dns not working on embedded device?

DNS is not working on my embedded device, I can do ping to 74.125.77.147, but ping to google 开发者_运维问答's ip address 209.85.231.104 works but ping google.com is not working.

embedded device runs embedded linux, It is able to get its ip from dhcp, board is connected to network via Ethernet connection.

What can be the reason?

Look at the file /etc/resolv.conf. The DHCP client should have put the nameserver's IP in there. If not, then your DHCP server may not be passing a DNS address or the client may be ignoring it?

If there's nothing in your /etc/resolv.conf then try adding the line:

nameserver dns-ip-address

Confirm that DNS resolution works by pinging google.com. Then get your DHCP server to send a DNS IP as part of it's configuration to the client.