Configuring Exclusion Ranges

A DHCP exclusion range is a specified range of IP addresses residing within a DHCP range. An exclusion range is defined as a start/end IP address pair within an ipam/range object and is considered a sub-object within a regular DHCP range. IP addresses residing within the exclusion range are excluded from the pool of available IP addresses and are un-leasable. The DHCP server is prevented from assigning IP addresses within the exclusion range to network devices.

There can be multiple exclusion ranges within a DHCP range, but the exclusion range must be fully contained within a DHCP range. The exclusion range cannot overlap other exclusion ranges within the DHCP range. IP addresses within an exclusion range are excluded from being allocated as a DHCP lease unless a DHCP address already exists on the specific address. You can define an exclusion range, or multiple exclusion ranges, within a DHCP range. 

IP addresses residing within an exclusion range are labeled as DHCP Exclusion Range. An exclusion range can be created on already leased addresses, but the existing leases will not be renewed.

When an IP address is created that is both a member of an exclusion range and is a fixed address, the fixed address takes precedence over the range. By designating an IP address as a fixed address, the IP address is removed from the exclusion range. Similarly, when an exclusion range is created within a DHCP range, the exclusion range is removed from the DHCP range.

For information on creating address ranges, see Configuring Address Ranges.

To view the list of DHCP Exclusion ranges, complete the following:

1. From the Infoblox Portal, click Configure > Networking > IPAM/DHCP > Address Spaces.
2. Click IP Space > Address Block > Subnet > corresponding Range and click the respective range link.
3. From among the State options in the filters section, select Free to view all IP Addresses contained within the exclusion range. All IP addresses residing within an exclusion range will be labeled Exclusion Range.  
4. The information for each IP address in the exclusion range is displayed as follows:

• Address/Name: Displays start and end addresses of the address range.
• Description: Additional information about the address range.
• Usage: The usage of the address range (Fixed Address, DHCP Range, or Exclusion Range). An address within an exclusion range will have "Exclusion Range" as usage and will lose its DHCP Range usage. It is also possible that it will be combined with other usages such as Fixed Address, DHCP Range, and Exclusion Range, always in mutually exclusive scenarios.

You can click on an individual IP address within the exclusion range to view the details for the respective IP Address.

Valid and Invalid DHCP Exclusion Ranges

The following table describes a parent DHCP range of 192.168.1 0/24

You can also perform the following in this tab:

• Click the menu button, , to reorder the columns.

• Click the menu button, , then Edit or select the check box for the respective record and click the Edit button to modify an address range.

• Select an exclusion range to view additional details. You can view additional information like start and end addresses, IP space, tags, and DHCP options. If you do not want to view the details in the right panel, click the information button, .

• Click the utilization details button, , to view the address range utilization details or click the tabular view button, , to view the details in a tabular format.

• Enter the value that you want to search in the Search text box. The application displays the list of records matching the keyword in the text box.

• Click the filter button,   , to filter the objects by name and description. To save a filter after selecting the required parameters click Save Filter, specify a name for the filter, and click Save. To reload a previously saved filter, click the saved filters button, , and select the required filter. 

• Click the menu button, , Move to Recycle Bin to move the object to the recycle bin. You can restore the object later or delete it permanently as required. For more information, see Recycle Bin.

You can perform the following actions:

• Modifying Exclusion Ranges
• Creating Exclusion Ranges