单项选择题 our company has computers in multiple locations that use IPv4 and IPv6. Each location is protected by a firewall that performs symmetric NAT. You need to allow peer-to-peer communication between all locations. What should you do?（）

单项选择题 Your company has a single active directory domain named contoso.com. all servers run windows server 2008. You have a public DNS server named server1, and an e-mail server named server2. Client computers outside the company domain are unable to send e-mail messages to contoso.com. you verify that the host (A) DNS record for server2 is available to external client computers. You need to ensure server2 can receive e-mail messages from external client computers. How should you configure the contoso.com DNS zone?（）

单项选择题 Your network contains an Active Directory forest. The functional level of the forest is Windows Server 2008 R2.You plan to deploy DirectAccess.You need to configure the DNS servers on your network to support DirectAccess.What should you do？（）