Shared networks - BlueCat Address Manager - 9.2.0

Address Manager Administration Guide

BlueCat Address Manager

Shared network declarations in DHCP are used to group together different logical subnets that share the same physical network.

For example, consider a network with 250 workstations on a physical network with the logical address ID of You need to add 100 workstations to this physical network, but the only available subnet ID is If the subnets were contiguous (that is, and, you could modify the subnet mask to create a single logical subnet to accommodate the additional computers ( However, the two network IDs aren't contiguous.

By configuring a shared network, you can group the two networks together. The benefit is that your DHCP server can allocate IP addresses from the common shared network to any host on either of the networks, without the need to isolate the networks to different router interfaces.

Tag groups and tags are the mechanism by which subnets are grouped into DHCP shared networks. To use shared networks, you must create a tag group and a tag, then you need to associate a single tag group with a configuration. A configuration can have many associated tags, but only one tag that's associated for the purpose of forming shared networks.

Use the Associate Shared Network Tag Group link on the configuration Details tab to associate a tag group and its tags to a configuration to create a shared network.

Note: For shared networks, each member network of the shared network must have the same type of DHCP deployment role assigned to its network object.
Note: Customers with multiple DHCP ranges configured with multiple IP service addresses will need to create Shared Networks to deploy DHCP service properly. For more information, refer to DHCP with multiple IP service addresses.