AT v0.50 DNS FAIL

[ESP_Faye]

Hi,

We bought a "TL-MR3020", but we still can not duplicate this problem.

The "DNS Fail" only happened when the router does not able to access WAN.

Could you please provide the WiFi settings of your router ?

[sukarsa]

Hi Faye,

Sorry for the delay,
As I mentionned earler, the TL-MR3020 was on Wifi-mode : WISP Client Router
It is connected to a wifi provider (another wifi router), for example in a hotel.

A computer connected to MR3020 can connect to the internet.

Please be reminded that I tried different DNS setting on the TL-MR3020 and there is no improvement.
Is ESP8266 connect to the DNS given by the router or is it using it's own DNS?

Please find attached the setting of TL-MR3020.

Regards.

[ESP_Faye]

Hi,

We tested "TL-MR3020" as your settings, but sorry that we still can not duplicate your problem.

Could you try it with another "TL-MR3020" or provide the captured WiFi packets for debugging ?

[sukarsa]

Hi Faye,
.
I may not have the proper tools to monitor wifi packets. I will try to test this later.
.
There is one question that you have not answer: Is ESP8266 using the DNS setting given by the router?
Because I tried to change the values and it has no effect. If ESP8266 is using a fixed-ip DNS, then the MR3020 problem may be related to the place (where I tested it).
That explains that you can not reproduce the problem over there.
.
In any case, if we want to have ESP8266 as a serious industrial product, then either it MUST use the DNS given by router, or you MUST develop DNS setting command.
In a closed IP network it is NOT possible to use a fixed-IP DNS, and there is already one possible client where I might have to deploy it in their premise.

Please consider.

[ESP_Faye]

Hi,

ESP8266 is using fixed-IP DNS, but there is an API espconn_dns_setserver, users can call it to set DNS server.

Could this "espconn_dns_setserver" help ?

[sukarsa]

Hi Faye,

Sorry for the late reply, just got back from field testing.

I think the connection problem that I observed also in the field is due to DNS problem, because it was passing through private network. When I tried through 3G network (another router) it was working fine.
.
I would appreciate it if you can give me the command line to change the dns server.
Is there access to this "espconn_dns_setserver" API from the serial port / AT command?
FYI : We are planning to use WROOM-02 for production. (Does it have newer AT command?)
.
Thanks for your help.

[damijans]

A year after, I had the same problem. I was fighting with it for a day and finally I found the issue was in typo mistake. After entering "goog " (with space character at the end) I have deleted the last space with delete key and continue writing the URL. In minicom terminal I saw correct "google" token, but in fact minicom forward to the ESP the following sequence "103 111 111 103 30 8 108 101" instead of "103 111 111 103 108 101", what reflects in "DNS fail" error code.

But probably, this is not the same issue as you had