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Topic: DHCPSwitch
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1.0 Network Infrastructure and Connectivity

DHCP Practice Questions

DHCP server configuration, relay, and lease behavior.

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One solved question, so you can see how these are marked

Which command configures a router's own interface to obtain its IP address dynamically from an upstream DHCP server, rather than using a static address?

ip address dhcp

ip address dhcp is entered under an interface to make that interface act as a DHCP client, requesting and using an address handed out by a DHCP server instead of a fixed configured address.

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Find related practice in the CCNA path
All 9 DHCP questions in this set

Answers and explanations appear when you work through the set above.

  1. Which command on a router configured as a DHCP client shows the lease details it received, including the DHCP server's address and lease timers?

    • show dhcp lease
    • show ip interface brief, displaying interface IPv4 addresses
    • show running-config, displaying the configured DHCP pools
    • show ip route, displaying the installed IPv4 routes

  2. An administrator wants to set up a router as a DHCP server for the 10.10.10.0/24 subnet, but reserve addresses .1 through .10 for static assignment to servers and printers. Which command reserves that range before creating the pool?

    • ip dhcp excluded-address 10.10.10.1 10.10.10.10
    • host 10.10.10.10 255.255.255.0, under the DHCP pool
    • network 10.10.10.0 255.255.255.0, under the DHCP pool
    • ip helper-address 10.10.10.10 on the LAN interface

  3. Inside an ip dhcp pool configuration, which command tells clients in that pool what default gateway address to use?

    • default-router <ip>
    • dns-server <ip>, under the DHCP pool
    • ip default-gateway <ip>, in global configuration mode
    • next-server <ip>, under the DHCP pool

  4. DHCP clients and their server are on different subnets. Routing, the server scope, and ACLs are verified, but no relay is configured on the client-facing router interface. Which change allows initial client broadcasts to reach the server?

    • DHCP cannot work across routed subnets under any circumstances
    • Add ip helper-address to the client-facing interface to relay DHCP requests
    • The DHCP server needs a static route to the client subnet instead
    • The clients need to be manually configured with the server's IP address

  5. On a Cisco IOS DHCP server, which command shows which clients currently hold a leased IP address along with their hardware or client ID?

    • show ip dhcp binding
    • show dhcp lease
    • show ip dhcp pool
    • show mac address-table

  6. A Windows client that previously had a DHCP-assigned address is told to release its lease. Which command does this on the client, and what happens to its addressing afterward?

    • ipconfig /release releases the lease and removes the adapter's DHCP IPv4 settings
    • ipconfig /flushdns, which releases the DHCP lease as well as clearing cached names
    • ipconfig /renew, which discards the lease without requesting configuration
    • netsh dhcp release, which disables the network adapter entirely

  7. In an ip dhcp pool for IP phones, an engineer configures option 150 pointing to an IP address. What is this option used for?

    • It sets the DNS server address for the phones
    • It supplies the TFTP server address for phone configuration
    • It configures the default gateway for the phone subnet
    • It disables DHCP for that pool and forces static addressing

  8. An administrator wants to remove an existing DHCP pool named kibria and its exclusion range entirely from the router's configuration. Which pair of commands does this?

    • delete ip dhcp pool kibria, then delete ip dhcp excluded-address
    • no ip dhcp pool kibria, and no ip dhcp excluded-address <range>
    • shutdown ip dhcp pool kibria
    • clear ip dhcp pool kibria

  9. A router is configured with two separate DHCP pools, one for a PC subnet and one for a Voice VLAN subnet used by IP phones, each with a different default-router value. What determines which pool a given client's request is served from?

    • The first configured pool serves every request until it is exhausted, then the next pool is used
    • The receiving interface subnet, or relay subnet, selects the matching pool
    • The client's MAC address vendor prefix
    • DHCP pools always serve requests round robin regardless of subnet