Resizing DHCPv4 ranges - BlueCat Address Manager - 8.3.1

Address Manager Administration Guide

prodname
BlueCat Address Manager
version_custom
8.3.1

Resize DHCPv4 ranges to make them larger or smaller.

When you resize a range, you can select how Address Manager handles DHCPv4 addresses that no longer fit in the range, and you can create split-scope networks for ranges on Windows servers.

To resize a DHCPv4 range:

  1. From the configuration drop-down menu, select a configuration.
  2. Select the IP Space tab. Tabs remember the page you last worked on, so select the tab again to ensure you're on the Configuration information page.
  3. Under IPv4 Blocks, click an IPv4 block.
  4. Under Blocks and Networks, click an IPv4 network.
  5. Click the DHCP Ranges tab.
  6. Under DHCP Ranges, click the DHCP range you want to resize.
  7. Click the DHCP range name menu and select Resize.
  8. From the Create By drop-down menu under Address Range, select the type of method that will be used to create a DHCP range and define the address range. Parameter fields for the option vary by a type of method that you select.
    • If you select IP Addresses, the following fields will be populated:
      • Start—type the address for the start of the DHCP range.
      • End—type the address for the end of the DHCP range.
      • Name—type a descriptive name for the DHCP range.
      • Split DHCP range around static and reserved addresses—select this check box to automatically split the DHCP range at any static or reserved addresses that may be in the network and within the DHCP range. Upon deployment, Address Manager automatically creates multiple DHCP pools on the managed server, leaving any static addresses outside of the DHCP range you specify. When not selected, any static or reserved addresses within the DHCP range become part of the DHCP range.
    • If you select Offsets, the following fields will be populated:
      • Start Offset—enter a value for the starting position of the DHCP range. Start Offset will be counted from the very first IP address which is Network ID.
      • End Offset—enter a value for the ending position of the DHCP range. End Offset will be counted from the very last IP address which is Network Broadcast Address.
      • Name—type a descriptive name for the DHCP range.
      • Split DHCP range around static and reserved addresses—select this check box to automatically split the DHCP range at any static or reserved addresses that may be in the network and within the DHCP range. Upon deployment, Address Manager automatically creates multiple DHCP pools on the managed server, leaving any static addresses outside of the DHCP range you specify. When not selected, any static or reserved addresses within the DHCP range become part of the DHCP range.
    • If you select Offset and Percentage, the following fields will be populated:
      • Offset—enter a value for the starting position of the DHCP range. The position of Offset will be counted from the very first IP address or the last IP address in the network depending on the direction option that you select in the Direction field. Offset must not be zero.
      • Percentage—enter a value for the size of the DHCP range in proportion to the parent network size. For example, the value 20 represents 20% of the parent network size. Percentage must not be zero and be equal to or less than 100%.
      • Direction—select the starting IP address’ offset position. If you select from start, the position of the starting IP address will be counted from the very first IP address in the network. If you select from end, the position of the starting IP address will be counted from the very last IP address in the network.
      • Name—type a descriptive name for the DHCP range.
      • Split DHCP range around static and reserved addresses—select this checkbox to automatically split the DHCP range at any static or reserved addresses that may be in the network and within the DHCP range. Upon deployment, Address Manager automatically creates multiple DHCP pools on the managed server, leaving any static addresses outside of the DHCP range you specify. When not selected, any static or reserved addresses within the DHCP range become part of the DHCP range.
  9. Under DHCP Exclusions Range, enter the start address and the end address of the range that you wish to exclude in the Start IP and End IP fields, then click Add. To exclude a single address, enter the same address in the Start IP and End IP fields.
  10. Under Pool Resize Options, select an option to determine how Address Manager handles any DHCP allocated addresses that are no longer part of the resized range. When you reduce the size of a DHCP range, it is possible for DHCP allocated addresses to be orphaned or left out of the smaller range. You can convert orphaned addresses to DHCP Reserved, Static, or Unassigned addresses.
    • DHCP Reserved hosts—when selected, Address Manager converts orphaned addresses to DHCP Reserved addresses.
    • Static hosts—when selected, Address Manager converts orphaned addresses to Static addresses.
    • Unassigned hosts—when selected, Address Manager converts orphaned addresses to Unassigned addresses.
  11. Under Scope (Range) Split, select the Scope Split Windows Network checkbox to create a split scope range. It creates a split scope range for two Windows servers. Define the split scope parameters in the fields that appear:
    • Exclude Server 1—when selected, the entire range is excluded from the first server. The entire range will be hosted on the second server.
    • Exclude Server 2—when selected, the entire range is excluded from the second server. The entire range will be hosted on the first server.
    • Split Address—select this option and type the IP address at which the scope is to be split; the range will be split between the two servers at the split address. The first portion of the range, from the start address to the split address, will be active on Server 1 and excluded from Server 2. The second portion of the range, from the first address after the split address to the end address, will be active on Server 2 and excluded from Server 1. For more information when used with Windows servers, refer to BlueCat Address Manager for Windows Server.
    • Preview button—click to display a preview of how the split scope DHCP range will be deployed. The Server 1 and Server 2 fields show the address ranges to be deployed to each server.
  12. Under Change Control, add comments, if required.
  13. Click Update.