MCTS 70-642 Case Studies & Practical Application 4 — Questions and Answers
Question 1: A Windows Server 2008 R2 server running the Routing and Remote Access role is configured for demand-dial routing. The demand-dial interface connects successfully but drops after exactly 5 minutes of idle time. How should the administrator fix this?
- Increase the idle disconnect time on the demand-dial interface (Correct answer)
- Change the dial-out credentials on the demand-dial interface
- Enable persistent mode on the demand-dial interface
- Add a static route with a lower metric than the demand-dial route
Correct answer: Increase the idle disconnect time on the demand-dial interface
The idle disconnect timer on a demand-dial interface controls how long it stays up with no traffic; increasing this value prevents premature disconnection.
Question 2: After adding a new subnet (192.168.50.0/24) to the network, clients on that subnet cannot communicate with other subnets. The DHCP server has a new scope for 192.168.50.0/24 and clients receive correct addresses. What is missing?
- A DHCP relay agent on the new subnet's router interface
- A static route on the core router pointing to 192.168.50.0/24 (Correct answer)
- A DHCP exclusion for the router's interface address
- An additional IP address on the DHCP server NIC
Correct answer: A static route on the core router pointing to 192.168.50.0/24
Routers need a routing table entry for the new subnet to forward traffic to and from 192.168.50.0/24; without it, packets destined for the new subnet are dropped.
Question 3: An administrator configures Windows Server 2008 R2 as a RADIUS proxy to forward authentication requests to two backend NPS servers. One NPS server processes requests; the other never receives any. What should the administrator configure?
- Set equal priority and weight on both RADIUS servers in the remote RADIUS server group (Correct answer)
- Enable RADIUS accounting on the second NPS server
- Configure a separate connection request policy for each NPS server
- Add the second NPS server as a RADIUS client on the proxy
Correct answer: Set equal priority and weight on both RADIUS servers in the remote RADIUS server group
Remote RADIUS server groups load-balance based on priority and weight; equal settings distribute requests across all servers in the group.
Question 4: A Windows Server 2008 R2 DNS server experiences increased query load after a major website hosted on the network gains popularity. Which DNS server feature reduces repeated recursive lookups for the same external names?
- DNS caching with appropriately sized cache and respected TTLs (Correct answer)
- Increasing the number of zone transfer intervals
- Enabling DNS round-robin for the popular website's A records
- Configuring a secondary zone for the popular website's domain
Correct answer: DNS caching with appropriately sized cache and respected TTLs
DNS caching stores resolved query results for the duration of their TTL, so repeated queries for the same name are answered locally without additional recursion.
Question 5: A company uses IPsec transport mode to secure traffic between two Windows Server 2008 R2 servers. After upgrading one server's network adapter, encrypted traffic fails. Unencrypted traffic between the servers works. What should the administrator check?
- Whether the new adapter's TCP Chimney Offload is interfering with IPsec processing
- Whether the IPsec policy still references the old adapter's IP address (Correct answer)
- Whether the new adapter supports Jumbo Frames required for IPsec
- Whether the server's firewall blocks IKE traffic on UDP port 500
Correct answer: Whether the IPsec policy still references the old adapter's IP address
IPsec policies can be bound to specific IP addresses; if the new adapter has a different IP, the existing policy may not apply and IPsec negotiation will fail.
Question 6: Clients report that after obtaining a DHCP lease, they occasionally get an APIPA address (169.254.x.x) instead of a valid lease. The DHCP server has available addresses. What is the most likely cause?
- The DHCP server is not authorized in Active Directory
- Network congestion is causing DHCPOFFER packets to be lost before the client's timeout (Correct answer)
- The DHCP scope has an incorrect subnet mask
- The client's DHCP service is set to manual start
Correct answer: Network congestion is causing DHCPOFFER packets to be lost before the client's timeout
APIPA is assigned when a client sends DHCPDISCOVER but receives no DHCPOFFER; packet loss due to network congestion can cause this intermittently.
Question 7: A Windows Server 2008 R2 server is configured as a DNS server with root hints. Clients report that some external names resolve slowly or fail occasionally. The server has internet access. What is the best first step to improve reliability?
- Configure forwarders pointing to reliable public DNS servers such as the ISP's resolvers (Correct answer)
- Increase the DNS server's query timeout value
- Add more root hint servers to the list
- Enable DNS over TCP for all queries
Correct answer: Configure forwarders pointing to reliable public DNS servers such as the ISP's resolvers
Configuring forwarders delegates external resolution to reliable upstream resolvers, reducing latency and reliance on direct root server queries.
MCTS 70-642 Case Studies & Practical Application 4
A Windows Server 2008 R2 server running the Routing and Remote Access role is configured for demand-dial routing.
The demand-dial interface connects successfully but drops after exactly 5 minutes of idle time.
How should the administrator fix this?