Question : dns server is not reachable in exchange server 2010

setup cannot contact the primay dns server(192.168.1.254) using tcp prt 53.check that the ip address of the dns server is correct and that the dns server is reachable. I am directly connected to my internet and 192.168.1.254 is Ip address of dns server in the router.

Answer : dns server is not reachable in exchange server 2010

You want to point it to an Active Directory-enabled DNS server, I don't suppose that the DNS server in your router is able to resolve queries for AD (unless you have forwarding configured).