diff --git a/ports/mimxrt/boards/MIMXRT1170_EVK/mpconfigboard.h b/ports/mimxrt/boards/MIMXRT1170_EVK/mpconfigboard.h
index 5982326ed2..1154aac830 100644
--- a/ports/mimxrt/boards/MIMXRT1170_EVK/mpconfigboard.h
+++ b/ports/mimxrt/boards/MIMXRT1170_EVK/mpconfigboard.h
@@ -167,9 +167,7 @@
     { IOMUXC_GPIO_AD_33_ENET_MDIO, 0, 0x06u }, \
     { IOMUXC_GPIO_AD_32_ENET_MDC, 0, 0x06u },
 
-// A second ETH port is present.
-#define ENET_DUAL_PORT         (1)
-// 1G Transceiver Phy Parameters
+// 1G Transceiver Phy Parameters (second ETH port)
 #define ENET_1_PHY_ADDRESS     (1)
 #define ENET_1_PHY             RTL8211F
 #define ENET_1_PHY_OPS         phyrtl8211f_ops
diff --git a/ports/mimxrt/eth.c b/ports/mimxrt/eth.c
index bbca2f6646..308f5407a2 100644
--- a/ports/mimxrt/eth.c
+++ b/ports/mimxrt/eth.c
@@ -31,7 +31,7 @@
 #include "py/mperrno.h"
 #include "ticks.h"
 
-#if defined(IOMUX_TABLE_ENET)
+#if defined(ENET_PHY_ADDRESS) || defined(ENET_1_PHY_ADDRESS)
 
 #include "pin.h"
 #include "shared/netutils/netutils.h"
@@ -75,6 +75,8 @@ typedef struct _iomux_table_t {
     uint32_t configValue;
 } iomux_table_t;
 
+#if defined(ENET_PHY_ADDRESS)
+
 // ETH0 buffers and handles
 static AT_NONCACHEABLE_SECTION_ALIGN(enet_rx_bd_struct_t g_rxBuffDescrip[ENET_RXBD_NUM], ENET_BUFF_ALIGNMENT);
 static AT_NONCACHEABLE_SECTION_ALIGN(enet_tx_bd_struct_t g_txBuffDescrip[ENET_TXBD_NUM], ENET_BUFF_ALIGNMENT);
@@ -111,7 +113,9 @@ static const iomux_table_t iomux_table_enet[] = {
 
 static uint8_t hw_addr[6]; // The MAC address field
 
-#if defined(ENET_DUAL_PORT)
+#endif // defined(ENET_PHY_ADDRESS)
+
+#if defined(ENET_1_PHY_ADDRESS)
 
 // ETH1 buffers and handles
 static AT_NONCACHEABLE_SECTION_ALIGN(enet_rx_bd_struct_t g_rxBuffDescrip_1[ENET_RXBD_NUM], ENET_BUFF_ALIGNMENT);
@@ -148,17 +152,14 @@ static const iomux_table_t iomux_table_enet_1[] = {
 
 static uint8_t hw_addr_1[6]; // The MAC address field
 
-#endif
-
-#if defined(ENET_DUAL_PORT)
+// Define ENET_1 to the appropriate controller for this hardware
 #if defined MIMXRT117x_SERIES
 #define ENET_1 ENET_1G
 #else
 #define ENET_1 ENET2
 #endif
-#else
-#define ENET_1 ENET
-#endif
+
+#endif // defined(ENET_1_PHY_ADDRESS)
 
 #define PHY_AUTONEGO_TIMEOUT_US (5000000)
 #define PHY_SETTLE_TIME_US      (1000)
@@ -357,6 +358,8 @@ static void eth_phy_init(phy_handle_t *phyHandle, phy_config_t *phy_config,
     mp_hal_delay_us(phy_settle_time);
 }
 
+#if defined(ENET_PHY_ADDRESS)
+
 // eth_init: Set up GPIO and the transceiver
 void eth_init_0(eth_t *self, int eth_id, const phy_operations_t *phy_ops, int phy_addr, bool phy_clock) {
     // Configuration values
@@ -411,7 +414,9 @@ void eth_init_0(eth_t *self, int eth_id, const phy_operations_t *phy_ops, int ph
     ENET_ActiveRead(ENET);
 }
 
-#if defined(ENET_DUAL_PORT)
+#endif // defined(ENET_PHY_ADDRESS)
+
+#if defined(ENET_1_PHY_ADDRESS)
 
 // eth_init: Set up GPIO and the transceiver
 void eth_init_1(eth_t *self, int eth_id, const phy_operations_t *phy_ops, int phy_addr, bool phy_clock) {
@@ -474,7 +479,8 @@ void eth_init_1(eth_t *self, int eth_id, const phy_operations_t *phy_ops, int ph
     ENET_ActiveRead(ENET_1);
 }
 
-#endif
+#endif // defined(ENET_1_PHY_ADDRESS)
+
 // Initialize the phy interface
 static int eth_mac_init(eth_t *self) {
     return 0;
@@ -512,14 +518,26 @@ static err_t eth_send_frame_blocking(ENET_Type *base, enet_handle_t *handle, uin
 static err_t eth_netif_output(struct netif *netif, struct pbuf *p) {
     // This function should always be called from a context where PendSV-level IRQs are disabled
     status_t status;
-    ENET_Type *enet = ENET;
-    enet_handle_t *handle = &g_handle;
+    ENET_Type *enet;
+    enet_handle_t *handle;
 
-    #if defined ENET_DUAL_PORT
+    #if defined(ENET_PHY_ADDRESS) && defined(ENET_1_PHY_ADDRESS)
+    // Dual port: select based on netif->state
     if (netif->state == &eth_instance1) {
         enet = ENET_1;
         handle = &g_handle_1;
+    } else {
+        enet = ENET;
+        handle = &g_handle;
     }
+    #elif defined(ENET_1_PHY_ADDRESS)
+    // Only ENET_1 available
+    enet = ENET_1;
+    handle = &g_handle_1;
+    #else
+    // Only ENET available
+    enet = ENET;
+    handle = &g_handle;
     #endif
 
     eth_trace(netif->state, (size_t)-1, p, NETUTILS_TRACE_IS_TX | NETUTILS_TRACE_NEWLINE);
@@ -562,15 +580,18 @@ static void eth_lwip_init(eth_t *self) {
     ip_addr_t ipconfig[4];
 
     self->netif.hwaddr_len = 6;
+    #if defined(ENET_PHY_ADDRESS)
     if (self == &eth_instance0) {
         memcpy(self->netif.hwaddr, hw_addr, 6);
         IP4_ADDR(&ipconfig[0], 192, 168, 0, 2);
-    #if defined ENET_DUAL_PORT
-    } else {
+    }
+    #endif
+    #if defined(ENET_1_PHY_ADDRESS)
+    if (self == &eth_instance1) {
         memcpy(self->netif.hwaddr, hw_addr_1, 6);
         IP4_ADDR(&ipconfig[0], 192, 168, 0, 3);
-    #endif
     }
+    #endif
     IP4_ADDR(&ipconfig[1], 255, 255, 255, 0);
     IP4_ADDR(&ipconfig[2], 192, 168, 0, 1);
     IP4_ADDR(&ipconfig[3], 8, 8, 8, 8);
@@ -578,7 +599,11 @@ static void eth_lwip_init(eth_t *self) {
     MICROPY_PY_LWIP_ENTER
 
     n->name[0] = 'e';
+    #if defined(ENET_PHY_ADDRESS)
     n->name[1] = (self == &eth_instance0 ? '0' : '1');
+    #else
+    n->name[1] = '1';
+    #endif
     netif_add(n, &ipconfig[0], &ipconfig[1], &ipconfig[2], self, eth_netif_init, ethernet_input);
     netif_set_hostname(n, mod_network_hostname_data);
     netif_set_default(n);
@@ -620,8 +645,10 @@ int eth_link_status(eth_t *self) {
         }
     } else {
         bool link;
-        #if defined ENET_DUAL_PORT
+        #if defined(ENET_PHY_ADDRESS) && defined(ENET_1_PHY_ADDRESS)
         PHY_GetLinkStatus(self == &eth_instance0 ? &phyHandle : &phyHandle_1, &link);
+        #elif defined(ENET_1_PHY_ADDRESS)
+        PHY_GetLinkStatus(&phyHandle_1, &link);
         #else
         PHY_GetLinkStatus(&phyHandle, &link);
         #endif
@@ -654,10 +681,12 @@ int eth_stop(eth_t *self) {
 }
 
 void eth_low_power_mode(eth_t *self, bool enable) {
-    #if defined ENET_DUAL_PORT
+    #if defined(ENET_PHY_ADDRESS) && defined(ENET_1_PHY_ADDRESS)
     ENET_EnableSleepMode(self == &eth_instance0 ? ENET : ENET_1, enable);
+    #elif defined(ENET_1_PHY_ADDRESS)
+    ENET_EnableSleepMode(ENET_1, enable);
     #else
     ENET_EnableSleepMode(ENET, enable);
     #endif
 }
-#endif // defined(IOMUX_TABLE_ENET)
+#endif // defined(ENET_PHY_ADDRESS) || defined(ENET_1_PHY_ADDRESS)
diff --git a/ports/mimxrt/eth.h b/ports/mimxrt/eth.h
index 0d9ed599bc..4c87d1b517 100644
--- a/ports/mimxrt/eth.h
+++ b/ports/mimxrt/eth.h
@@ -28,11 +28,14 @@
 #define MICROPY_INCLUDED_MIMXRT_ETH_H
 
 typedef struct _eth_t eth_t;
-extern eth_t eth_instance0;
-extern eth_t eth_instance1;
-void eth_init_0(eth_t *self, int mac_idx, const phy_operations_t *phy_ops, int phy_addr, bool phy_clock);
 
-#if defined(ENET_DUAL_PORT)
+#if defined(ENET_PHY_ADDRESS)
+extern eth_t eth_instance0;
+void eth_init_0(eth_t *self, int mac_idx, const phy_operations_t *phy_ops, int phy_addr, bool phy_clock);
+#endif
+
+#if defined(ENET_1_PHY_ADDRESS)
+extern eth_t eth_instance1;
 void eth_init_1(eth_t *self, int mac_idx, const phy_operations_t *phy_ops, int phy_addr, bool phy_clock);
 #endif
 
diff --git a/ports/mimxrt/mpconfigport.h b/ports/mimxrt/mpconfigport.h
index 45316b904b..52289549d7 100644
--- a/ports/mimxrt/mpconfigport.h
+++ b/ports/mimxrt/mpconfigport.h
@@ -179,7 +179,7 @@ uint32_t trng_random_u32(void);
 
 // Hooks to add builtins
 
-#if defined(IOMUX_TABLE_ENET)
+#if defined(ENET_PHY_ADDRESS) || defined(ENET_1_PHY_ADDRESS)
 extern const struct _mp_obj_type_t network_lan_type;
 #define MICROPY_HW_NIC_ETH                  { MP_ROM_QSTR(MP_QSTR_LAN), MP_ROM_PTR(&network_lan_type) },
 #else
diff --git a/ports/mimxrt/network_lan.c b/ports/mimxrt/network_lan.c
index 46f1bfa186..b020d53e6e 100644
--- a/ports/mimxrt/network_lan.c
+++ b/ports/mimxrt/network_lan.c
@@ -28,7 +28,7 @@
 #include "py/mphal.h"
 #include "extmod/modnetwork.h"
 
-#if defined(IOMUX_TABLE_ENET)
+#if defined(ENET_PHY_ADDRESS) || defined(ENET_1_PHY_ADDRESS)
 
 #include "fsl_phy.h"
 #include "eth.h"
@@ -55,9 +55,13 @@ typedef struct _network_lan_obj_t {
     eth_t *eth;
 } network_lan_obj_t;
 
+// Forward declaration of the type
+extern const mp_obj_type_t network_lan_type;
 
+#if defined(ENET_PHY_ADDRESS)
 static const network_lan_obj_t network_lan_eth0 = { { &network_lan_type }, &eth_instance0 };
-#if defined(ENET_DUAL_PORT)
+#endif
+#if defined(ENET_1_PHY_ADDRESS)
 static const network_lan_obj_t network_lan_eth1 = { { &network_lan_type }, &eth_instance1 };
 #endif
 
@@ -65,8 +69,19 @@ static void network_lan_print(const mp_print_t *print, mp_obj_t self_in, mp_prin
     network_lan_obj_t *self = MP_OBJ_TO_PTR(self_in);
     struct netif *netif = eth_netif(self->eth);
     int status = eth_link_status(self->eth);
+    int eth_id = 0;
+    #if defined(ENET_PHY_ADDRESS)
+    if (self->eth == &eth_instance0) {
+        eth_id = 0;
+    }
+    #endif
+    #if defined(ENET_1_PHY_ADDRESS)
+    if (self->eth == &eth_instance1) {
+        eth_id = 1;
+    }
+    #endif
     mp_printf(print, "<ETH%d status=%u ip=%u.%u.%u.%u>",
-        self->eth == &eth_instance0 ? 0 : 1,
+        eth_id,
         status,
         netif->ip_addr.addr & 0xff,
         netif->ip_addr.addr >> 8 & 0xff,
@@ -77,8 +92,18 @@ static void network_lan_print(const mp_print_t *print, mp_obj_t self_in, mp_prin
 
 static mp_obj_t network_lan_make_new(const mp_obj_type_t *type, size_t n_args, size_t n_kw, const mp_obj_t *all_args) {
     enum { ARG_id, ARG_phy_type, ARG_phy_addr, ARG_ref_clk_mode};
+
+    // Default to port 0 if ENET available, else port 1 if only ENET_1 available
+    #if defined(ENET_PHY_ADDRESS)
+    #define DEFAULT_ETH_ID 0
+    #elif defined(ENET_1_PHY_ADDRESS)
+    #define DEFAULT_ETH_ID 1
+    #else
+    #error "No Ethernet PHY configured"
+    #endif
+
     static const mp_arg_t allowed_args[] = {
-        { MP_QSTR_id, MP_ARG_INT, {.u_int = 0} },
+        { MP_QSTR_id, MP_ARG_INT, {.u_int = DEFAULT_ETH_ID} },
         { MP_QSTR_phy_type, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_phy_addr, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
         { MP_QSTR_ref_clk_mode, MP_ARG_KW_ONLY | MP_ARG_INT, {.u_int = -1} },
@@ -92,18 +117,21 @@ static mp_obj_t network_lan_make_new(const mp_obj_type_t *type, size_t n_args, s
     bool phy_clock;
 
     int mac_id = args[ARG_id].u_int;
-    // set default
+    // set default based on which interface is being used
+    #if defined(ENET_PHY_ADDRESS)
     if (mac_id == 0) {
         phy_ops = &ENET_PHY_OPS;
         phy_addr = ENET_PHY_ADDRESS;
         phy_clock = ENET_TX_CLK_OUTPUT;
-    #if defined(ENET_DUAL_PORT)
-    } else {
+    }
+    #endif
+    #if defined(ENET_1_PHY_ADDRESS)
+    if (mac_id == 1) {
         phy_ops = &ENET_1_PHY_OPS;
         phy_addr = ENET_1_PHY_ADDRESS;
         phy_clock = ENET_1_TX_CLK_OUTPUT;
-    #endif
     }
+    #endif
 
     // Select PHY driver
     int phy_type = args[ARG_phy_type].u_int;
@@ -132,17 +160,21 @@ static mp_obj_t network_lan_make_new(const mp_obj_type_t *type, size_t n_args, s
         phy_clock = args[ARG_ref_clk_mode].u_int;
     }
 
-    // Prepare for two ETH interfaces.
-    const network_lan_obj_t *self;
+    // Initialize the appropriate ETH interface
+    const network_lan_obj_t *self = NULL;
+    #if defined(ENET_PHY_ADDRESS)
     if (mac_id == 0) {
         self = &network_lan_eth0;
         eth_init_0(self->eth, MP_HAL_MAC_ETH0, phy_ops, phy_addr, phy_clock);
-    #if defined(ENET_DUAL_PORT)
-    } else if (mac_id == 1) {
+    }
+    #endif
+    #if defined(ENET_1_PHY_ADDRESS)
+    if (mac_id == 1) {
         self = &network_lan_eth1;
         eth_init_1(self->eth, MP_HAL_MAC_ETH1, phy_ops, phy_addr, phy_clock);
+    }
     #endif
-    } else {
+    if (self == NULL) {
         mp_raise_msg_varg(&mp_type_ValueError, MP_ERROR_TEXT("Invalid LAN interface %d"), mac_id);
     }
 
@@ -275,4 +307,4 @@ MP_DEFINE_CONST_OBJ_TYPE(
     );
 
 
-#endif // defined(IOMUX_TABLE_ENET)
+#endif // defined(ENET_PHY_ADDRESS) || defined(ENET_1_PHY_ADDRESS)