QNX 4.25 Voyager can't resolve domain name

I have both TCPIP 4.25 and 5.1 installed, command lines utilities like traceroute/ping/wget works but Voyager always throws “DNS failure”, some websites can view by using IP address.
How can I solve this issue?

I’d start by testing DNS outside of voyager. For example:

ping yahoo.com

If this works, then the problem is Voyager. If not, you don’t have DNS set up correctly. The usual way is with the file /etc/resolv.conf.

yeah ping yahoo.com works.

If tcp/ip is working, but Voyager is giving you DNS errors, the only thing I can think might cause this is if you have Voyager setup to use a proxy server, but it is set up incorrectly.

But I didn’t use any proxy server in Voyager, the box in connection tab is not checked.

Then I have no idea.