quic/qbone/bonnet/tun_device_packet_exchanger.h
index 1d28fee..115f5b5 100644
--- a/quic/qbone/bonnet/tun_device_packet_exchanger.h
+++ b/quic/qbone/bonnet/tun_device_packet_exchanger.h
@@ -35,8 +35,6 @@
     ABSL_MUST_USE_RESULT virtual int64_t PacketsWritten() const = 0;
   };
 
-  // |fd| is a open file descriptor on a TUN device that's opened for both read
-  // and write.
   // |mtu| is the mtu of the TUN device.
   // |kernel| is not owned but should out live objects of this class.
   // |visitor| is not owned but should out live objects of this class.
@@ -44,14 +42,13 @@
   // the TUN device become blocked.
   // |stats| is notified about packet read/write statistics. It is not owned,
   // but should outlive objects of this class.
-  TunDevicePacketExchanger(int fd,
-                           size_t mtu,
+  TunDevicePacketExchanger(size_t mtu,
                            KernelInterface* kernel,
                            QbonePacketExchanger::Visitor* visitor,
                            size_t max_pending_packets,
                            StatsInterface* stats);
 
-  ABSL_MUST_USE_RESULT int file_descriptor() const;
+  void set_file_descriptor(int fd);
 
   ABSL_MUST_USE_RESULT const StatsInterface* stats_interface() const;
 
diff --git a/quic/qbone/bonnet/tun_device_packet_exchanger_test.cc b/quic/qbone/bonnet/tun_device_packet_exchanger_test.cc
index 4a00c60..c8f3ff0 100644
--- a/quic/qbone/bonnet/tun_device_packet_exchanger_test.cc
+++ b/quic/qbone/bonnet/tun_device_packet_exchanger_test.cc
@@ -30,14 +30,15 @@
 class TunDevicePacketExchangerTest : public QuicTest {
  protected:
   TunDevicePacketExchangerTest()
-      : exchanger_(kFd,
-                   kMtu,
+      : exchanger_(kMtu,
                    &mock_kernel_,
                    &mock_visitor_,
                    kMaxPendingPackets,
-                   &mock_stats_) {}
+                   &mock_stats_) {
+    exchanger_.set_file_descriptor(kFd);
+  }
 
-  ~TunDevicePacketExchangerTest() override {}
+  ~TunDevicePacketExchangerTest() override = default;
 
   MockKernel mock_kernel_;
   StrictMock<MockVisitor> mock_visitor_;
diff --git a/quic/qbone/bonnet/tun_device_test.cc b/quic/qbone/bonnet/tun_device_test.cc
index 9c216af..6a02f07 100644
--- a/quic/qbone/bonnet/tun_device_test.cc
+++ b/quic/qbone/bonnet/tun_device_test.cc
@@ -139,6 +139,7 @@
   TunDevice tun_device(kDeviceName, 1500, false, true, &mock_kernel_);
   EXPECT_FALSE(tun_device.Init());
   EXPECT_EQ(tun_device.GetFileDescriptor(), -1);
+  ExpectDown(false);
 }
 
 TEST_F(TunDeviceTest, FailToCheckFeature) {
@@ -147,6 +148,7 @@
   TunDevice tun_device(kDeviceName, 1500, false, true, &mock_kernel_);
   EXPECT_FALSE(tun_device.Init());
   EXPECT_EQ(tun_device.GetFileDescriptor(), -1);
+  ExpectDown(false);
 }
 
 TEST_F(TunDeviceTest, TooFewFeature) {
@@ -160,6 +162,7 @@
   TunDevice tun_device(kDeviceName, 1500, false, true, &mock_kernel_);
   EXPECT_FALSE(tun_device.Init());
   EXPECT_EQ(tun_device.GetFileDescriptor(), -1);
+  ExpectDown(false);
 }
 
 TEST_F(TunDeviceTest, FailToSetFlag) {