CCNA 2 v7.0 Curriculum: Module 7 - DHCPv4

7.0 Introduction

7.0.1 Why should I take this module?

• DHCPv4 Overview: Assigns IP addresses dynamically in an IPv4 network, reducing manual configuration.
• Benefits: Simplifies IP address management, especially in large networks.
• Learning Focus: Configure Cisco IOS router as a DHCPv4 server and client.

7.0.2 Learning Objectives

• DHCPv4 Concepts: Understand DHCPv4 operations in business networks.
• Configure a Cisco IOS DHCPv4 Server: Set up a router as a DHCPv4 server.
• Configure a DHCPv4 Client: Set up a router as a DHCPv4 client.

7.1 DHCPv4 Concepts

7.1.1 DHCPv4 Server and Client

• Function: Dynamically assigns IPv4 addresses and network info to clients.
• Configuration Options: Cisco routers can provide DHCPv4 services in small/remote setups.
• Lease: Temporary IP address assignment, typically ranging from 24 hours to a week.

7.1.2 DHCPv4 Operation

• Client/Server Mode: Clients lease IP addresses from the server until the lease expires.
• Lease Renewal: Clients must periodically extend leases to retain IP addresses.

7.1.3 Steps to Obtain a Lease

1. DHCP Discover (DHCPDISCOVER)
2. DHCP Offer (DHCPOFFER)
3. DHCP Request (DHCPREQUEST)
4. DHCP Acknowledgment (DHCPACK)

7.1.4 Steps to Renew a Lease

• DHCP Request (DHCPREQUEST): Sent to original DHCP server for lease renewal.
• DHCP Acknowledgment (DHCPACK): Server confirms lease renewal.

7.2 Configure a Cisco IOS DHCPv4 Server

7.2.1 Cisco IOS DHCPv4 Server

• Purpose: Enables a router to assign/manage IP addresses.

7.2.2 Steps to Configure a Cisco IOS DHCPv4 Server

Step 1: Exclude IPv4 Addresses

• Command: ip dhcp excluded-address low-address [high-address]

Step 2: Define a DHCPv4 Pool Name

• Command: ip dhcp pool pool-name

Step 3: Configure the DHCPv4 Pool

• Tasks include defining:
  • Address pool
  • Default gateway
  • DNS and domain name
  • Lease duration

7.2.3 Configuration Example

• Example: Configuration commands to set up a DHCPv4 server.

7.2.4 DHCPv4 Verification Commands

• Commands: show running-config | section dhcp, show ip dhcp binding, show ip dhcp server statistics

7.2.5 Verify DHCPv4 is Operational

• Verification: Using commands to check IP assignment.

7.2.6 Syntax Checker Activity

• Activity: Configure DHCPv4 server for a specific network.

7.2.7 Disable the Cisco IOS DHCPv4 Server

• Command: no service dhcp to disable, service dhcp to re-enable.

7.2.8 DHCPv4 Relay

• Purpose: Forward DHCP requests across different networks.

7.2.9 Other Service Broadcasts Relayed

• Ports Forwarded by ip helper-address: Time, TACACS, DNS, DHCP/BOOTP, TFTP, NetBIOS services.

7.2.10 Packet Tracer Activity

• Objectives: Configure DHCP server, relay, and client.

7.3 Configure a DHCPv4 Client

7.3.1 Cisco Router as a DHCPv4 Client

• Scenario: Configuring a router to receive IP via DHCP from ISP.

7.3.2 Configuration Example

• Command: ip address dhcp to set interface as DHCP client.

7.3.3 Home Router as a DHCPv4 Client

• Default Setting: Home routers typically set to automatic DHCP configuration.

7.3.4 Syntax Checker Activity

• Activity: Configure a router to be a DHCP client.

7.4 Module Practice and Quiz

7.4.1 Packet Tracer Implement DHCPv4

• Tasks: Configure DHCP server, client, and relay.

7.4.2 Lab Implement DHCPv4

• Objectives: Build network, configure DHCP servers, and relay.

7.4.3 Summary

• DHCPv4 Concepts: Understanding DHCPv4 operations and configurations.
• Server Configuration: Setting up and verifying DHCPv4 servers.
• Client Configuration: Setting up routers as DHCP clients.

7.4.4 Module Quiz

• Assessment: Evaluate understanding of DHCPv4 configurations and concepts.