ip dhcp excluded-address [start] [end]
Excludes one or more IP addresses from the DHCP pool so they are not automatically assigned to clients, typically used for static assignments like servers or routers.
ip dhcp excluded-address [start] [end]When to Use This Command
- Reserving a range of IPs for static devices such as printers or servers within a DHCP scope.
- Excluding the default gateway address (e.g., router interface) from being leased to clients.
- Preventing DHCP from assigning addresses already used by network infrastructure devices.
- Creating a small exclusion range for future static assignments without modifying the pool size.
Command Examples
Exclude a single address
ip dhcp excluded-address 192.168.1.1No output is generated upon successful configuration. The command simply excludes 192.168.1.1 from being leased.
Exclude a range of addresses
ip dhcp excluded-address 192.168.1.1 192.168.1.10No output is generated. The range 192.168.1.1 through 192.168.1.10 is excluded from DHCP assignment.
Understanding the Output
This command does not produce any output on successful execution. To verify excluded addresses, use 'show ip dhcp pool [pool-name]' or 'show ip dhcp binding'. The excluded addresses are listed under the pool's configuration. If an excluded address appears in the binding table, it indicates a misconfiguration or that the address was manually assigned via static binding.
CCNA Exam Tips
Remember that excluded addresses must be configured before creating the DHCP pool; otherwise, the pool may already have assigned those addresses.
The 'ip dhcp excluded-address' command is applied globally, not under the DHCP pool configuration mode.
You can exclude a single address by omitting the end parameter, or a range by specifying both start and end.
CCNA exam may test that excluded addresses are not shown in 'show ip dhcp binding' output.
Common Mistakes
Forgetting to exclude the router's interface IP address, causing duplicate IP conflicts.
Excluding addresses after the DHCP pool has already leased them, requiring manual release or renewal.
Using the command under DHCP pool configuration mode instead of global configuration mode.
Related Commands
ip dhcp pool [name]
Creates a DHCP pool and enters DHCP pool configuration mode, where you define the subnet, default gateway, DNS servers, and other DHCP options for assigning IP addresses to clients.
show ip dhcp binding
Displays the current DHCP binding table, showing which IP addresses have been leased to clients, along with their MAC addresses, lease expiration, and type of binding.
show ip dhcp pool
Displays the configuration and utilization statistics of a DHCP pool, used to verify pool settings and address allocation status.
Practice for the CCNA 200-301
Test your knowledge with hundreds of CCNA practice questions covering all exam domains.
Practice CCNA Questions