diff --git a/include/nuttx/net/iob.h b/include/nuttx/net/iob.h
index 0fbe4f6fc1..e747c8bcd9 100644
--- a/include/nuttx/net/iob.h
+++ b/include/nuttx/net/iob.h
@@ -50,10 +50,6 @@
  * Pre-processor Definitions
  ****************************************************************************/
 
-/* IOB flags */
-
-#define IOBFLAGS_MCAST   (1 << 0) /* Multicast packet */
-
 /* IOB helpers */
 
 #define IOB_DATA(p)      (&(p)->io_data[(p)->io_offset])
@@ -69,8 +65,8 @@
  ****************************************************************************/
 
 /* Represents one I/O buffer.  A packet is contained by one or more I/O
- * buffers in a chain.  The io_flags, io_pktlen, io_vtag and io_priv
- * fields are only valid for the I/O buffer at the head of the chain.
+ * buffers in a chain.  Theio_pktlen and io_priv fields are only valid for
+ * the I/O buffer at the head of the chain.
  */
 
 struct iob_s
@@ -81,7 +77,6 @@ struct iob_s
 
   /* Payload */
 
-  uint8_t  io_flags;    /* Flags associated with the I/O buffer */
 #if CONFIG_IOB_BUFSIZE < 256
   uint8_t  io_len;      /* Length of the data in the entry */
   uint8_t  io_offset;   /* Data begins at this offset */
diff --git a/net/iob/iob_alloc.c b/net/iob/iob_alloc.c
index 39c7d5f1cb..630c5368e4 100644
--- a/net/iob/iob_alloc.c
+++ b/net/iob/iob_alloc.c
@@ -93,7 +93,6 @@ FAR struct iob_s *iob_alloc(void)
       /* Put the I/O buffer in a known state */
 
       iob->io_flink  = NULL; /* Not in a chain */
-      iob->io_flags  = 0;    /* Flags associated with the I/O buffer */
       iob->io_len    = 0;    /* Length of the data in the entry */
       iob->io_offset = 0;    /* Offset to the beginning of data */
       iob->io_pktlen = 0;    /* Total length of the packet */
diff --git a/net/iob/iob_clone.c b/net/iob/iob_clone.c
index c44daffc7c..646ba20ae9 100644
--- a/net/iob/iob_clone.c
+++ b/net/iob/iob_clone.c
@@ -95,7 +95,6 @@ int iob_clone(FAR struct iob_s *iob1, FAR struct iob_s *iob2)
 
   /* Copy the header information */
 
-  iob2->io_flags = iob1->io_flags;
   iob2->io_pktlen = iob1->io_pktlen;
   iob2->io_priv = iob1->io_priv;
 
diff --git a/net/iob/iob_concat.c b/net/iob/iob_concat.c
index 9ca09b1d9d..38a32473b5 100644
--- a/net/iob/iob_concat.c
+++ b/net/iob/iob_concat.c
@@ -91,6 +91,5 @@ void iob_concat(FAR struct iob_s *iob1, FAR struct iob_s *iob2)
   */
 
   iob1->io_pktlen += iob2->io_pktlen;
-  iob2->io_flags   = 0;
   iob2->io_priv    = NULL;
 }
diff --git a/net/iob/iob_free.c b/net/iob/iob_free.c
index e92bf19374..431d39695f 100644
--- a/net/iob/iob_free.c
+++ b/net/iob/iob_free.c
@@ -88,7 +88,6 @@ FAR struct iob_s *iob_free(FAR struct iob_s *iob)
     {
       /* Just copy the flags and private information to the next entry. */
 
-      next->io_flags = iob->io_flags;
       next->io_priv  = iob->io_priv;
 
       /* Copy and decrement the total packet length, being careful to
diff --git a/net/iob/iob_test.c b/net/iob/iob_test.c
index 93ed9b2457..360f78d151 100644
--- a/net/iob/iob_test.c
+++ b/net/iob/iob_test.c
@@ -79,7 +79,7 @@ static void dump_chain(struct iob_s *iob)
   int n;
  
   printf("=========================================================\n");
-  printf("pktlen: %d flags: %02x\n", iob->io_pktlen, iob->io_flags);
+  printf("pktlen: %d\n", iob->io_pktlen);
 
   n = 0;
   pktlen = 0;