diff --git a/helper/lfid/abstract-fib.hpp b/helper/lfid/abstract-fib.hpp
new file mode 100644
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+++ b/helper/lfid/abstract-fib.hpp
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+/* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
+/**
+ * Copyright (c) 2019 Klaus Schneider, The University of Arizona
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation;
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ *
+ * Author: Klaus Schneider <klaus@cs.arizona.edu>
+ */
+
+#ifndef LFID_ABS_FIB_H
+#define LFID_ABS_FIB_H
+
+#include <set>
+#include <unordered_map>
+
+#include "ns3/abort.h"
+#include "ns3/ndnSIM/helper/lfid/fib-nexthop.hpp"
+#include "ns3/ptr.h"
+
+namespace ns3 {
+namespace ndn {
+
+class GlobalRouter;
+
+/**
+ * An abstract, lightweight representation of the FIB.
+ */
+class AbstractFib {
+public:
+  using AllNodeFib = std::unordered_map<int, AbstractFib>;
+
+  /**
+   * @param own The GlobalRouter object representing the current router
+   * @param numNodes The total number of nodes in the network
+   */
+  AbstractFib(const Ptr<GlobalRouter> own, int numNodes);
+
+public:
+  // Getters:
+  /**
+   * @return Return set of nexthops per destination
+   */
+  const std::set<FibNextHop>&
+  getNexthops(int dstId) const;
+
+  /**
+   * @return Return set of upward nexthops per destination
+   */
+  const std::set<FibNextHop>&
+  getUpwardNexthops(int dstId) const;
+
+  /**
+   * Make sure that FIB is consistent (each destination has at least one downward nexthop)
+   */
+  void
+  checkFib() const;
+
+  /**
+   * @return Return number nexthops per destination
+   * @pre Also assure that the destination is not equal to the current nodeId.
+   */
+  int
+  numEnabledNhPerDst(int dstId) const
+  {
+    NS_ABORT_UNLESS(dstId != nodeId);
+    return static_cast<int>(getNexthops(dstId).size());
+  }
+
+  int
+  getNodeId() const
+  {
+    return nodeId;
+  }
+
+  Ptr<GlobalRouter>
+  getGR() const;
+
+  std::string
+  getName() const
+  {
+    return nodeName;
+  }
+
+  int
+  getDegree() const
+  {
+    return nodeDegree;
+  }
+
+  int
+  getNumDsts() const
+  {
+    return static_cast<int>(perDstFib.size());
+  }
+
+  bool
+  contains(int dstId) const
+  {
+    return perDstFib.count(dstId) > 0;
+  }
+
+  // Functions for range-based loop:
+  auto
+  begin() const
+  {
+    return perDstFib.cbegin();
+  }
+
+  auto
+  end() const
+  {
+    return perDstFib.cend();
+  }
+
+  // Setters:
+  void
+  insert(int dstId, const FibNextHop& nh);
+
+  size_t
+  erase(int dstId, int nhId);
+
+private:
+  void
+  checkInputs();
+
+  void
+  createEmptyFib();
+
+private:
+  const int nodeId;           // Own node id
+  const std::string nodeName; // Own node name
+  const int numberOfNodes;
+  const int nodeDegree;
+  const Ptr<GlobalRouter> ownRouter;
+
+  int upwardCounter;
+  int totalNhCounter;
+
+  // DstId -> set<FibNextHop>
+  std::unordered_map<int, std::set<FibNextHop>> perDstFib;
+  std::unordered_map<int, std::set<FibNextHop>> upwardPerDstFib;
+
+  friend std::ostream&
+  operator<<(std::ostream&, const AbstractFib& fib);
+};
+
+std::ostream&
+operator<<(std::ostream& os, const AbstractFib& fib);
+
+} // namespace ndn
+} // namespace ns-3
+
+#endif // LFID_ABS_FIB_H