• Resolved

CC3220: DNS server not published by internal DHCP server in AP mode

Part Number: CC3220

Hi,

I tried to configure the AP mode in Uniflash so that the only enabled network applications are HTTP and DHCP (mDNS and DNS are OFF).

Also, I have entered IP addresses in the network settings (including a DNS server).

I found out that the DNS server does not get sent/communicated to the clients that connect to the DHCP server.

If the DNS application is running, the DNS server address is sent correctly.

Please note that in this example the DNS IP is equal to the gateway IP, but the same happens if you use another DNS IP.

How can you force the DHCP server to send the DNS IP when a client connects... ?

BR,

Salvatore

  • In reply to Salvatore Castellano:

    OK, I will try it tonight. Why do I need to turn off the DNS server? That is on port 53 which should not interfere with DHCP. Or am I misunderstanding?

    I am also using wireshark but only see DHCP requests from the client.  No response from CC3220.  The existing code already configures it for AP, DHCP, DNS, mDNS, and DHCP.  All I did was disable DHCP.  I don't see why it wouldn't work unless there is some dependency I don't understand.

  • In reply to Salvatore Castellano:

    I got it working. There was a task dependency where sl_start had not been called before the recvfrom() call. DHCP appears to work good, although I haven't tested it too much.

    I have run into a new issue. If I enable the DHCP task, the onboard HTTP server does not work and the CPU locks up when a device requests the webpage. Stack size is good all all tasks (DHCP task only uses ~2K). Are you having issues using the onboard web server? I find this very strange. If I disable DHCP task and use CC3220 DHCP, everything works fine and web page comes up just fine.
  • In reply to Salvatore Castellano:

    I got it all working now with my code. I will test more and report back on the reliability. Thank you again for sharing! I did notice that your DHCP messages don't show up in wireshark when I filter "bootp".
  • In reply to Andrew5821:

    Hi,

    glad you got it working. :-)

    1. The DNS server does not have to be disabled; you are correct; in my case it had to, because I use my own DNS server, in order to have my captive portal working.

    2. I am not sure why you are not seeing the DHCP server responses in Wireshark; are you using the multicast address 255.255.255.255 in the UDP sendto() method ? In my setup here, I see all responses using the bootp filter in Wireshark.

    3. If you have any feedback, please do let me know! :-)

    BR,

    Salvatore