MCTS 70-642 Case Studies & Practical Application 2

Question 1

A company's branch office connects to headquarters via a site-to-site VPN. Users report intermittent connectivity failures every few hours. The VPN tunnel re-establishes automatically after a few minutes. What is the most likely cause?

Accepted Answer

IKE Phase 1 lifetime mismatch between endpoints

Answer

IKE SA lifetime mismatches cause tunnels to drop and renegotiate at unpredictable intervals when one side expires before the other.

Question 2

An administrator needs to ensure that DHCP leases from a rogue DHCP server cannot reach clients on a specific VLAN. Which switch feature should be enabled?

Accepted Answer

DHCP snooping on the VLAN

Answer

DHCP snooping drops DHCP offers from untrusted ports, preventing rogue DHCP servers from assigning addresses to clients.

Question 3

A Windows Server 2008 R2 DNS server is authoritative for contoso.com. External clients cannot resolve names in contoso.com, but internal clients can. The firewall allows UDP/TCP port 53. What should the administrator check next?

Accepted Answer

Whether the zone allows zone transfers to the external DNS server

Answer

If zone transfers are not permitted to the external/secondary DNS server, external clients querying that server receive NXDOMAIN responses.

Question 4

After enabling IPv6 on a Windows Server 2008 R2 network, administrators notice that link-local addresses are assigned but global unicast addresses are not. DHCPv6 is not in use. What is missing?

Accepted Answer

Router Advertisement messages with a valid prefix

Answer

SLAAC requires Router Advertisement messages containing a valid /64 prefix so hosts can generate their global unicast addresses.

Question 5

A company uses Network Policy Server (NPS) for RADIUS authentication of VPN clients. A new user group must be denied VPN access on weekends. How should the administrator accomplish this?

Accepted Answer

Create a new network policy with a day-and-time restriction and set access to Deny

Answer

NPS network policies support day-and-time conditions; setting the policy to Deny during weekend hours blocks VPN access for the targeted group.

MCTS 70-642 Exam Practice Test

MCTS 70-642 Exam Practice Test

MCTS 70-642 Case Studies & Practical Application 2