diff --git a/gen/definitions/profile_parcels/service_lan_vpn_interface_ethernet.yaml b/gen/definitions/profile_parcels/service_lan_vpn_interface_ethernet.yaml
index 9aa4b1b40..5969d0bac 100644
--- a/gen/definitions/profile_parcels/service_lan_vpn_interface_ethernet.yaml
+++ b/gen/definitions/profile_parcels/service_lan_vpn_interface_ethernet.yaml
@@ -1,4 +1,5 @@
 ---
+# Manual resource - Modals toBody is manually configured to support sub interfaces.
 name: Service LAN VPN Interface Ethernet
 rest_endpoint: /v1/feature-profile/sdwan/service/%v/lan/vpn/%s/interface/ethernet
 minimum_version: 20.12.0
diff --git a/gen/definitions/profile_parcels/transport_wan_vpn_interface_ethernet.yaml b/gen/definitions/profile_parcels/transport_wan_vpn_interface_ethernet.yaml
index a9c94ff78..73583762a 100644
--- a/gen/definitions/profile_parcels/transport_wan_vpn_interface_ethernet.yaml
+++ b/gen/definitions/profile_parcels/transport_wan_vpn_interface_ethernet.yaml
@@ -1,4 +1,5 @@
 ---
+# Manual resource - Modals toBody is manually configured to support sub interfaces.
 name: Transport WAN VPN Interface Ethernet
 rest_endpoint: /v1/feature-profile/sdwan/transport/%v/wan/vpn/%s/interface/ethernet
 minimum_version: 20.12.0
diff --git a/internal/provider/model_sdwan_service_lan_vpn_interface_ethernet_feature.go b/internal/provider/model_sdwan_service_lan_vpn_interface_ethernet_feature.go
index 2c065af65..a1516c883 100644
--- a/internal/provider/model_sdwan_service_lan_vpn_interface_ethernet_feature.go
+++ b/internal/provider/model_sdwan_service_lan_vpn_interface_ethernet_feature.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"net/url"
 	"strconv"
+	"strings"
 
 	"github.com/CiscoDevNet/terraform-provider-sdwan/internal/provider/helpers"
 	"github.com/hashicorp/terraform-plugin-framework/types"
@@ -232,7 +233,6 @@ func (data ServiceLANVPNInterfaceEthernet) getPath() string {
 
 // End of section. //template:end getPath
 
-// Section below is generated&owned by "gen/generator.go". //template:begin toBody
 func (data ServiceLANVPNInterfaceEthernet) toBody(ctx context.Context) string {
 	body := ""
 	body, _ = sjson.Set(body, "name", data.Name.ValueString())
@@ -1143,7 +1143,7 @@ func (data ServiceLANVPNInterfaceEthernet) toBody(ctx context.Context) string {
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.value", data.InterfaceMtuVariable.ValueString())
 		}
 	} else if data.InterfaceMtu.IsNull() {
-		if true {
+		if !strings.Contains(data.InterfaceName.ValueString(), ".") {
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.optionType", "default")
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.value", 1500)
 		}
@@ -1326,8 +1326,6 @@ func (data ServiceLANVPNInterfaceEthernet) toBody(ctx context.Context) string {
 	return body
 }
 
-// End of section. //template:end toBody
-
 // Section below is generated&owned by "gen/generator.go". //template:begin fromBody
 func (data *ServiceLANVPNInterfaceEthernet) fromBody(ctx context.Context, res gjson.Result) {
 	data.Name = types.StringValue(res.Get("payload.name").String())
diff --git a/internal/provider/model_sdwan_transport_wan_vpn_interface_ethernet_feature.go b/internal/provider/model_sdwan_transport_wan_vpn_interface_ethernet_feature.go
index 820bde268..e1f0652be 100644
--- a/internal/provider/model_sdwan_transport_wan_vpn_interface_ethernet_feature.go
+++ b/internal/provider/model_sdwan_transport_wan_vpn_interface_ethernet_feature.go
@@ -22,6 +22,7 @@ import (
 	"context"
 	"fmt"
 	"net/url"
+	"strings"
 
 	"github.com/CiscoDevNet/terraform-provider-sdwan/internal/provider/helpers"
 	"github.com/hashicorp/terraform-plugin-framework/types"
@@ -298,7 +299,6 @@ func (data TransportWANVPNInterfaceEthernet) getPath() string {
 
 // End of section. //template:end getPath
 
-// Section below is generated&owned by "gen/generator.go". //template:begin toBody
 func (data TransportWANVPNInterfaceEthernet) toBody(ctx context.Context) string {
 	body := ""
 	body, _ = sjson.Set(body, "name", data.Name.ValueString())
@@ -1791,7 +1791,7 @@ func (data TransportWANVPNInterfaceEthernet) toBody(ctx context.Context) string
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.value", data.InterfaceMtuVariable.ValueString())
 		}
 	} else if data.InterfaceMtu.IsNull() {
-		if true {
+		if !strings.Contains(data.InterfaceName.ValueString(), ".") {
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.optionType", "default")
 			body, _ = sjson.Set(body, path+"advanced.intrfMtu.value", 1500)
 		}
@@ -1991,8 +1991,6 @@ func (data TransportWANVPNInterfaceEthernet) toBody(ctx context.Context) string
 	return body
 }
 
-// End of section. //template:end toBody
-
 // Section below is generated&owned by "gen/generator.go". //template:begin fromBody
 func (data *TransportWANVPNInterfaceEthernet) fromBody(ctx context.Context, res gjson.Result) {
 	data.Name = types.StringValue(res.Get("payload.name").String())