Foundation Summary

The Foundation Summary provides a convenient review of many key concepts in this chapter. If you are already comfortable with the topics in this chapter, this summary might help you recall a few details. If you just read this chapter, this review should help solidify some key facts. If you are doing your final prep before the exam, the following lists and tables are a convenient way to review the day before the exam.

A five-step process is used by DHCP to allocate IP addresses:

Clients broadcast with DISCOVER messages.
Servers respond with OFFER messages.

Clients REQUEST addresses.

Servers respond with ACKS to indicate the assignment is recorded.

Clients send ARP requests to see if their new addresses are in use.

There are three DHCP roles: server, relay, and client. The server is configured as follows:

Step 1.
Create a pool of addresses to assign to clients:

Router(config)# ip dhcp pool name

Step 2.
Assign a network to the pool:

Router(config-dhcp)# network network/mask

Step 3.
Specify the lease with default of one day:

Router(config-dhcp)# lease days

Step 4.
Identify the DNS server:

Router(config-dhcp)# dns-server address

Step 5.
Identify the default gateway:

Router(config-dhcp)#default-router ip-address

Use the following commands to configure DHCP relay:

  • ip helper-address address

  • forward-protocol udp port

An IOS device is configured as a DHCP client with the interface command ip address dhcp.

The show ip dhcp bindings command displays the active DHCP bindings.