diff --git a/ironic_inspector/pxe_filter/iptables.py b/ironic_inspector/pxe_filter/iptables.py
index 44ba878c7..90226a95b 100644
--- a/ironic_inspector/pxe_filter/iptables.py
+++ b/ironic_inspector/pxe_filter/iptables.py
@@ -226,9 +226,9 @@ def _ib_mac_to_rmac_mapping(ports):
 
 
 def _get_blacklist(ironic):
-    ports = [port.address for port in
+    ports = [port for port in
              ir_utils.call_with_retries(ironic.port.list, limit=0,
                                         fields=['address', 'extra'])
              if port.address not in node_cache.active_macs()]
     _ib_mac_to_rmac_mapping(ports)
-    return ports
+    return [port.address for port in ports]
diff --git a/ironic_inspector/test/unit/test_iptables.py b/ironic_inspector/test/unit/test_iptables.py
index 4602a94fd..9554fa564 100644
--- a/ironic_inspector/test/unit/test_iptables.py
+++ b/ironic_inspector/test/unit/test_iptables.py
@@ -343,10 +343,11 @@ class TestGetBlacklist(test_base.BaseTest):
         self.mock_ironic = mock.Mock()
 
     def test_active_port(self):
-        self.mock_ironic.port.list.return_value = [
+        mock_ports_list = [
             mock.Mock(address='foo'),
             mock.Mock(address='bar'),
         ]
+        self.mock_ironic.port.list.return_value = mock_ports_list
         self.mock_active_macs.return_value = {'foo'}
 
         ports = iptables._get_blacklist(self.mock_ironic)
@@ -354,16 +355,18 @@ class TestGetBlacklist(test_base.BaseTest):
         self.assertEqual(['bar'], ports)
         self.mock_ironic.port.list.assert_called_once_with(
             limit=0, fields=['address', 'extra'])
-        self.mock__ib_mac_to_rmac_mapping.assert_called_once_with(ports)
+        self.mock__ib_mac_to_rmac_mapping.assert_called_once_with(
+            [mock_ports_list[1]])
 
     @mock.patch('time.sleep', lambda _x: None)
     def test_retry_on_port_list_failure(self):
+        mock_ports_list = [
+            mock.Mock(address='foo'),
+            mock.Mock(address='bar'),
+        ]
         self.mock_ironic.port.list.side_effect = [
             ironic_exc.ConnectionRefused('boom'),
-            [
-                mock.Mock(address='foo'),
-                mock.Mock(address='bar'),
-            ]
+            mock_ports_list
         ]
         self.mock_active_macs.return_value = {'foo'}
 
@@ -372,4 +375,5 @@ class TestGetBlacklist(test_base.BaseTest):
         self.assertEqual(['bar'], ports)
         self.mock_ironic.port.list.assert_called_with(
             limit=0, fields=['address', 'extra'])
-        self.mock__ib_mac_to_rmac_mapping.assert_called_once_with(ports)
+        self.mock__ib_mac_to_rmac_mapping.assert_called_once_with(
+            [mock_ports_list[1]])
diff --git a/releasenotes/notes/fix-pxe-filter-get-blacklist-2dde59d51c1d010f.yaml b/releasenotes/notes/fix-pxe-filter-get-blacklist-2dde59d51c1d010f.yaml
new file mode 100644
index 000000000..ca28a6a7f
--- /dev/null
+++ b/releasenotes/notes/fix-pxe-filter-get-blacklist-2dde59d51c1d010f.yaml
@@ -0,0 +1,6 @@
+---
+fixes:
+  - |
+    Fixes an issue while mapping port InfiniBand MAC
+    address to EthernetOverInfiniBand MAC. Prior to this fix,
+    it will fail to map and raise an exception.