DNS client problem

[spiras]

Hello, using 4.7.1 we have a case where DNS resolution fails;
the DNS server is pingable from the device;
in tcpdump we see the correct query packet and the response from the server,
but the device does not receive the response.
Any idea?

I enabled the FNET_DEBUG_DNS macro, this is the output:
resolving apps.xyz.com
Sending query...
Sending query...
Sending query...
Sending query...
Sending query...
Sending query...
Timeout
not resolved

On the same device, telnet service is working normally.

Here is the output from tcpdump:

10:25:15.473350 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580+ A? apps.xyz.com. (50)
10:25:15.473761 IP 10.150.54.5.53 > 10.176.130.170.50068: 21580* 2/3/6 CNAME n0611355.xyz.com., A 10.151.38.166 (253)
10:25:16.475843 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580* 2/3/6[|domain]
10:25:17.485619 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580* 2/3/6[|domain]
10:25:18.495626 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580* 2/3/6[|domain]
10:25:19.505684 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580* 2/3/6[|domain]
10:25:20.515635 IP 10.176.130.170.50068 > 10.150.54.5.53: 21580* 2/3/6[|domain]
10:25:21.573103 IP 10.176.130.170.50069 > 10.150.54.5.53: 20838+ A? apps.xyz.com. (50)
10:25:21.573280 IP 10.150.54.5.53 > 10.176.130.170.50069: 20838* 2/3/6 CNAME n0611355.xyz.com., A 10.151.38.166 (253)

Thanks a lot!

[Andrej Butok]

It can be related to: https://github.com/butok/FNET/issues/7

[spiras]

thanks; I'm afraid it's not related, because:
I tracked down to _fnet_dns_poll
it goes into FNET_DNS_STATE_RX
received is always 0

I'm still investigating

[spiras]

yes it was related to that same issue;
the value of received was not actually 0;
it receives a CNAME as rejects it

thanks for the hint