I cannot communicate with primary dns server 172.29.71.1 is there a way i can reset it automaticaly or manually

You need to be more specific!

1. are you trying to simply access a dns server from home to use internet?
2. are you trying to access a dns server that has been configured to be used internally in a corporation for the porposes of resolving ip address into name servers inside your intranetwork??
3. what operating system do you have, xp, 2000, server 2003, vista?
4. what is it in general what you're trying to accomplish (ex. be able to go on internet from your home, from your corporate computer...etc).
5. are you trying to reset a dns server for the porposes of connecting to it? is that a server you're in charge with (is that server part of the network you manage)?? if that's the case. you can restart the DNS server service located in your DNS server 172.29.71.1. make sure also your dns client on the local machine is enable or you won't get get it to work. you can also try restarting the service altogether.
6. also check that your subnetting homework is correct and that you have ip addresses and your subnet mask properly entered on you DNS server and your ip address matches both your DNS server and client using that server to resolve ip address.

if you are just trying to use your home computer to go online using the dns server your ip address has for you to use for the porpose of going online and browse your favorite websites.. more than likely you don't need to enter any dns server configuration as that is dinamically assigned, you will only have to configure your tcp/ip properties for your ip address and dns server configuration to be assigned or configured automatically.

You cam try doing a power cycle. Turn off the modem, router (if you have one) and your computer. after 1 minute turn on modem first then router and computer. If you still can't communicate or ping the DNS it could be a firewall that is blocking it.