Question 700
A network team addresses this situation: Users resolve app.example.net to an old address that no longer hosts the service, while direct new-IP connections work. After the corrective action, which test or result BEST verifies that the problem is resolved?
- Renew multiple new clients and inspect free address count.
- Inspect server-side relay packets from that VLAN.
- Inspect the port VLAN and renew the intended sales DHCP lease.
- Query authoritative and recursive records and retest hostname connection.
Explanation
Correct Answer
D:Correct answers and service connection validate DNS repair.
Incorrect Answers
A:Renew multiple new clients and inspect free address count. That check cannot demonstrate query authoritative and recursive records and retest hostname connection.
B:VLAN membership and 802.1Q tagging determine which Layer 2 broadcast domain carries each frame. That check cannot demonstrate query authoritative and recursive records and retest hostname connection.
C:DHCP assigns client network parameters through a supported lease exchange. That check cannot demonstrate query authoritative and recursive records and retest hostname connection.
Question 701
A network specialist investigates this evidence: Users resolve app.example.net to an old address that no longer hosts the service, while direct new-IP connections work. Which underlying condition BEST explains the observed failure or requirement?
- The authoritative A record is stale.
- The DHCP address pool has no usable remaining leases.
- The VLAN's router interface lacks a DHCP relay destination.
- The oversized mask causes an incorrect on-link decision.
Explanation
Correct Answer
A:The authoritative A record is stale. Name resolution is sending clients to the wrong IPv4 destination.
Incorrect Answers
B:DHCP assigns client network parameters through a supported lease exchange. That does not establish the authoritative A record is stale.
C:Communication between different IP subnets requires a routed interface or gateway rather than Layer 2 bridging alone. The missing change involves the authoritative A record is stale.
D:The oversized mask causes an incorrect on-link decision. That does not establish the authoritative A record is stale.
Question 702
A network team observes: An alias references another alias that points back to the first, causing resolution failure. What is the MOST appropriate corrective action or technical decision?
- Update the A record and manage resolver cache TTL during migration.
- Remove the alias loop and point the chain to a valid canonical hostname.
- Correct the DHCP router option to the actual local gateway.
- Set controlled root priorities and appropriate BPDU guard/root guard.
Explanation
Correct Answer
B:A CNAME chain must eventually resolve to address data. Circular cname configuration prevents a terminal address resolution.
Incorrect Answers
A:Updating the A record and managing resolver cache TTL during migration would not remove the alias loop and point the chain to a valid canonical hostname.
C:Correcting the DHCP router option to the actual local gateway would not remove the alias loop and point the chain to a valid canonical hostname.
D:Setting controlled root priorities and appropriate BPDU guard/root guard would not remove the alias loop and point the chain to a valid canonical hostname.
Question 703
A network team addresses this situation: An alias references another alias that points back to the first, causing resolution failure. After the corrective action, which test or result BEST verifies that the problem is resolved?
- Query authoritative and recursive records and retest hostname connection.
- Inspect server-side relay packets from that VLAN.
- Trace the alias chain with dig and confirm final A or AAAA records.
- Capture SYN and SYN-ACK on both sides of the filtering point.
Explanation
Correct Answer
C:Trace the alias chain with dig and confirm final A or AAAA records.
Incorrect Answers
A:Correct answers and service connection validate DNS repair. That check cannot demonstrate trace the alias chain with dig and confirm final A or AAAA records.
B:VLAN membership and 802.1Q tagging determine which Layer 2 broadcast domain carries each frame. That check cannot demonstrate trace the alias chain with dig and confirm final A or AAAA records.
D:TCP connections require an accepted SYN, SYN-ACK and ACK exchange before application requests. That check cannot demonstrate trace the alias chain with dig and confirm final A or AAAA records.
Question 704
A network specialist investigates this evidence: An alias references another alias that points back to the first, causing resolution failure. Which underlying condition BEST explains the observed failure or requirement?
- The authoritative A record is stale.
- An uncontrolled Layer 2 loop produces repeated frames.
- Duplicate host addressing causes ARP instability.
- Circular CNAME configuration prevents a terminal address resolution.
Explanation
Correct Answer
D:Circular CNAME configuration prevents a terminal address resolution. A CNAME chain must eventually resolve to address data.
Incorrect Answers
A:Name resolution is sending clients to the wrong IPv4 destination. That does not establish circular CNAME configuration prevents a terminal address resolution.
B:An uncontrolled Layer 2 loop produces repeated frames. That does not establish circular CNAME configuration prevents a terminal address resolution.
C:One IP cannot reliably identify two simultaneous hosts. That does not establish circular CNAME configuration prevents a terminal address resolution.
Question 705
A network team observes: Clients in a new VLAN never receive leases, but same-LAN users next to the DHCP server work. What is the MOST appropriate corrective action or technical decision?
- Add the correct IP helper to forward DHCP requests to the server.
- Correct access VLAN membership to VLAN 30.
- Permit VLAN 90 on approved trunk ports with consistent tagging.
- Install the appropriate upstream default route with healthy next hop.
Explanation
Correct Answer
A:Routed interfaces do not pass client broadcasts without relay. The vlan's router interface lacks a dhcp relay destination.
Incorrect Answers
B:Correcting access VLAN membership to VLAN 30 would not add the correct IP helper to forward DHCP requests to the server.
C:Permitting VLAN 90 on approved trunk ports with consistent tagging would not add the correct IP helper to forward DHCP requests to the server.
D:Installing the appropriate upstream default route with healthy next hop would not add the correct IP helper to forward DHCP requests to the server.
Question 706
A network team addresses this situation: Clients in a new VLAN never receive leases, but same-LAN users next to the DHCP server work. After the corrective action, which test or result BEST verifies that the problem is resolved?
- Check route and ping gateway then a remote address.
- Inspect server-side relay packets from that VLAN.
- Query authoritative and recursive records and retest hostname connection.
- Inspect the port VLAN and renew the intended sales DHCP lease.
Explanation
Correct Answer
B:VLAN membership and 802.1Q tagging determine which Layer 2 broadcast domain carries each frame. Verification of this result involves inspecting server-side relay packets from that VLAN.
Incorrect Answers
A:Communication between different IP subnets requires a routed interface or gateway rather than Layer 2 bridging alone. Verification of this result involves inspecting server-side relay packets from that VLAN.
C:Correct answers and service connection validate DNS repair. That check cannot demonstrate correct switch VLAN and trunk classification.
D:DHCP assigns client network parameters through a supported lease exchange. Verification of this result involves inspecting server-side relay packets from that VLAN.
Question 707
A network team observes: A DHCP server offers a gateway address already statically assigned to a firewall. What is the MOST appropriate corrective action or technical decision?
- Assign unique addresses and correct reservations in IPAM.
- Correct the DHCP router option to the actual local gateway.
- Exclude the gateway address and clear conflicting leases safely.
- Add the correct IP helper to forward DHCP requests to the server.
Explanation
Correct Answer
C:Static network addresses must not be issued dynamically. Infrastructure address was not excluded from the scope.
Incorrect Answers
A:Assigning unique addresses and correcting reservations in IPAM would not exclude the gateway address and clear conflicting leases safely.
B:Correcting the DHCP router option to the actual local gateway would not exclude the gateway address and clear conflicting leases safely.
D:Adding the correct IP helper to forward DHCP requests to the server would not exclude the gateway address and clear conflicting leases safely.
Question 708
A network team addresses this situation: A DHCP server offers a gateway address already statically assigned to a firewall. After the corrective action, which test or result BEST verifies that the problem is resolved?
- Observe ARP mappings stabilize and both printers respond on unique IPs.
- Inspect server-side relay packets from that VLAN.
- Check route and ping gateway then a remote address.
- Request several leases and confirm gateway never appears in offers.
Explanation
Correct Answer
D:Communication between different IP subnets requires a routed interface or gateway rather than Layer 2 bridging alone. Verification of this result involves request several leases and confirm gateway never appears in offers.
Incorrect Answers
A:A forwarded frame uses the local next-hop MAC even when its encapsulated IP destination stays constant. That check cannot demonstrate an authorized inter-subnet routed path.
B:VLAN membership and 802.1Q tagging determine which Layer 2 broadcast domain carries each frame. Verification of this result involves request several leases and confirm gateway never appears in offers.
C:Communication between different IP subnets requires a routed interface or gateway rather than Layer 2 bridging alone. Verification of this result involves request several leases and confirm gateway never appears in offers. The observed condition is a network team addresses this situation: A DHCP server offers a gateway address already statically assigned to a firewall. After the corrective action,.
Question 709
A network specialist investigates this evidence: A DHCP server offers a gateway address already statically assigned to a firewall. Which underlying condition BEST explains the observed failure or requirement?
- Infrastructure address was not excluded from the scope.
- Duplicate host addressing causes ARP instability.
- Default-gateway address is not a reachable local next hop.
- The VLAN's router interface lacks a DHCP relay destination.
Explanation
Correct Answer
A:Infrastructure address was not excluded from the scope. Static network addresses must not be issued dynamically.
Incorrect Answers
B:One IP cannot reliably identify two simultaneous hosts. That does not establish successful client IP addressing from the correct scope.
C:IP routing depends on a route to the destination prefix and a reachable next hop. That does not establish successful client IP addressing from the correct scope.
D:Communication between different IP subnets requires a routed interface or gateway rather than Layer 2 bridging alone. The missing change involves infrastructure address was not excluded from the scope.
Question 710
A network team observes: A new unmanaged access switch causes frequent root bridge changes and spanning-tree reconvergence. What is the MOST appropriate corrective action or technical decision?
- Find the added loop and restore spanning-tree protection.
- Set controlled root priorities and appropriate BPDU guard/root guard.
- Expand the subnet scope or reclaim expired reservations after planning.
- Correct access VLAN membership to VLAN 30.
Explanation
Correct Answer
B:Root guard prevents unauthorized switches becoming topology root. Root election is not protected from inferior edge equipment.
Incorrect Answers
A:Finding the added loop and restoring spanning-tree protection would not set controlled root priorities and appropriate BPDU guard/root guard. Root guard prevents unauthorized switches becoming topology root.
C:Expanding the subnet scope or reclaim expired reservations after planning would not set controlled root priorities and appropriate BPDU guard/root guard.
D:Correcting access VLAN membership to VLAN 30 would not set controlled root priorities and appropriate BPDU guard/root guard. Root guard prevents unauthorized switches becoming topology root.
CompTIA Network+ (N10-009) Practice Tests