diff --git a/arch/renesas/src/rx65n/rx65n_eth.c b/arch/renesas/src/rx65n/rx65n_eth.c
index 235d817fb0f..10cc9c1602c 100644
--- a/arch/renesas/src/rx65n/rx65n_eth.c
+++ b/arch/renesas/src/rx65n/rx65n_eth.c
@@ -526,9 +526,6 @@ static int  rx65n_phyinit(FAR struct rx65n_ethmac_s *priv);
 static int  rx65n_ethreset(FAR struct rx65n_ethmac_s *priv);
 static int  rx65n_macconfig(FAR struct rx65n_ethmac_s *priv);
 static void rx65n_macaddress(FAR struct rx65n_ethmac_s *priv);
-#ifdef CONFIG_NET_ICMPv6
-static void rx65n_ipv6multicast(FAR struct rx65n_ethmac_s *priv);
-#endif
 static int  rx65n_ethconfig(FAR struct rx65n_ethmac_s *priv);
 
 static void rx65n_phy_preamble (void);
@@ -2388,51 +2385,6 @@ static int rx65n_txavail(struct net_driver_s *dev)
   return OK;
 }
 
-/****************************************************************************
- * Function: rx65n_calcethcrc
- *
- * Description:
- *   Function to calculate the CRC used by RX65N to check an ethernet frame
- *
- * Input Parameters:
- *   data   - the data to be checked
- *   length - length of the data
- *
- * Returned Value:
- *   None
- *
- * Assumptions:
- *
- ****************************************************************************/
-
-#if defined(CONFIG_NET_MCASTGROUP) || defined(CONFIG_NET_ICMPv6)
-static uint32_t rx65n_calcethcrc(const uint8_t *data, size_t length)
-{
-  uint32_t crc = 0xffffffff;
-  size_t i;
-  int j;
-
-  for (i = 0; i < length; i++)
-    {
-      for (j = 0; j < 8; j++)
-        {
-          if (((crc >> 31) ^ (data[i] >> j)) & 0x01)
-            {
-              /* x^26+x^23+x^22+x^16+x^12+x^11+x^10+x^8+x^7+x^5+x^4+x^2+x+1 */
-
-              crc = (crc << 1) ^ 0x04c11db7;
-            }
-          else
-            {
-              crc = crc << 1;
-            }
-        }
-    }
-
-  return ~crc;
-}
-#endif
-
 /****************************************************************************
  * Function: rx65n_addmac
  *
@@ -2454,20 +2406,9 @@ static uint32_t rx65n_calcethcrc(const uint8_t *data, size_t length)
 #if defined(CONFIG_NET_MCASTGROUP) || defined(CONFIG_NET_ICMPv6)
 static int rx65n_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 {
-  uint32_t regval;
-  uint32_t crc;
-  uint32_t hashindex;
-  uint32_t temp;
-  uint32_t registeraddress;
-  regval = 0;
-
   ninfo("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
         mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
-    crc = rx65n_calcethcrc(mac, 6);
-
-  hashindex = (crc >> 26) & 0x3f;
-
   /* RX65N do not support add on mac multi cast feature because related
    * hash table mac multi cast register is not supported in RX65N.
    */
@@ -2498,20 +2439,9 @@ static int rx65n_addmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 #ifdef CONFIG_NET_MCASTGROUP
 static int rx65n_rmmac(struct net_driver_s *dev, FAR const uint8_t *mac)
 {
-  uint32_t crc;
-  uint32_t hashindex;
-  uint32_t temp;
-  uint32_t registeraddress;
-
   ninfo("MAC: %02x:%02x:%02x:%02x:%02x:%02x\n",
         mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
 
-  /* Remove the MAC address to the hardware multicast hash table */
-
-  crc = rx65n_calcethcrc(mac, 6);
-
-  hashindex = (crc >> 26) & 0x3f;
-
   /* RX65N do not support add on mac multi cast feature because related
    * hash table multi cast mac register not available. This function is
    * not need to implement.
@@ -3784,15 +3714,6 @@ static int rx65n_macconfig(FAR struct rx65n_ethmac_s *priv)
 
   rx65n_macaddress(priv);
 
- #ifdef CONFIG_NET_ICMPv6
-  /* Set up the IPv6 multicast address */
-
-  /* Not supported So commented */
-
-  /* rx65n_ipv6multicast(priv); */
-
- #endif
-
   return OK;
 }
 
@@ -3843,80 +3764,6 @@ static void rx65n_macaddress(FAR struct rx65n_ethmac_s *priv)
   rx65n_putreg(regval, RX65N_ETH_MALR);
 }
 
-/****************************************************************************
- * Function: rx65n_ipv6multicast
- *
- * Description:
- *   Configure the IPv6 multicast MAC address.
- *
- * Input Parameters:
- *   priv - A reference to the private driver state structure
- *
- * Returned Value:
- *   OK on success; Negated errno on failure.
- *
- * Assumptions:
- *
- ****************************************************************************/
-
-#ifdef CONFIG_NET_ICMPv6
-static void rx65n_ipv6multicast(FAR struct rx65n_ethmac_s *priv)
-{
-  struct net_driver_s *dev;
-  uint16_t tmp16;
-  uint8_t mac[6];
-
-  /* For ICMPv6, we need to add the IPv6 multicast address
-   *
-   * For IPv6 multicast addresses, the Ethernet MAC is derived by
-   * the four low-order octets OR'ed with the MAC 33:33:00:00:00:00,
-   * so for example the IPv6 address FF02:DEAD:BEEF::1:3 would map
-   * to the Ethernet MAC address 33:33:00:01:00:03.
-   *
-   * NOTES:  This appears correct for the ICMPv6 Router Solicitation
-   * Message, but the ICMPv6 Neighbor Solicitation message seems to
-   * use 33:33:ff:01:00:03.
-   */
-
-  mac[0] = 0x33;
-  mac[1] = 0x33;
-
-  dev    = &priv->dev;
-  tmp16  = dev->d_ipv6addr[6];
-  mac[2] = 0xff;
-  mac[3] = tmp16 >> 8;
-
-  tmp16  = dev->d_ipv6addr[7];
-  mac[4] = tmp16 & 0xff;
-  mac[5] = tmp16 >> 8;
-
-  ninfo("IPv6 Multicast: %02x:%02x:%02x:%02x:%02x:%02x\n",
-        mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
-
-  (void)rx65n_addmac(dev, mac);
-
-#ifdef CONFIG_NET_ICMPv6_AUTOCONF
-  /* Add the IPv6 all link-local nodes Ethernet address.  This is the
-   * address that we expect to receive ICMPv6 Router Advertisement
-   * packets.
-   */
-
-  (void)rx65n_addmac(dev, g_ipv6_ethallnodes.ether_addr_octet);
-
-#endif /* CONFIG_NET_ICMPv6_AUTOCONF */
-#ifdef CONFIG_NET_ICMPv6_ROUTER
-  /* Add the IPv6 all link-local routers Ethernet address.  This is the
-   * address that we expect to receive ICMPv6 Router Solicitation
-   * packets.
-   */
-
-  (void)rx65n_addmac(dev, g_ipv6_ethallrouters.ether_addr_octet);
-
-#endif /* CONFIG_NET_ICMPv6_ROUTER */
-}
-
-#endif /* CONFIG_NET_ICMPv6 */
-
 /****************************************************************************
  * Function: rx65n_ethconfig
  *