MQX Software SolutionsのトピックRetrieving a second DNS server IP

Retrieving a second DNS server IP

panpwr — Sun, 11 Nov 2012 14:35:22 GMT

Hello,

When I connect my laptop to the my office network, I receive 2 DNS addresses.

However, When I use my TWR-K60D100M, with the following code , I receive only one DNS address (I assume it should be stored automatically in the DNS list, once I get an IP using the DHCP client??):

/* Get IP address from DHCP server */

result = ipcfg_bind_dhcp_wait(BSP_DEFAULT_ENET_DEVICE, FALSE, NULL); //FALSE = don't bind static IP after failure

if (result == IPCFG_OK)

{

is_successful = ipcfg_get_ip(BSP_DEFAULT_ENET_DEVICE, &ip_data);

if (is_successful)

{

// Get DNS_1 server

dns = ipcfg_get_dns_ip (BSP_DEFAULT_ENET_DEVICE, 0);

if (dns != 0)

{

// THE FIRST DNS IS VALID!!!

}

// Get DNS_2 server

dns = ipcfg_get_dns_ip (BSP_DEFAULT_ENET_DEVICE, 1); //<<=== This returns zero dns address, rather than the 2nd DNS which should have been supplied by DHCP server.

}

Re: Retrieving a second DNS server IP

panpwr — Mon, 19 Nov 2012 13:11:57 GMT

Can someone please pick this question up?

Thank you,

Lior.

Re: Retrieving a second DNS server IP

c0170 — Tue, 20 Nov 2012 06:21:28 GMT

Hello Lior,

I am going to ask around :smileywink:

Regards,

MartinK

Re: Retrieving a second DNS server IP

panpwr — Tue, 20 Nov 2012 09:08:02 GMT

Thanks!

Re: Retrieving a second DNS server IP

karelm_ — Tue, 27 Nov 2012 13:33:48 GMT

Hi, after quick look at code of ipcfg_get_dns_ip function it seems, that if you use lightweight DNS resolver (which is default in MQX) only one DNS server IP is stored (in variable LWDNS_server_ipaddr) and this address is returned (zero is return value for any other DNS server index other than zero). If you want to have multiple DNS servers, than you have to use full DNS resolver by adding following configuration to file user_config.h:

#define RTCSCFG_ENABLE_LWDNS 0

#define RTCSCFG_ENABLE_DNS 1

#define RTCSCFG_ENABLE_LOOPBACK 1

Best Regards,

Karel

Re: Retrieving a second DNS server IP

panpwr — Tue, 27 Nov 2012 13:37:28 GMT

I will try that, that you very much!

Re: Retrieving a second DNS server IP

michris — Wed, 27 Feb 2013 08:35:03 GMT

Dear,

I tried to add a second and third DNS server address, but it seems not to work.

As understood in this thread, I can not use LWDNS, so I used DNS instead of LWDNS

(I use MQX3.8.1 on a K70 device)

// User_config.h :

// #define RTCSCFG_ENABLE_LWDNS 0

// #define RTCSCFG_ENABLE_DNS 1

// #define RTCSCFG_ENABLE_LOOPBACK 1

_ip_address DNS_server_ipaddr;

DNS_server_ipaddr = inet_addr("8.8.8.8");

// Open dns server1

if (ipcfg_add_dns_ip(ENET_DEVICE,DNS_server_ipaddr) == TRUE) {printf("DNS added ok");}

DNS_server_ipaddr = inet_addr("208.67.222.222");

// Open dns server1

if (ipcfg_add_dns_ip(ENET_DEVICE,DNS_server_ipaddr) == TRUE) {printf("DNS added ok");}

DNS_server_ipaddr = inet_addr("208.67.220.220");

// Open dns server2

if (ipcfg_add_dns_ip(ENET_DEVICE,DNS_server_ipaddr) == TRUE) {printf("DNS added ok");}

printf("DNS0

: %d.%d.%d.%d",IPBYTES(ipcfg_get_dns_ip(ENET_DEVICE,0)));

printf("DNS1

: %d.%d.%d.%d",IPBYTES(ipcfg_get_dns_ip(ENET_DEVICE,1)));

printf("DNS2

: %d.%d.%d.%d",IPBYTES(ipcfg_get_dns_ip(ENET_DEVICE,2)));

The result is that it seems to add the three dns servers => 3x DNS added ok

But when I print them out, I only have the last DNS IP at the first location. (so it seems the overwrite each other ???)

DNS0 : 208.67.220.200

DNS1 : 0.0.0.0

DNS2 : 0.0.0.0

Any idea's?

Thanks in advance.

Regards,

Michris

Re: Retrieving a second DNS server IP

danielchai — Tue, 28 Jan 2014 15:13:51 GMT

Hi Michris,

I am facing the same problem. After change the

#define RTCSCFG_ENABLE_LWDNS 0

#define RTCSCFG_ENABLE_DNS 1

#define RTCSCFG_ENABLE_LOOPBACK 1

I still only get one DNS server IP.

Did you solve it?

Thank you.

-Daniel

Re: Retrieving a second DNS server IP

michris — Tue, 28 Jan 2014 16:41:27 GMT

Hi Daniel,

I still have the same problem, even with the latest version of MQX.

Regards,

Michris

Re: Retrieving a second DNS server IP

hfyuksel — Mon, 27 Apr 2020 10:59:31 GMT

I have 2 DNS servers. But one return to me. No solution proposal proposed before has solved this problem.
https://community.nxp.com/message/317385?commentID=317385#comment-317385
and
https://community.nxp.com/thread/301815
The version i use is 4.2.0.2

#define RTCSCFG_ENABLE_LWDNS 0
#define RTCSCFG_ENABLE_DNS 1
#define RTCSCFG_ENABLE_LOOPBACK 1
The above suggestions did not solve the problem.

Can you help me?