Wifi STA+SoftAP have DHCP Server listening and answering to STA interface

[cpainchaud]

Hardware:

Board: ESP32 Dev Module
Arduino IDE Version : 10805
ESP SDK version: v3.2.3-14-gd3e562907
IDE name: Platform.io
Flash Frequency: 40Mhz
PSRAM enabled: no
Upload Speed: 940000
Computer OS: Windows 10

Description:

When STA mode is on along with SoftAP, DHCP server will respond on STA interface as well which creates network issues.
If I add this code: tcpip_adapter_dhcps_stop(TCPIP_ADAPTER_IF_AP) then ofc it stops happening but AP interface is not serving DHCP anymore.
Then if I use tcpip_adapter_dhcps_stop(TCPIP_ADAPTER_IF_STA) it just has no effect.

Logs are showing plenty of:
dhcps: send_offer>>udp_sendto result 0

Sketch: (leave the backquotes for code formatting)

//Change the code below by your sketch
#include <Arduino.h>

void setup() {
}

void loop() {
}

Debug Messages:

Enable Core debug level: Debug on tools menu of Arduino IDE, then put the serial output here 

[me-no-dev]

ESP SDK version: v3.2.3-14-gd3e562907 seems a bit old. We are tracking v3.3 currently. I am not aware of that issue there

[cpainchaud]

@me-no-dev same story with the following version:
Arduino IDE Version : 10805
ESP SDK version: v3.3.4-432-g7a85334d8

dhcps: send_nak>>udp_sendto result 0

[me-no-dev]

can you please provide minimal example to debug this?

[cpainchaud]

I supppose it should do it:

setup{
WiFi.enableAP(true);
if( !WiFi.softAP("MyAp", "") )
          Serial.println("WIFI AP start FAILED");

WiFi.config(IPAddress((uint32_t) 0), IPAddress((uint32_t) 0), IPAddress((uint32_t) 0));
WiFi.begin("HomeNetwork", "password");
WiFi.setAutoConnect(true);
WiFi.setAutoReconnect(true);
}

output when connecting a device to my home network:

rst:0x1 (POWERON_RESET),boot:0x1e (SPI_FAST_FLASH_BOOT)
configsip: 0, SPIWP:0xee
clk_drv:0x00,q_drv:0x00,d_drv:0x00,cs0_drv:0x00,hd_drv:0x00,wp_drv:0x00
mode:DIO, clock div:1
load:0x3fff0018,len:4
load:0x3fff001c,len:1216
ho 0 tail 12 room 4
load:0x40078000,len:9720
ho 0 tail 12 room 4
load:0x40080400,len:6352
entry 0x400806b8
hello
dhcps: send_offer>>udp_sendto result 0
dhcps: send_offer>>udp_sendto result 0
dhcps: send_nak>>udp_sendto result 0

[me-no-dev]

I see the messages but the packets are not going to the STA interface at all

[cpainchaud]

Interesting! I was assuming this device was the issue because of these messages and didn't fire a tcpdump.

I think it's worth fixing/ignoring the requests anyways to be 100%clean, your call...

And now I need to find out who's sending these bogus DHCP ...

thank you

[stale]

[STALE_SET] This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[stale]

[STALE_DEL] This stale issue has been automatically closed. Thank you for your contributions.

[PhilLu58]

About: "dhcps: send_nak>>udp_sendto result 0" in serial
Hello,
Probably old issue, but I cannot fix it :-(
Is there a bug fix or reason for that issue?
Many thanks,
Phil.