Cisco Certified Network Associate (CCNA) Practice Exam

What configuration command is used to exclude specific IP addresses from a DHCP pool?

1. ip dhcp excluded-address

2. set excluded addresses

3. exclude ip address

4. dhcp exclude

The correct answer is: ip dhcp excluded-address

The command used to exclude specific IP addresses from a DHCP pool is "ip dhcp excluded-address." This command is essential in DHCP configuration because it allows network administrators to reserve certain IP addresses, preventing the DHCP server from assigning them to clients. For instance, if there are static IP address assignments for printers, servers, or other network devices, these addresses need to be excluded from the DHCP pool to ensure that the DHCP server does not inadvertently assign them to other devices, which could lead to IP address conflicts. The syntax requires the administrator to define the range of IP addresses to be excluded, ensuring that dynamic assignments do not interfere with designated static IP addresses. This command is a foundational aspect of maintaining a stable network environment when using DHCP. In contrast, the other options provided do not correspond to the actual command syntax used in Cisco devices for this specific function, making them incorrect. This understanding is crucial for effectively managing IP address allocation in a network.