diff --git a/.github/lexicon.txt b/.github/lexicon.txt
index 98538a49fe..06dcb864aa 100644
--- a/.github/lexicon.txt
+++ b/.github/lexicon.txt
@@ -181,6 +181,7 @@ dw
 dword
 dzpq
 eagain
+eapplicationprocesscustomframehook
 earpcachehit
 earpcachemiss
 earptimerevent
diff --git a/FreeRTOS_IP.c b/FreeRTOS_IP.c
index 27888162c8..4246252217 100644
--- a/FreeRTOS_IP.c
+++ b/FreeRTOS_IP.c
@@ -191,6 +191,21 @@ static void prvIPTask( void * pvParameters );
  */
 static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetworkBuffer );
 
+#if ( ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES != 0 )
+
+/*
+ * The stack will call this user hook for all Ethernet frames that it
+ * does not support, i.e. other than IPv4, IPv6 and ARP ( for the moment )
+ * If this hook returns eReleaseBuffer or eProcessBuffer, the stack will
+ * release and reuse the network buffer.  If this hook returns
+ * eReturnEthernetFrame, that means user code has reused the network buffer
+ * to generate a response and the stack will send that response out.
+ * If this hook returns eFrameConsumed, the user code has ownership of the
+ * network buffer and has to release it when it’s done.
+ */
+    extern eFrameProcessingResult_t eApplicationProcessCustomFrameHook( NetworkBufferDescriptor_t * const pxNetworkBuffer );
+#endif /* ( ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES != 0 ) */
+
 /*
  * Process incoming IP packets.
  */
@@ -1727,8 +1742,13 @@ static void prvProcessEthernetPacket( NetworkBufferDescriptor_t * const pxNetwor
                     break;
 
                 default:
-                    /* No other packet types are handled.  Nothing to do. */
-                    eReturned = eReleaseBuffer;
+                    #if ( ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES != 0 )
+                        /* Custom frame handler. */
+                        eReturned = eApplicationProcessCustomFrameHook( pxNetworkBuffer );
+                    #else
+                        /* No other packet types are handled.  Nothing to do. */
+                        eReturned = eReleaseBuffer;
+                    #endif
                     break;
             }
         }
diff --git a/include/FreeRTOSIPConfigDefaults.h b/include/FreeRTOSIPConfigDefaults.h
index dcbabb2159..514f9f6a54 100644
--- a/include/FreeRTOSIPConfigDefaults.h
+++ b/include/FreeRTOSIPConfigDefaults.h
@@ -633,4 +633,12 @@
     #define ipconfigSELECT_USES_NOTIFY    0
 #endif
 
+/* Set to 1 if you plan on processing custom Ethernet protocols or protocols
+ * that are not yet supported by the FreeRTOS+TCP stack. If set to 1,
+ * the user must define eFrameProcessingResult_t eApplicationProcessCustomFrameHook( NetworkBufferDescriptor_t * const pxNetworkBuffer )
+ * which will be called by the stack for any frame with an unsupported EtherType. */
+#ifndef ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES
+    #define ipconfigPROCESS_CUSTOM_ETHERNET_FRAMES    0
+#endif
+
 #endif /* FREERTOS_DEFAULT_IP_CONFIG_H */