diff --git a/net/xenfront.cc b/net/xenfront.cc
index c2f0563876..f2a3bea12f 100644
--- a/net/xenfront.cc
+++ b/net/xenfront.cc
@@ -111,7 +111,7 @@ xenfront_net_device::send(packet _p) {
     // FIXME: negotiate and use scatter/gather
     _p.linearize();
 
-    return _tx_ring.free_idx().then([this, p = std::move(_p), frag] (uint32_t idx) mutable {
+    return _tx_ring.entries.get_index().then([this, p = std::move(_p), frag] (unsigned idx) mutable {
 
         auto req_prod = _tx_ring._sring->req_prod;
 
@@ -152,11 +152,14 @@ xenfront_net_device::send(packet _p) {
 #define rmb() asm volatile("lfence":::"memory");
 #define wmb() asm volatile("":::"memory");
 
-// FIXME: This is totally wrong, just coded so we can gt started with sending
 template <typename T>
-future<uint32_t> front_ring<T>::free_idx() {
-    static uint32_t idx = 0;
-    return make_ready_future<uint32_t>(idx++);
+future<unsigned> front_ring<T>::entries::get_index() {
+    return _ids.pop_eventually();
+}
+
+template <typename T>
+future<> front_ring<T>::entries::free_index(unsigned id) {
+    return _ids.push_eventually(std::move(id));
 }
 
 future<> xenfront_net_device::queue_rx_packet() {
diff --git a/net/xenfront.hh b/net/xenfront.hh
index f43a944f95..04ebb1681c 100644
--- a/net/xenfront.hh
+++ b/net/xenfront.hh
@@ -9,6 +9,7 @@
 #include "net.hh"
 #include "core/sstring.hh"
 #include "core/xen/gntalloc.hh"
+#include "core/queue.hh"
 
 std::unique_ptr<net::device> create_xenfront_net_device(boost::program_options::variables_map opts, bool userspace);
 boost::program_options::options_description get_xenfront_net_options_description();
@@ -71,13 +72,21 @@ template <typename T>
 class front_ring {
 public:
     class entries {
+    protected:
+        queue<unsigned> _ids;
     private:
         std::array<gntref, front_ring<T>::nr_ents> _entries;
         front_ring<T> *_ring;
     public:
-        entries(front_ring<T> *ring) : _ring(ring) {}
+        entries(front_ring<T> *ring) : _ids(front_ring<T>::nr_ents), _ring(ring) {
+            for (unsigned i = 0; i < front_ring<T>::nr_ents; ++i) {
+                _ids.push(std::move(i));
+            }
+        }
         gntref& operator[](std::size_t i) { return _entries[_ring->idx(i)]; }
         friend front_ring;
+        future<unsigned> get_index();
+        future<> free_index(unsigned index);
     };
 protected:
     uint32_t idx(int i) { return i & (nr_ents - 1); }
@@ -92,8 +101,6 @@ public:
         , _sring(new (r.page) sring<T>()) {
     }
 
-
-    future<uint32_t> free_idx();
     entries entries;
 
     sring<T> *_sring;