Your network consists of a single Active Directory domain. You have a domain controller named Server1 that runs Windows Server 2003 Service Pack 2 （SP2）. 
The DNS service is installed on Server1. Server1 contains only Active Directory-integrated zones. Zone transfers are disabled for all zones. You need to back up the DNS zones on Server1. 
What should you do？（）

Your network consists of a single Active Directory domain. All servers run Windows Server 2003 Service Pack 2 （SP2）.A firewall separates the internal network from the Internet. 
The firewall blocks all outbound traffic except for HTTP and SMTP traffic.You install a DNS server. The DNS server is configured to use the default root hints. You need to ensure that the DNS server can resolve the host names on the Internet. 
Which port should you open on the firewall？（）