I solved my need.
I get the bytes from the EEPROM as well.
#define MY_IP_ADDRESS_B0 EEPROM.read(xxxx)
....
#define MY_IP_ADDRESS_B3 EEPROM.read(yyyy)

Then I define the address of the gateway like this:
#define MY_IP_ADDRESS ((uint32_t)(MY_IP_ADDRESS_B3) << 24) | ((uint32_t)(MY_IP_ADDRESS_B2) << 16) | ((uint32_t)(MY_IP_ADDRESS_B1) << | (uint32_t)(MY_IP_ADDRESS_B0)

This applies to the other addresses required for the operation of an MQTT gateway.
Hopefully this sharing is useful.
Thank you

The 2.2.0-rc.1 version in development seems to solve the problem.
See also the message : https://forum.mysensors.org/topic/6684/serial-gateway-restarting/30
Can you explain the change in the new version?
Thank you.

I tested the solution proposed above.
It works very well.
I can send to the controller the subscription topic of the gateway, its IP address, etc. during the presentation phase of the gateway.
Thanks again.

Thank you for your very clear answer.
I will test by getting a MOSFET.
Have a good day.

1. Yes, there is of course the RJ45 plug on the shield which fits directly by the arduino UNO. The only indications are HanRun HR911105A 15/10.
2. What has changed is that I have always used NRF24 +. The gateway that I use in operation at home is also in version MySensors 2.3.1 with NRF24+
3. I use the basic sketch on the site :

#define MY_DEBUG
#define MY_TRANSPORT_WAIT_READY_MS 10000
#define MY_RADIO_RFM69
#define MY_RF69_SPI_CS 9
#define MY_GATEWAY_W5100
#define MY_GATEWAY_MQTT_CLIENT
#define MY_MQTT_PUBLISH_TOPIC_PREFIX "mhs-pub-1"
#define MY_MQTT_SUBSCRIBE_TOPIC_PREFIX "mhs-sub-1"
#define MY_MQTT_CLIENT_ID "MHS_GW_02"
#define MY_MQTT_USER "xxxxxx"
#define MY_MQTT_PASSWORD "yyyyyyyy"

#define MY_IP_ADDRESS 12,9,0,101
#define MY_IP_GATEWAY_ADDRESS 12,9,0,1
#define MY_IP_SUBNET_ADDRESS 255,255,255,0
#define MY_CONTROLLER_IP_ADDRESS 12,9,0,8
#define MY_PORT 1883
#define MY_MAC_ADDRESS 0xDE, 0xAD, 0xBE, 0xEF, 0xFE, 0xED

#define MY_DEFAULT_LED_BLINK_PERIOD 300

#include <SPI.h>
#include <Ethernet.h>
#include <MySensors.h>

void setup() {}

void presentation() {}

void loop() {}

Thank you.

Thank you for your reply.
But I do not see anything on the page indicated which corresponds to the pinning for an RFM69.
I tried to compose with this page and the RFM69 pinouts but I get the same results.
Either the ethernet part works but not the radio part.
Either the radio part works but not the ethernet part.
Is this configuration really operational?
Because a lot of post does not seem to have managed to make it work.
Cordially.

Hello,
I'm trying to make an MQTT gateway with an arduino uno, a HanRun HR911105A shield and an RFM69.
I am in version 2.3.1 of MySensors.
I realized for several years this type of gateway with NRF24 + which works without problem.
With the RFM69, if I put the MISO cable at 12, the MQTT connection tries to wait for incomprehensible IP addresses but the RFM69 starts up well.
If I remove the MISO, the MQTT connection is at the correct address and works but of course the RFM69 does not start.
I tried cabling the RST on the GND of the shield but always the same.
I looked a lot of post but I did not find anything to deal with the problem.
Any ideas ? an advice ? an experiment ?
Thanks in advance.

Hello,
I just tried version 2.3.0 with an MQTT ethernet gateway.
The gateway connects well to the broker MQTT but when the nodes send information the gateway does not return anything to the broker.
With version 2.2.0 it worked without problems.
An idea ?
Thank you.

Gateway-side traces :
320 GWT:TPC:IP=12.9.0.100
1323 MCO:BGN:STP
1324 MCO:BGN:INIT OK,TSP=1
1627 GWT:TPC:IP=12.9.0.100
2629 GWT:RMQ:MQTT RECONNECT
2838 GWT:RMQ:MQTT CONNECTED
2841 GWT:TPS:TOPIC=mhs-pub-0/0/255/0/0/18,MSG SENT
2889 GWT:TPS:TOPIC=mhs-pub-0/0/255/3/0/11,MSG SENT
2900 GWT:TPS:TOPIC=mhs-pub-0/0/255/3/0/12,MSG SENT
.......
6603 TSF:MSG:READ,24-24-255,s=255,c=3,t=7,pt=0,l=0,sg=0:
6608 TSF:MSG:BC
6610 TSF:MSG:FPAR REQ,ID=24
6612 TSF:CKU:OK,FCTRL
6615 TSF:MSG:GWL OK
7126 !TSF:MSG:SEND,0-0-24-24,s=255,c=3,t=8,pt=1,l=1,sg=0,ft=0,st=NACK:0

Thank you for the idea.
I try and I will do a report.

But is there a way to start the sketch after a delay even if the gateway does not find the broker.
I understand that this is not very interesting .... except for my library.
With a node, it is possible to start the sketch after a delay with the parameter MY_TRANSPORT_WAIT_READY_MS.

Thank you.

Hello,
I developed a library that allows you to modify and store the parameters of the #define sketches in eeprom when launching a module. Thus no need for IDE, compilation and upload.
It works well with all nodes but with an MQTT gateway it is waiting to find the MQTT broker to start the program.
But the first time, the parameters are, of course, not entered.
An idea to work around this problem?
Thank you.

It's just !
I had forgotten this subtlety that the gateway is number 0.
In MQTT what interests me is the topic of publication and subscription of the gateway.
Thank you.

Thank you for your reply.
I understand the objective but there is one point that does not seem to me to be appropriate: in my case, the indicated payload is 0 but the node number that emits is 205.
mhs4-out0/205/255/3/0/21 - payload : 0

Hello,
I have an MQTT ethernet gateway and a relay type node. Both are powered on mains.
The relay type node is registered in the controller and it is working properly.
But sometimes the relay type node sends an internal message type I_DISCOVER_RESPONSE with a payload of 0.
I do not see what this message is for and if the controller has to answer.
Can you explain to me ?
Thank you.