Windows DHCP Split-Scopes in Address Manager - BlueCat Address Manager - 8.3.0

Address Manager Administration Guide

prodname
BlueCat Address Manager
version_custom
8.3.0

This topic explains importing a split-scope configuration from Managed Windows DHCP servers.

Address Manager can import a split-scope configuration from two Managed Windows DHCP servers. Windows DHCP split-scopes are usually configured in one of two ways:
  • The same DHCP scope exists on both servers; each server has an adjacent address pool.
  • The same DHCP scope exists on both servers with the same address pool defined; each server excludes the other server’s part of the address pool. This happens if you use the Split-Scope Wizard on Windows Server 2008 or greater.

Address Manager can import both types of configuration. In each case, the DHCP scopes on both servers must be identical. The other rules for importing split scopes are slightly different.

Example 1: Each server contains the same DHCP scope ( 192.168.1.0/24). The address pool is split into two parts, Server1 has one part (192.168.1.10 to 192.168.1.100) and Server2 has the other part (192.168.1.101 to 192.168.1.200).

After you import from the first DHCP server, the following data is added to Address Manager:
  • The IPv4 network that corresponds to the imported DHCP scope.
  • The DHCP range (including any exclusions or reservations).
  • A Master DHCP deployment role at the network level.
After you import data from the second DHCP server, the following changes are made on Address Manager:
  • The DHCP range expands to include the part from the second server.
  • A split address is added in the range, representing the IP address at which to divide it.
  • The second server is added as a secondary server to the existing DHCP deployment role.
    Note: The order of the servers from which you import data does not affect the result of the import.

To import this configuration as a split-scope, the address pools between the two servers must be contiguous. If there is a gap between the two pools, Address Manager does not import the pool from the second server.

Example 2: Each server contains the same DHCP scope ( 192.168.1.0/24). Each server also has the same address pool (192.168.1.10 to 192.168.1.200). Server1 excludes a part of the address pool (addresses.101 to.200) and Server2 excludes the complementary part of the address pool (addresses. 10 to.100).

After you import from the first DHCP server, the following data is added to Address Manager:
  • The IPv4 network that corresponds to the imported DHCP scope.
  • The DHCP range (all IP addresses being assigned by the other server are excluded from the range).
  • A Master DHCP deployment role at the network level.
After you import from the second DHCP server, the following changes are made on Address Manager:
  • The exclusion range is removed from the DHCP range.
  • A split address is added in the range, representing the IP address at which to divide it.

The second server is added as a secondary server to the existing DHCP deployment role.

When it imports this configuration, Address Manager examines the exclusion ranges within the address pools. If the largest exclusion ranges are adjacent to each other, the data is imported from the second server and the split-scope configuration is created. If the exclusion ranges are not adjacent to each other, Address Manager does not import data from the second server.