diff --git a/libs/libpcf/src/base/repack_design_constraints.h b/libs/libpcf/src/base/repack_design_constraints.h
index 31db9562d..2d8688baf 100644
--- a/libs/libpcf/src/base/repack_design_constraints.h
+++ b/libs/libpcf/src/base/repack_design_constraints.h
@@ -36,7 +36,11 @@ constexpr const char* REPACK_DESIGN_CONSTRAINT_OPEN_NET = "OPEN";
  *******************************************************************/
 class RepackDesignConstraints {
  public: /* Type of design constraints */
-  enum e_design_constraint_type { PIN_ASSIGNMENT, NUM_DESIGN_CONSTRAINT_TYPES };
+  enum e_design_constraint_type {
+    PIN_ASSIGNMENT,
+    NUM_DESIGN_CONSTRAINT_TYPES,
+    IGNORE_NET
+  };
 
  public: /* Types */
   typedef vtr::vector<RepackDesignConstraintId,
diff --git a/libs/libpcf/src/io/read_xml_repack_design_constraints.cpp b/libs/libpcf/src/io/read_xml_repack_design_constraints.cpp
index 008aac3ca..11b848b2c 100644
--- a/libs/libpcf/src/io/read_xml_repack_design_constraints.cpp
+++ b/libs/libpcf/src/io/read_xml_repack_design_constraints.cpp
@@ -11,6 +11,7 @@
 
 /* Headers from vtr util library */
 #include "vtr_assert.h"
+#include "vtr_log.h"
 #include "vtr_time.h"
 
 /* Headers from libopenfpga util library */
@@ -52,6 +53,48 @@ static void read_xml_pin_constraint(
     get_attribute(xml_pin_constraint, "net", loc_data).as_string());
 }
 
+static void read_xml_ignore_net_constraint(
+  pugi::xml_node& xml_pin_constraint, const pugiutil::loc_data& loc_data,
+  RepackDesignConstraints& repack_design_constraints) {
+  /* Create a new design constraint in the storage */
+  RepackDesignConstraintId design_constraint_id =
+    repack_design_constraints.create_design_constraint(
+      RepackDesignConstraints::IGNORE_NET);
+
+  if (false == repack_design_constraints.valid_design_constraint_id(
+                 design_constraint_id)) {
+    archfpga_throw(loc_data.filename_c_str(), loc_data.line(xml_pin_constraint),
+                   "Fail to create design constraint!\n");
+  }
+
+  std::string pin_ctx_to_parse =
+    get_attribute(xml_pin_constraint, "pin", loc_data).as_string();
+  openfpga::StringToken pin_tokenizer(pin_ctx_to_parse);
+  std::vector<std::string> pin_info = pin_tokenizer.split('.');
+  /* Expect two contents, otherwise error out */
+  if (pin_info.size() != 2) {
+    std::string err_msg =
+      std::string("Invalid content '") + pin_ctx_to_parse +
+      std::string("' to skip, expect <pb_type_name>.<pin>\n");
+    VTR_LOG_ERROR(err_msg.c_str());
+    VTR_ASSERT(pin_info.size() == 2);
+  }
+  std::string pb_type_name = pin_info[0];
+  openfpga::PortParser port_parser(pin_info[1]);
+  openfpga::BasicPort curr_port = port_parser.port();
+  if (!curr_port.is_valid()) {
+    std::string err_msg =
+      std::string("Invalid pin definition '") + pin_ctx_to_parse +
+      std::string("', expect <pb_type_name>.<pin_name>[int:int]\n");
+    VTR_LOG_ERROR(err_msg.c_str());
+    VTR_ASSERT(curr_port.is_valid());
+  }
+  repack_design_constraints.set_pb_type(design_constraint_id, pb_type_name);
+  repack_design_constraints.set_pin(design_constraint_id, curr_port);
+  repack_design_constraints.set_net(
+    design_constraint_id,
+    get_attribute(xml_pin_constraint, "name", loc_data).as_string());
+}
 /********************************************************************
  * Parse XML codes about <repack_design_constraints> to an object of
  *RepackDesignConstraints
@@ -80,11 +123,16 @@ RepackDesignConstraints read_xml_repack_design_constraints(
 
     for (pugi::xml_node xml_design_constraint : xml_root.children()) {
       /* Error out if the XML child has an invalid name! */
-      if (xml_design_constraint.name() != std::string("pin_constraint")) {
+      if (xml_design_constraint.name() == std::string("pin_constraint")) {
+        read_xml_pin_constraint(xml_design_constraint, loc_data,
+                                repack_design_constraints);
+      } else if (xml_design_constraint.name() ==
+                 std::string("ignore_net")) {
+        read_xml_ignore_net_constraint(xml_design_constraint, loc_data,
+                                       repack_design_constraints);
+      } else {
         bad_tag(xml_design_constraint, loc_data, xml_root, {"pin_constraint"});
       }
-      read_xml_pin_constraint(xml_design_constraint, loc_data,
-                              repack_design_constraints);
     }
   } catch (pugiutil::XmlError& e) {
     archfpga_throw(design_constraint_fname, e.line(), "%s", e.what());
diff --git a/openfpga/src/repack/repack.cpp b/openfpga/src/repack/repack.cpp
index f80a42a41..b13fda540 100644
--- a/openfpga/src/repack/repack.cpp
+++ b/openfpga/src/repack/repack.cpp
@@ -575,10 +575,12 @@ static void add_lb_router_nets(
     /* Only for global net which should be ignored, cache the sink nodes */
     BasicPort curr_pin(std::string(source_pb_pin->port->name),
                        source_pb_pin->pin_number, source_pb_pin->pin_number);
-    if ((clustering_ctx.clb_nlist.net_is_ignored(cluster_net_id)) &&
+    if (((clustering_ctx.clb_nlist.net_is_ignored(cluster_net_id)) &&
         (clustering_ctx.clb_nlist.net_is_global(cluster_net_id)) &&
         (options.is_pin_ignore_global_nets(std::string(lb_type->pb_type->name),
-                                           curr_pin))) {
+                                           curr_pin))) ||(options.net_is_specified_to_be_ignored(
+          atom_ctx.nlist.net_name(pb_pin_mapped_nets[source_pb_pin]),
+          std::string(lb_type->pb_type->name), curr_pin))) {
       /* Find the net mapped to this pin in clustering results*/
       AtomNetId atom_net_id = pb_pin_mapped_nets[source_pb_pin];
 
diff --git a/openfpga/src/repack/repack_option.cpp b/openfpga/src/repack/repack_option.cpp
index b3a06f60f..af48ae2df 100644
--- a/openfpga/src/repack/repack_option.cpp
+++ b/openfpga/src/repack/repack_option.cpp
@@ -46,6 +46,24 @@ bool RepackOption::is_pin_ignore_global_nets(const std::string& pb_type_name,
   return false;
 }
 
+bool RepackOption::net_is_specified_to_be_ignored(std::string cluster_net_name,
+                                                  std::string pb_type_name,
+                                                  const BasicPort& pin) const {
+  const RepackDesignConstraints& design_constraint = design_constraints();
+  /* If found a constraint, record the net name */
+  for (const RepackDesignConstraintId id_ :
+       design_constraint.design_constraints()) {
+    if (design_constraint.type(id_) == RepackDesignConstraints::IGNORE_NET &&
+        design_constraint.pb_type(id_) == pb_type_name &&
+        design_constraint.net(id_) == cluster_net_name) {
+      if (design_constraint.pin(id_).mergeable(pin) &&
+          design_constraint.pin(id_).contained(pin))
+        return true;
+    }
+  }
+  return false;
+}
+
 bool RepackOption::verbose_output() const { return verbose_output_; }
 
 /******************************************************************************
diff --git a/openfpga/src/repack/repack_option.h b/openfpga/src/repack/repack_option.h
index 24f46633d..f37b6e384 100644
--- a/openfpga/src/repack/repack_option.h
+++ b/openfpga/src/repack/repack_option.h
@@ -26,6 +26,9 @@ class RepackOption {
   bool is_pin_ignore_global_nets(const std::string& pb_type_name,
                                  const BasicPort& pin) const;
   bool verbose_output() const;
+  bool net_is_specified_to_be_ignored(
+    std::string cluster_net_name, std::string pb_type_name,
+    const BasicPort& pin) const;
 
  public: /* Public mutators */
   void set_design_constraints(