2 DHCP Configuration and Troubleshooting Free Online FlashCards

What does a DHCP scope define?

A scope defines an IPv4 subnet and the range of addresses a DHCP server may lease on that subnet.

How should DHCP scopes be organized across client subnets?

Create a separate scope for each client subnet.

What do DHCP options 3, 6, and 15 provide?

Option 3 provides the default gateway, option 6 provides DNS servers, and option 15 provides the DNS domain name.

In a DHCP scope, what does the subnet ID identify?

The subnet ID identifies the scope; it is not an address assigned to a client.

Why exclude manually assigned infrastructure addresses from a DHCP pool?

Exclude manually assigned infrastructure addresses from dynamic allocation to prevent DHCP from leasing them to clients.

What is a DHCP lease, and how does its duration affect a network?

A lease is a time-limited address assignment. Shorter leases recycle addresses faster in high-turnover networks; longer leases reduce renewal traffic on stable networks.

What does a DHCP reservation do?

A reservation associates a specific address with a client identifier, commonly its network interface’s MAC address. The client still uses DHCP and normally receives that reserved address.

How should an administrator handle a device using a manual static address?

Keep a manually configured static address outside the dynamic pool or exclude it from the pool.

When is a DHCP relay agent needed, and what does it do?

A DHCP relay agent forwards DHCP requests from a client subnet to a server on another subnet, because routers normally do not forward local broadcasts.

How does a DHCP relay help a server choose the correct scope?

The relay supplies information identifying the client subnet, allowing the DHCP server to select the correct scope.

What is the typical order of messages in a DHCPv4 exchange?

DORA stands for Discover, Offer, Request, and Acknowledgment—the typical sequence of a DHCPv4 exchange.

What should you investigate if a client sends no DHCP Discover?

Check the client, network link, VLAN, and local broadcast path; a missing Discover suggests an issue at one of these points.