DNS error and +kcnxcfg

Hi,

HL7802, v.4.6.8

I am trying to establish a simple TCP connection with google.com but fail to do so:

AT+KTCPCFG=1,0,“2a00:1450:400f:801::200e”,80, , , ,1 // IPV6 google address connects ok
+KTCPCFG: 1
OK
at+ktcpcnx=1
OK
+KCNX_IND: 1,1,1
+KTCP_IND: 1,1
AT+KTCPCFG=1,0,“www.google.com”,80, , , ,1
+KTCPCFG: 2
OK
at+ktcpcnx=2
OK
+KTCP_NOTIF: 2,3 // DNS error

So i then try to add google’s IPV6 DNS servers but i get an error.

at+kcnxcfg=1,“GPRS”,“iot”,"","",“IPV6”,"","","","::",“2001:4860:4860::8888”,“2001:4860:4860::8844”
ERROR

Is there a different command that handles DNS or is it strictly up to the provider (they claim they support DNS resolution)?

thanks

Hi @hkiol,

I have just tried your case on my HL7802 module, it is successfully when establishing TCP connection through IP address and DNS. You can refer below log:

15:12:46.688 on 06-May-2021> ati
15:12:47.180 on 06-May-2021> 
15:12:47.180 on 06-May-2021> HL7802
15:12:47.180 on 06-May-2021> 
15:12:47.180 on 06-May-2021> OK
15:12:47.180 on 06-May-2021> ati3
15:12:47.667 on 06-May-2021> 
15:12:47.667 on 06-May-2021> HL7802.4.6.8.0
15:12:47.667 on 06-May-2021> 
15:12:47.667 on 06-May-2021> OK
15:12:47.667 on 06-May-2021> at+cereg?
15:12:48.132 on 06-May-2021> 
15:12:48.132 on 06-May-2021> +CEREG: 0,1
15:12:48.132 on 06-May-2021> 
15:12:48.132 on 06-May-2021> OK
15:12:48.132 on 06-May-2021> at+cops?
15:12:48.620 on 06-May-2021> 
15:12:48.620 on 06-May-2021> +COPS: 0,0,"",9
15:12:48.620 on 06-May-2021> 
15:12:48.620 on 06-May-2021> OK
15:12:48.620 on 06-May-2021> at+kcnxcfg=1,"GPRS","my APN",,,"IPV6"
15:12:49.996 on 06-May-2021> 
15:12:49.996 on 06-May-2021> OK
15:12:49.996 on 06-May-2021> AT+KTCPCFG=1,0,"2a00:1450:400f:801::200e",80,,,,1
15:12:52.425 on 06-May-2021> 
15:12:52.425 on 06-May-2021> +KTCPCFG: 1
15:12:52.425 on 06-May-2021> 
15:12:52.425 on 06-May-2021> OK
15:12:52.425 on 06-May-2021> at+ktcpcnx=1
15:12:55.772 on 06-May-2021> 
15:12:55.786 on 06-May-2021> OK
15:12:55.787 on 06-May-2021> 
15:12:55.804 on 06-May-2021> +KCNX_IND: 1,1,1
15:12:55.804 on 06-May-2021> 
15:12:57.593 on 06-May-2021> +KTCP_IND: 1,1
15:12:57.593 on 06-May-2021> AT+KTCPCFG=1,0,"www.google.com",80,,,,1
15:13:04.945 on 06-May-2021> 
15:13:04.960 on 06-May-2021> +KTCPCFG: 2
15:13:04.960 on 06-May-2021> 
15:13:04.960 on 06-May-2021> OK
15:13:04.960 on 06-May-2021> at+ktcpcnx=2
15:13:14.777 on 06-May-2021> 
15:13:14.808 on 06-May-2021> OK
15:13:14.808 on 06-May-2021> 
15:13:15.430 on 06-May-2021> +KTCP_IND: 2,1

So can you try again with above AT commands?

You said that:

Please help me explain the purpose of your above +KCNXCFG command.

Thanks,

Hi,

I am trying to change the DNS servers (is it possible?) beacuse it seems that there is no DNS resolution present at this time.
Also:

at+kcnxcfg?
+KCNXCFG: 1,“GPRS”,“iot”,"","",“IPV6”,“0.0.0.0”,“0.0.0.0”,“0.0.0.0”,"::","::","::",2
OK
AT+CGCONTRDP
+CGCONTRDP: 1,5,“iot.mnc001.mcc202.gprs”,254.128.0.0.0.0.0.0.33.14.210.211.183.218.174.139.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255,
OK

What is the DNS server of my device?

thanks

Hi @hkiol,

I think that we cannot change the DNS servers, it will be provided by the network during the PDP connection.

In your comment:

It looks like DNS was not provisioned.
Because I cannot connect to your network so I try on my network and it works fine. You can refer this log:

at+cgcontrdp

+CGCONTRDP: 1,5,"xxx.gprs",11.184.108.234.255.255.255.252,11.184.108.233,203.113.131.6,203.113.131.5,,,,,,,,,
+CGCONTRDP: 1,5,"xxx.gprs",254.128.0.0.0.0.0.0.213.47.73.72.141.133.228.2.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255.255,,36.2.8.0.32.255.119.119.0.0.0.0.0.0.0.1,36.2.8.0.32.255.153.153.0.0.0.0.0.0.0.1,,,,,,,,

OK

I recommend that you should contact network provider or distributor for more support.

Please feel free to share any concerns you have. Help us tick Solution if your question is answered.

Thanks,