A new server was installed. Most clients are located in the same subnet as the server and can successfully access the server. Clients located on different subnets have been unable to access the server， but have no trouble accessing other servers on their subnet. 
Which of the following is the reason that these clients are unable to access the server？（）

单项选择题A server is connected to a gigabit Ethernet switch and has negotiated 1Gbps   Full Duplex. When transferring large files to and from other servers on the segment via FTP slow performance is noticed.All network cabling，network hardware and server hardware were verified to be working correctly.  Which of the following could be done to improve performance？（）

A. Decrease the TCP window size.
B. Increase the UDP window size.
C. Increase the TCP window size.
D. Decrease the UDP window size.

单项选择题A new server was installed for the purpose of monitoring network traffic. The network has been configured in such a way that all traffic will be mirrored out the port this server is connected to. When reviewing the network traffic logs on the server only traffic destined to the server is listed in the logs. Which of the following is preventing the server from seeing all network traffic？ （）

A. NIC filtering is enabled.
B. Port security is configured.
C. NIC is not in promiscuous mode.
D. NIC is in promiscuous mode.

单项选择题Users have reported that they cannot access certain Internet sites. An administrator wants to test that the sites are properly resolving to an IP address.  Which of the following tools would allow the administrator to test name resolution？（）

A. net view
B. ipconfig
C. dig
D. ifconfig

单项选择题WhichofthefollowingprotocolswouldMOSTlikelybeusedintheestablishmentofanIPSecVPN tunnel？（）

A. AES 
B. TKIP
C. 802.1q
D. ISAKMP

单项选择题WhichofthefollowingRAIDlevelscanwithstandthesimultaneouslossoftwophysicaldrivesinan array？（）

A. RAID 0
B. RAID 3
C. RAID 5
D. RAID 10