DNS issues then IP Error when using CIPSTART with an IP address

[clarksn]

Hi,

I'm using AT+CIPSTART to establish a TCP link and my error trapping picked up quite a few fails and on expanding my debugging I discovered I seemed to be getting quite a few DNS fails for no apparent reason (can typically take 10-15 seconds or so for this error to be reported).

As a workaround I tried the IP address instead of the domain name but this immediately returns with an IP ERROR message. Although I was already on fairly current firmware I upgraded to AT Bin V1.6.1 but the symptoms are identical as the slightly earlier firmware.

The problem is reproducible on several different Arduinos including those with an ESP-01 and those with a Wemos Arduino Mega with integral 8266 flashed with the above firmware.#

Any ideas on both the DNS issue and the fact that substituting the server name with a pre-resolved IP fails immediately with an IP ERROR message?

thanks

[Her Mary]

Which IP address you used? An AT log list will be very helpful for debugging.

[kreakemp]

I am also facing same issue. Please help me regarding this. The server is running fine but can't able to connect.


Here is the command sequence that i have followed: (


(Time in milli Sec) (Command)
14487--> AT

14488-->

14489--> OK

29891--> AT+CWQAP

29892-->

29892--> OK

38195--> AT+CIPMODE?

38196--> +CIPMODE:0

38196-->

38197--> OK

170120--> AT+CWJAP="KreakEmp","kkpkkp123"

173322--> WIFI CONNECTED

174123--> WIFI GOT IP

175223-->

175224--> OK

183226--> AT+CIPMUX=0

183227-->

183228--> OK

188529--> AT+CIPMUX=1

188530-->

188530--> OK

213635--> WIFI DISCONNECT

219237--> WIFI CONNECTED

220238--> WIFI GOT IP

227940--> AT+CIFSR

227942--> +CIFSR:STAIP,"192.168.43.116"

227944--> +CIFSR:STAMAC,"ec:fa:bc:27:67:58"

227989-->

228003--> OK

256025--> AT+CIPSTART=1,"TCP","52.66.148.290",61234

259227-->

259227--> ERROR

259228--> 1,CLOSED

260630--> WIFI DISCONNECT

264032--> WIFI CONNECTED

266733--> WIFI GOT IP

[Her Mary]

Maybe you can try to ping the "52.66.148.290" firstly, to see if it can ping successfully.