单项选择题 Your company has two servers that run windows server 2008 named server2 and server3, both servers have the DNS server role installed. Server3 is configured to forward all DNS requests to server2. You update a DNS record on server2, you need to ensure that server3 is able to immediately resolve the updated DNS record. What should you do?（）

单项选择题 You work as the IT professional in an international company which is named wiikigo. You are experienced in implementing and administering a network operating system. You are specialized in configuring IP addressing and services. Configuring name resolution and network access and so on.Your company is desigiing its network. The network will use an IPv6 prefix of 2001:DB8: BBCC:0000::/53. You have to identify an IPv6 addressing scheme that will support 2000 subnets. Which network mask should you use?（）

单项选择题 Your network contains an Active Directory domain named contoso.com. The domain contains two domain controllers named DC1 and DC2 that run Windows Server 2008 R2.DC1 hosts a primary zone for contoso.com. DC2 hosts a secondary zone for contosto.com.You need to ensure that DNS zone data is encrypted when the data replicates across the network. DC2 must provide authoritative responses to client computers.What should you do？（）