ESP8266 Developer Zone

Re: AT v0.50 DNS FAIL

2016-11-16T02:41:59+08:00

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

Statistics: Posted by damijans — Wed Nov 16, 2016 2:41 am

Re: AT v0.50 DNS FAIL

2016-02-18T05:47:09+08:00

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.

Statistics: Posted by sukarsa — Thu Feb 18, 2016 5:47 am

Re: AT v0.50 DNS FAIL

2015-12-21T10:24:57+08:00

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 ?

Statistics: Posted by ESP_Faye — Mon Dec 21, 2015 10:24 am

Re: AT v0.50 DNS FAIL

2015-12-18T19:06:22+08:00

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.

Statistics: Posted by sukarsa — Fri Dec 18, 2015 7:06 pm

Re: AT v0.50 DNS FAIL

2015-12-16T17:01:35+08:00

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 ?

Statistics: Posted by ESP_Faye — Wed Dec 16, 2015 5:01 pm

Re: AT v0.50 DNS FAIL

2015-12-10T01:11:53+08:00

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.

Statistics: Posted by sukarsa — Thu Dec 10, 2015 1:11 am

Re: AT v0.50 DNS FAIL

2015-11-30T16:55:52+08:00

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 ?

Statistics: Posted by ESP_Faye — Mon Nov 30, 2015 4:55 pm

Re: AT v0.50 DNS FAIL

2015-11-25T17:27:35+08:00

Yes. That is the MR3020 router that I used.
During the test I use it as wifi router / WISP mode (without 3G key) to simplify the test.
.

Statistics: Posted by sukarsa — Wed Nov 25, 2015 5:27 pm

Re: AT v0.50 DNS FAIL

2015-11-25T09:58:12+08:00

Hi,

Sorry that we do not have this router now, but we are going to buy one.

I did some searching about "TPLINK 3020", please help us to confirm that is it the router "TL-MR3020" ? Does it look like the picture below ?

Statistics: Posted by ESP_Faye — Wed Nov 25, 2015 9:58 am

Re: AT v0.50 DNS FAIL

2015-11-24T23:51:54+08:00

Hi,
I tested with other domains name and my own domain (registerd .com) and it's the same: DNS fail.
Using other router it's ok.

Regards.

Statistics: Posted by sukarsa — Tue Nov 24, 2015 11:51 pm

Re: AT v0.50 DNS FAIL

2015-11-24T17:50:11+08:00

Hi,

"www.google.com" is blocked by China, so we can not test to access to it.

With router "TPLINK-3020", can ESP8266 connect to other servers(except google) ?

Statistics: Posted by ESP_Faye — Tue Nov 24, 2015 5:50 pm

Re: AT v0.50 DNS FAIL

2015-11-24T17:01:08+08:00

Thanks for the suggestion.
I may try adding AT command for DNS later. For now I need to get the system going, so I just replace the router.
I think this problem is IMPORTANT to investigate by Espressif, because there is a RISK that esp8266 will not be compatible with the router that exist in the user's place.
.
Esp8266 is a very nice product, so I hope that this bug can be solved soon.
We can not sell this product with esp8266 inside knowing that it MAY NOT work with SOME routers in the market.
.
Regards.

Statistics: Posted by sukarsa — Tue Nov 24, 2015 5:01 pm

Re: AT v0.50 DNS FAIL

2015-11-23T15:30:09+08:00

Hi,

Sorry that we do not have AT command to set DNS server.

But you can add your own AT command to set it by calling espconn_dns_setserver.

How to add user-define AT commands ?

Thanks for your interest in ESP8266 !

Statistics: Posted by ESP_Faye — Mon Nov 23, 2015 3:30 pm

Re: AT v0.50 DNS FAIL

2015-11-20T17:36:40+08:00

Hi,
Is there any solution to this problem?
I think it's a bug in the DNS client in esp8266.
Can you please add at-command to control the DNS?
It can be one command to set an IP for the DNS and a timeout value.
This DNS setting IS NECESSARY for fixed IP application.
.
Please consider,

Statistics: Posted by sukarsa — Fri Nov 20, 2015 5:36 pm

Re: AT v0.50 DNS FAIL

2015-11-18T17:35:31+08:00

Hi,
.
Yes. A PC is connected to the same router, and it can reach google.com.
Can you please give me a link/info about omnipeek so I can get the trace.
.
I have also done quite a few investigations to understand the problem better:
1. All DNS setting on the router that I have tried are not working:
- 192.168.0.254 (the router as DNS proxy)
- 8.8.8.8 and 8.8.4.4 and 222.... (opendns).
.
2. I have left the system retrying again and again, and after a long time, for once it got connected, but the next ipstart failed again.
So perhaps this is related to timeout of the DNS client in ESP8266 firmware!!
.
3. I tried with fix ip using IPSTA_CUR "192.168.0.100","192.168.0.254","255.255.255.0" and it WORKS FOR FIRST TIME ONLY!
So the first IPSTART session works ok, but after IPCLOSE it doesn't work anymore: the next IPSTART gives DNS Fail.
.
4. I have tested with another TPLINK M5350 and it works fine.
.
Suggestion: Please add AT command for DNS settings (if using fix-ip this is necessary!!), and also timeout.
.
Ami

Statistics: Posted by sukarsa — Wed Nov 18, 2015 5:35 pm

Re: AT v0.50 DNS FAIL

2015-11-18T10:03:44+08:00

Hi,

Connect your PC to router "TPLINK-3020", can it access to "www.google.com" ?

Can you provide the captured WiFi packets by omnipeek for debugging ?

Thanks for your interest in ESP8266 !

Statistics: Posted by ESP_Faye — Wed Nov 18, 2015 10:03 am

AT v0.50 DNS FAIL

2015-11-17T22:52:02+08:00

Hi,
.
I have a strange "DNS-Fail" problem using ESP8266 connected to a router TPLINK-3020. (I tried with other router it's working)
I have upgraded to the latest AT version 0.50.
The following is the AT-trace:

Code:

ready

AT+GMR
AT version:0.50.0.0(Sep 18 2015 20:55:38)
SDK version:1.4.0
compile time:Sep 18 2015 21:32:07
OK
                                                                            
WMODE=3
OK
IPMUX=1
OK
WDHCP_CUR=2,1
OK
+CWJAP_CUR="TL-MR3020","*****"
WIFI CONNECTED
WIFI GOT IP
OK
+CWJAP_CUR?
+CWJAP_CUR:"TL-MR3020","f8:1a:67:52:ee:a5",11,-54
OK
+CIPSTART=4,"TCP","www.google.com",80
DNS Fail
ERROR
+CIPSTART=4,"TCP","www.google.com",80
DNS Fail
ERROR

.
Which DNS does the esp8266 module use?
On the router DHCP setting I tested with different DNS setting (8.8.8.8, 222...) but all give the same result.
Can someone help me to solve this problem?

Thank you.

Statistics: Posted by sukarsa — Tue Nov 17, 2015 10:52 pm