AT v0.50 DNS FAIL

[sukarsa]

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: Select all

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.

[ESP_Faye]

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 !

[sukarsa]

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

[sukarsa]

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,

[ESP_Faye]

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 !

[sukarsa]

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.

[ESP_Faye]

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) ?

[sukarsa]

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.

[ESP_Faye]

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 ?

TL-MR3020.jpg (6.25 KiB) Viewed 22174 times

[sukarsa]

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.
.