AP Networking DHCP Leases and Relays Practice Test

1. Relinquish a previously leased address
2. Renew an existing unexpired assignment
3. Confirm a specific offer already selected
4. A DHCP server willing to offer configuration

Correct answer: D. A DHCP server willing to offer configuration

Discovery begins the initial DHCP exchange. It asks for configuration rather than resolving a hostname or testing an application.

1. DHCPOFFER
2. DHCPACK
3. DHCPNAK
4. DHCPREQUEST

Correct answer: A. DHCPOFFER

An offer proposes configuration. The client still requests its chosen offer and needs an acknowledgement before using the assignment normally.

1. DHCPINFORM
2. DHCPREQUEST
3. DHCPDECLINE
4. DHCPDISCOVER

Correct answer: B. DHCPREQUEST

The selecting client broadcasts a request that identifies its chosen server and requested address, allowing other offering servers to withdraw their offers.

1. DHCPACK
2. DHCPNAK
3. DHCPOFFER
4. DHCPINFORM

Correct answer: A. DHCPACK

An acknowledgement confirms the assignment and its parameters. An offer alone is not the completed allocation.

1. The time a TCP session must stay open
2. The switch's MAC aging interval
3. How long the client may use the assignment without extending it
4. The resolver's positive cache lifetime

Correct answer: C. How long the client may use the assignment without extending it

A lease is a time-limited address assignment. The client must renew or stop using it when the valid lease expires.

1. The domain name server option
2. The router option
3. The subnet mask option alone
4. The server identifier alone

Correct answer: B. The router option

The router option commonly supplies a default gateway. A leased address does not by itself establish the correct off-subnet next hop.

1. Which server offered the longest lease
2. Which recursive resolver to query
3. Which transport listener is open
4. Whether a destination is on its local IP subnet

Correct answer: D. Whether a destination is on its local IP subnet

The address and mask determine the local subnet comparison. The client then uses a local neighbor or an appropriate route.

1. A supported way to relay the client broadcast exchange to that server
2. A public hostname for the DHCP server before client discovery
3. A longer lease on unconfigured clients
4. A web listener on the router

Correct answer: A. A supported way to relay the client broadcast exchange to that server

Ordinary routers do not simply route the initial client broadcast to a remote server. An intended relay path or a suitable local server is needed.

1. Only a list of active DNS aliases
2. A pool and settings for a client subnet
3. Only a table of switch MAC locations
4. Only the server's management address

Correct answer: B. A pool and settings for a client subnet

A scope groups address allocation and associated settings for a network. Relay and server selection must match the intended client subnet.

1. To avoid leasing that same address to another endpoint
2. To stop all DHCP clients using the printer's gateway
3. To make the printer obtain a different address on every reboot
4. To prevent the printer from sending ARP

Correct answer: A. To avoid leasing that same address to another endpoint

Exclusions prevent overlapping assignment. The printer's static configuration must still fit the subnet and gateway design.

1. A static address with all DHCP configuration disabled
2. A randomly selected address with a shorter lease
3. A DNS alias without a server allocation rule
4. A correctly matched reservation on the DHCP server

Correct answer: D. A correctly matched reservation on the DHCP server

A reservation retains DHCP configuration delivery while directing the identified client to the intended address. Verify the matching identity and nonconflicting ownership.

1. The client necessarily has a working off-subnet default route
2. The server's scope necessarily contains that link-local range
3. It has selected an IPv4 link-local address; investigate the missing DHCP assignment
4. The approved server necessarily acknowledged that address

Correct answer: C. It has selected an IPv4 link-local address; investigate the missing DHCP assignment

IPv4 link-local selection can follow failure to obtain usable configuration. It is evidence about local configuration, not proof of the specific DHCP failure cause.

1. DHCPINFORM
2. DHCPRELEASE
3. DHCPREQUEST
4. DHCPDECLINE

Correct answer: B. DHCPRELEASE

A release tells the server the client is giving up the assignment. Servers still need lease expiration handling for clients that disappear without releasing.

1. DHCPNAK
2. DHCPINFORM
3. DHCPRELEASE
4. DHCPDECLINE

Correct answer: D. DHCPDECLINE

A decline reports that the assigned address appears occupied. Investigate conflicting ownership rather than repeatedly handing out the same address.

1. A statement that a DNS name is absent
2. A successful extension of the requested lease
3. A proposed offer that the client may select normally
4. The request cannot be accepted as valid by the responding server

Correct answer: D. The request cannot be accepted as valid by the responding server

A negative acknowledgement rejects the requested configuration. The client must return to address acquisition rather than treat it as an ACK.

1. They guarantee the supplied options are approved
2. They replace checking the client's effective mask
3. They prove the required application completed
4. They help attribute the configuration to the server that supplied it

Correct answer: D. They help attribute the configuration to the server that supplied it

Attribution distinguishes legitimate and unexpected server responses. It supports comparison with the approved address plan.

1. The client must always move to a different subnet
2. The assignment becomes permanent static configuration
3. The client's lease timing is extended according to the acknowledged assignment
4. The server automatically clears every other lease

Correct answer: C. The client's lease timing is extended according to the acknowledged assignment

Renewal extends the assignment when accepted. It does not inherently replace hardware identity or control all network routes.

1. A reservation removes all address-acquisition messages
2. A reservation guarantees unique ownership outside DHCP
3. A reservation still obtains its assignment through DHCP
4. A manually set address always uses the server's lease timer

Correct answer: C. A reservation still obtains its assignment through DHCP

A reserved client uses DHCP; a manually configured endpoint does not need a DHCP address lease. Both require a nonconflicting address plan.

1. Only the client hostname without interface context
2. Only the server's saved scope configuration
3. Only an old capture from a different attachment
4. The client interface and network where the exchange was observed

Correct answer: D. The client interface and network where the exchange was observed

DHCP is tied to the client's attachment and address context. A trace from a different interface may not represent the failed allocation.

1. The server must reject every renewal even for current owners
2. The scope automatically grows beyond its configured subnet
3. Every valid existing lease immediately expires
4. New clients may receive no usable offer from that pool

Correct answer: D. New clients may receive no usable offer from that pool

Scope exhaustion limits new allocation. Current valid leases can continue, so the affected cohort and timing matter.

1. The router option
2. The lease time option
3. The domain name server option
4. The server identifier option alone

Correct answer: C. The domain name server option

The DNS server option supplies resolver addresses. That configuration still needs reachability and correct resolution policy.

1. DHCPRELEASE
2. DHCPDECLINE
3. DHCPREQUEST for a new allocation
4. DHCPINFORM

Correct answer: D. DHCPINFORM

DHCPINFORM requests configuration parameters for an externally configured address. It is not a new dynamic address lease.

1. The acknowledged settings and downstream paths must still be valid
2. Every acknowledged lease proves the gateway forwards all traffic
3. The assigned settings are always correct because a server sent them
4. The ACK necessarily includes a completed application transaction

Correct answer: A. The acknowledged settings and downstream paths must still be valid

DHCP completes configuration allocation. Gateway forwarding, DNS and the required service are separate checks.

1. To prevent static endpoints from conflicting automatically
2. To replace the need for client identity fields
3. To correlate leases with events and other observations
4. To make every DHCP address permanent

Correct answer: C. To correlate leases with events and other observations

Time correlation supports reliable attribution. Accurate clocks do not by themselves eliminate overlapping allocations.

1. The server's lease expiration handling
2. The resolver cache TTL expiring
3. The switch's MAC entry aging out
4. The application session ending

Correct answer: A. The server's lease expiration handling

DHCP cannot depend on every client releasing cleanly. Lease lifetime limits abandoned allocations.

1. Seven hours after start
2. Four hours after the lease starts
3. Eight hours after start
4. One hour after start

Correct answer: B. Four hours after the lease starts

The default T1 is half the lease duration. Default T2 is later, at seven eighths, and expiration is a separate boundary.

1. Four hours after start
2. Seven hours after the lease starts
3. Eight hours after start
4. Eight minutes after start

Correct answer: B. Seven hours after the lease starts

Default T2 is 0.875 of the lease duration: eight times 0.875 equals seven hours. The client still has one hour of validity remaining.

1. Every DHCP server by broadcast immediately at T1
2. The server that granted the lease, normally by unicast
3. Only the relay's management interface regardless of server
4. Only whichever server last answered a DNS query

Correct answer: B. The server that granted the lease, normally by unicast

A renewing client first attempts its original server. If this fails until T2, rebinding broadens the attempt.

1. The client releases the lease and never requests again
2. The client broadcasts a DHCPREQUEST so an available server can respond
3. The client permanently pins the original server without rebinding
4. The client continues the old lease indefinitely

Correct answer: B. The client broadcasts a DHCPREQUEST so an available server can respond

Rebinding seeks a server able to extend valid configuration. It differs from both original-server renewal and expired-lease use.

1. Extend it locally by the previous duration
2. Treat it as a permanent reservation
3. Stop using it and seek valid configuration
4. Keep using it until the user signs out

Correct answer: C. Stop using it and seek valid configuration

A client cannot authorize its own lease extension. Expiration ends the assignment's validity unless a new valid lease is obtained.

1. 5
2. 15
3. 50
4. 25

Correct answer: A. 5

The inclusive range has 50 addresses. Subtract ten exclusions and 35 leases: five remain available.

1. The client hostname option alone
2. The DNS server option alone
3. giaddr, the relay agent address field
4. The lease time option alone

Correct answer: C. giaddr, the relay agent address field

The relay address identifies the client-side network for allocation and reply delivery. The server needs the matching scope and a return path.

1. The browser's certificate store
2. Only the router option printed by one client
3. The DNS server's authority role
4. The client-facing relay address and the server's scope selection

Correct answer: D. The client-facing relay address and the server's scope selection

A relay or scope-selection error can misidentify the client subnet. Compare the actual giaddr and configured pool before changing endpoint masks individually.

1. Every offer in the trace was accepted
2. The client must use both offered addresses simultaneously
3. The first offer necessarily became the effective lease
4. The client chose a different offer; the first OFFER alone was not its final assignment

Correct answer: D. The client chose a different offer; the first OFFER alone was not its final assignment

Initial selection identifies the chosen server. Follow the same client and transaction through request and acknowledgement.

1. Trace server-to-relay-to-client reply delivery
2. Increase lease duration without checking return delivery
3. Clear every active lease despite the observed ACK
4. Replace only the DNS option

Correct answer: A. Trace server-to-relay-to-client reply delivery

Server transmission is not endpoint receipt. Check relay reply handling, intervening policy and the local broadcast or unicast delivery.

1. Correct the scope's router option and verify newly applied client settings
2. Treat a valid address as proof that the gateway option is valid
3. Change only the client's hostname
4. Clear resolver cache without changing the router option

Correct answer: A. Correct the scope's router option and verify newly applied client settings

A faulty router option can prevent off-subnet reachability despite a successful lease. Verify the effective client configuration after the repair.

1. The reservation's matching identity and the new client's identifier or hardware identity
2. Only the scope duration
3. Only the configured DNS addresses
4. Only the reserved hostname label

Correct answer: A. The reservation's matching identity and the new client's identifier or hardware identity

Reservation behavior depends on the server's matching rule. A replaced NIC or changed client identifier can break that match.

1. Attribute every ACK on the segment to that laptop
2. Do not attribute it to the affected client without the matching identity and context
3. Attribute it solely by transaction ID regardless of client
4. Treat the latest ACK as the affected client's without context

Correct answer: B. Do not attribute it to the affected client without the matching identity and context

Transaction identifiers help match an exchange but are not permanent globally unique endpoint identities. Include client identity, interface and time.

1. Check discovery and relay delivery specifically from VLAN 70
2. Delete all leases before observing that VLAN's request
3. Change DNS settings on every VLAN
4. Assume the entire server is off despite other successful allocations

Correct answer: A. Check discovery and relay delivery specifically from VLAN 70

The working leased clients and available pool narrow the issue toward that VLAN's allocation path. Verify each DHCP stage there.

1. A DHCPNAK followed by fresh acquisition for the new subnet
2. A permanent right to retain the old subnet's address
3. A silent extension of the old lease despite rejection
4. Automatic use of the same gateway on every network

Correct answer: A. A DHCPNAK followed by fresh acquisition for the new subnet

Clients can attempt to validate remembered configuration after moving. A rejected old assignment requires new valid configuration.

1. How this server accounts for reserved addresses and current allocation state
2. Only the inclusive range size
3. Only the number of currently connected devices
4. Only the reservation count without overlaps or state

Correct answer: A. How this server accounts for reserved addresses and current allocation state

Servers may represent reserved capacity differently. Use the effective allocation rules and state, not range size alone.

1. Only the configured scope label
2. Only one successful public lookup
3. Only the presence of an approved server process
4. Captured offers and chosen ACK tied to each server identifier and supplied options

Correct answer: D. Captured offers and chosen ACK tied to each server identifier and supplied options

Compare the actual competing offers and selected assignment. Correct-looking address syntax does not make a gateway trustworthy.

1. Its offers or acknowledgements can be dropped by the switch
2. All client discoveries must be blocked by definition
3. Every statically addressed endpoint must change IP
4. The switch automatically promotes the server port to trusted

Correct answer: A. Its offers or acknowledgements can be dropped by the switch

Snooping trust configuration controls where server-originated messages are accepted. Validate the actual deployment path before changing trust.

1. The port's trust means the endpoint may run an approved server
2. The port must be trusted before a client can receive any lease
3. It should not be accepted as a source of DHCP server replies
4. The port must reject all client discovery messages

Correct answer: C. It should not be accepted as a source of DHCP server replies

An untrusted client port can carry legitimate client DHCP traffic while server messages are restricted. Trust means a server-message source, not general client permission.

1. Availability of the intended server configuration row
2. The configured identity match existing in the reservation
3. Freedom from independently configured address conflicts
4. The reserved value stored on the server

Correct answer: C. Freedom from independently configured address conflicts

DHCP allocation cannot prevent an independent endpoint from manually claiming an address. Check actual ownership as well as pool bookkeeping.

1. Only the common DHCP hostname
2. Only the laptop's previously remembered lease
3. The selected DHCP server, options and attachment for each interface
4. Only the identical browser version

Correct answer: C. The selected DHCP server, options and attachment for each interface

Different interfaces can attach to different VLANs and servers. Compare effective assignments rather than treating the laptop as one allocation path.

1. Updating one authoritative record changes every client's resolver option
2. DHCP edits immediately push new options to all clients
3. They have not yet received and applied updated DHCP configuration
4. Old option values are permanently fixed in hardware

Correct answer: C. They have not yet received and applied updated DHCP configuration

A server-side change does not instantly replace every client's effective settings. Verify renewal or an approved reacquisition and the resulting configuration.

1. UDP client 67 and server 68
2. UDP client 53 and server 53
3. TCP client 68 and server 67
4. UDP client 68 and server 67

Correct answer: D. UDP client 68 and server 67

DHCPv4 uses UDP 67 and 68 for its normal server/client exchange. Relay-path policy must fit the actual packet direction and addressing.

1. It does not repair the demonstrated missing discovery path and can disrupt allocation state
2. It corrects giaddr on every relay automatically
3. It is necessary whenever discoveries are absent at the server
4. It guarantees request delivery after a database reset

Correct answer: A. It does not repair the demonstrated missing discovery path and can disrupt allocation state

Evidence points to transport from client to server. Preserve valid state while tracing the missing exchange.

1. The DNS search list establishes the client's VLAN
2. A valid DHCP response may still come from an unintended attachment or scope
3. The intended switch configuration proves effective attachment
4. A received ACK guarantees intended VLAN membership

Correct answer: B. A valid DHCP response may still come from an unintended attachment or scope

The assignment and effective network attachment must agree. A completed exchange can allocate configuration from the wrong network.

1. Continue the assignment after its acknowledged expiration
2. Renew at 11:00, rebind at 13:00, stop using the lease at 14:00
3. Rebind before renewing because T2 is later
4. Renew at the default times despite the explicit timer options

Correct answer: B. Renew at 11:00, rebind at 13:00, stop using the lease at 14:00

Explicit valid timer values override defaults. Convert seconds to one and three hours, retaining the four-hour expiration boundary.

1. Client transmission of the already-observed discovery
2. Scope selection already demonstrated by the recorded reply
3. Server receipt of the already-observed request
4. Relay receipt and delivery of those replies onto the client network

Correct answer: D. Relay receipt and delivery of those replies onto the client network

The observations already establish the request path and server reply generation. Trace the remaining return stages with the same transaction and client identity.

1. 29 addresses
2. 50 addresses
3. 30 addresses
4. 42 addresses

Correct answer: C. 30 addresses

The inclusive range has 200 addresses. Effective unavailable entries total 170, leaving 30. The disjoint condition prevents double subtraction.

1. The server's outage instantly canceled every client lease
2. The existing assignment remained valid until expiry, then could not be extended
3. The client permanently converted the lease to static use
4. All clients must stop at T1 even while their lease is valid

Correct answer: B. The existing assignment remained valid until expiry, then could not be extended

Server availability and current lease validity are different. A renewal-path problem can become visible only as clients exhaust their remaining validity.

1. Clients always reject one of the servers before either allocates
2. Different server identifiers guarantee disjoint allocations
3. A reservation on A automatically reserves the same entry on B
4. Each can lease an address the other has already assigned

Correct answer: D. Each can lease an address the other has already assigned

Independent overlapping allocation lacks shared ownership state. Use a supported coordinated design or correctly separated allocation rather than assuming mutual awareness.

1. Change only the reachable server's display name
2. Treat server reachability as proof that pool selection is correct
3. Correct the client-subnet identification or provide the intended matching scope
4. Expand an unrelated scope while retaining the incorrect identification

Correct answer: C. Correct the client-subnet identification or provide the intended matching scope

Server reachability alone does not identify the correct allocation network. The relay information must match the intended client scope.

1. Permit only the small reply size and declare complete recovery
2. Blame exhaustion despite the received offers
3. Clear all leases without examining reply delivery
4. Reply sizes, fragmentation or path limits, and actual drops on the return path

Correct answer: D. Reply sizes, fragmentation or path limits, and actual drops on the return path

Size-dependent behavior calls for packet and policy evidence on that path. Avoid removing all filtering before finding the constrained or discarded packet.

1. No; confirm the effective IP network rather than assume every radio roam changes it
2. Yes, every AP roam requires a new IPv4 subnet
3. Yes, an unchanged VLAN forces a different client identifier
4. No, no radio roam can ever change IP attachment

Correct answer: A. No; confirm the effective IP network rather than assume every radio roam changes it

A radio attachment change and an IP-network change are separate events. Verify actual VLAN and address context before requiring fresh allocation.

1. The SSID text grants permanent use of every old lease
2. The actual subnet and lease validity, not the SSID label, determine address suitability
3. The remembered gateway remains valid on every similarly named network
4. The old server identifier proves current subnet suitability

Correct answer: B. The actual subnet and lease validity, not the SSID label, determine address suitability

Wireless network names do not prove identical IP attachment. Validate the remembered assignment against the network actually reached.

1. Every endpoint automatically discards its acknowledged lease after rollback
2. The server's free count alone proves current address ownership
3. The switch reconciles abandoned server state without DHCP evidence
4. The server may reallocate addresses that those endpoints still validly use

Correct answer: D. The server may reallocate addresses that those endpoints still validly use

Allocation state and endpoint lease state can diverge. Reconcile ownership using the supported recovery procedure before treating apparently free addresses as safe.

1. Selection of a newly received offer with a selected server identifier
2. Validation of the remembered configuration on the current network
3. A release of the remembered assignment before validation
4. Renewal unicast to the original server in every case

Correct answer: B. Validation of the remembered configuration on the current network

INIT-REBOOT checks previously known configuration. Distinguish this from SELECTING, RENEWING and REBINDING using message fields and client state.

1. Change lease length without examining the renewal route
2. Use discovery success as proof of direct unicast renewal
3. Test only server loopback allocation
4. The direct renewal path from the relayed initial broadcast path

Correct answer: D. The direct renewal path from the relayed initial broadcast path

Successful relayed allocation does not prove every client's unicast renewal route and policy. Test both states and their actual addressing.

1. Delete all legitimate leases while leaving the generator running
2. Assume every identity represents a separate physical endpoint
3. Stop the approved test workload and investigate its allocation behavior before resizing the production pool
4. Double the pool before checking the test tool's behavior

Correct answer: C. Stop the approved test workload and investigate its allocation behavior before resizing the production pool

Lease consumption can reflect client identity behavior rather than genuine endpoint growth. Preserve legitimate assignments and correct the test process before capacity changes.

1. Identical hostnames are required for the server to confuse them
2. Different switch ports always override the configured server identity key
3. The server identifier uniquely distinguishes every requesting client
4. The server's chosen identity key cannot uniquely distinguish those clients

Correct answer: D. The server's chosen identity key cannot uniquely distinguish those clients

Check the actual server matching rule. Duplicate identity inputs can make distinct machines appear to be one allocating client.

1. Permit the intended relay-server exchange with its real endpoints and ports
2. Permit every UDP source without limiting the relay exchange
3. Permit only the original client address on the server-side boundary
4. Allow the opposite reply direction and leave the request blocked

Correct answer: A. Permit the intended relay-server exchange with its real endpoints and ports

Policy must model the relay path actually used. Scope the correction to intended DHCP exchange and retain unrelated restrictions.

1. Inventory and test both DHCP-managed and statically configured endpoints
2. Use the saved server option as proof of all effective client settings
3. Assume static controllers consume the changed DHCP mask
4. Verify only newly leased endpoints

Correct answer: A. Inventory and test both DHCP-managed and statically configured endpoints

DHCP controls clients that consume its configuration. A mixed estate needs explicit treatment and verification of static devices.

1. 20:00
2. 09:00 the following day
3. 13:00
4. 17:00

Correct answer: A. 20:00

A successful renewal starts the acknowledged new lifetime. Eight hours after 12:00 is 20:00; the original expiration is superseded.

1. Release all declined addresses without checking claimants
2. Extend lease duration as a substitute for attribution
3. Actual address ownership, overlapping pools and static assignments on the merged segment
4. Disable conflict reports while retaining overlapping ownership

Correct answer: C. Actual address ownership, overlapping pools and static assignments on the merged segment

Repeated conflict reports indicate allocation and ownership need review. Avoid disabling conflict handling to conceal duplicate use.

1. Use the MAC table alone as complete lease state
2. Apply dependent enforcement before validating required bindings
3. Assume all earlier leases were imported into the binding table
4. How valid bindings are learned or restored in this implementation before relying on enforcement

Correct answer: D. How valid bindings are learned or restored in this implementation before relying on enforcement

Enforcement dependent on binding state needs a supported state acquisition or recovery path. Do not assume preexisting leases populate it retrospectively.

1. The new relay identifier necessarily preserves the old policy match
2. The server's relay-information policy now matches the changed circuit values incorrectly
3. The circuit information can affect only DNS answers
4. Any received offer proves the intended circuit group

Correct answer: B. The server's relay-information policy now matches the changed circuit values incorrectly

Relay metadata can influence allocation policy in configured deployments. Compare the received values with the actual intended attachment and server rules.

1. That earlier clients may retain their acknowledged timers
2. That migration must account for effective client state
3. That later acknowledgements can apply the new duration
4. That the edit instantly invalidates or shortens every earlier acknowledged lease

Correct answer: D. That the edit instantly invalidates or shortens every earlier acknowledged lease

Configuration changes do not retroactively prove all existing client lease timers changed. Plan migration around effective acknowledged state.

1. 8 addresses
2. 12 addresses
3. 20 addresses
4. 48 addresses

Correct answer: A. 8 addresses

There are 12 free addresses. Twenty additional clients need eight more usable slots, subject to the subnet's real address and exclusion limits.

1. A general promise that all pairs behave identically during partition
2. A single allocation while both servers are healthy
3. A count of two configured servers
4. The specific supported partition behavior, address ownership rules and tested client outcomes

Correct answer: D. The specific supported partition behavior, address ownership rules and tested client outcomes

Coordination details determine how partitioned servers allocate safely and resume operation. Test the supported failure mode rather than promise universal availability.

1. An ACK from any source proves the approved assignment
2. The last visible ACK always wins regardless of client state
3. The first visible ACK always proves final effective state
4. The actual client state, selected exchange and resulting applied settings

Correct answer: D. The actual client state, selected exchange and resulting applied settings

Correlate state and transaction fields with effective endpoint configuration. Multiple observed responses need attribution, not a simplistic first-or-last rule.

1. Verify only relay management ping
2. Repeat only the same initial discovery
3. Inspect only the server's saved pool definition
4. Verify renewal, rebinding when required, and correct effective options for representative clients

Correct answer: D. Verify renewal, rebinding when required, and correct effective options for representative clients

A complete test covers the relevant client states and applied settings. New allocation alone does not establish lifecycle recovery.