Finding the first available IPv4 network in an IP block - BlueCat Address Manager - 9.2.0

Address Manager Administration Guide

BlueCat Address Manager

Search for the first free or unused IPv4 network within an IPv4 block.

A free or unused IP network is a network that doesn't yet exist, or that already exists but that doesn't have any assigned IP addresses (other than the network ID, gateway, and broadcast addresses).

An Address Manager configuration can have many IP blocks and each IP block can have many IP networks. You can use the Find Available IPv4 Networks function to quickly create or locate the first available IPv4 network. You can search through all blocks in your configuration, or you can search within a specific block.

The search displays only IPv4 networks to which you have at least view access rights. If Address Manager finds an unallocated network, you are directed to the network address page. If Address Manager cannot find an unallocated network, it tries to find a block that has sufficient free space to create the network of the desired size. In this case, only blocks to which you have access rights to add networks are considered. If there's no match, a message appears indicating that no free IPv4 network was found within the range.

When searching for the first available network within an IP block, you can only search for a network that's either the same size as or smaller than the block. For example, from the IPv4 block, you can only specify a network size value of /24 to /30. You can limit the search for a network by selecting the block in which to search.

To search all blocks for the available network:

  1. 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.
  2. From the configuration drop-down menu, select a configuration.
  3. Under IPv4 Blocks section, click Action and select Find Available IPv4 Network.
  4. Under Search Option, set the search parameters:
    • Size of the range—select a network size. Network sizes in the drop-down menu will be populated based on the selected block or configuration, and will be listed by CIDR notation and by the number of addresses within the network.
    • Number of networks to find—specify number of networks to be found or created.
    • Reuse existing unused ranges—select this option to find the existing unused networks of similar size. By default, this option isn't selected and Address Manager always creates a new network of specified size.
    • Find first available network with exactly equal size—select this option to locate a network that's of the size selected in the Size of the range drop-down list.
    • Find first available network with equal or larger size—select this option to locate a network equal to or larger than the size selected in the Size of the range drop-down list.
  5. Click Yes.
    • If Address Manager can't find a network, a message appears at the top of the page to indicate that no network was found or created. Modify your search criteria to perform another search.
    • If Address Manager finds an existing network matching the specified search criteria, the Addresses tab for the network appears.
    • If the Reuse existing unused ranges option isn't selected and Address Manager finds a sufficient network space matching the specified search criteria that can be created, the Add IPv4 Network Confirmation page opens.
  6. Under General, review the ranges found and set the following options:
    • Name—specify a name for the network to be created.
    • Add Default Gateway—select this option to set the network gateway as the second address in the network. By default, this option is selected.
    • Custom Gateway—select this option and type an IP address in the field to specify a custom location for the network gateway.
    • Select Template—select a network template from the drop-down menu if you want to apply standard settings to an IPv4 network, such as the gateway address, reserved addresses, DHCP ranges, or IP group. This option becomes available when there's at least one network template created.
    • Default View—select a view from the list. The selected view is inherited by addresses within in the network. For IP addresses that are assigned to multiple views, the default view determines the view to which the IP address is assigned.
    • Location—(Optional) select a location from the drop-down menu on which the IP object that you are adding or editing will be based. The most frequently used location objects are at the top of the list.
      • Inherited Location—displays the location annotation that's inherited from the parent object. If you don't include a location, this default location will be used for the current object and its child objects.

    For complete instructions on creating the new network, refer to Working with IPv4 networks.

    Note: You can restrict your search for the first available IPv4 network to a specific IPv4 block. Navigate to the IPv4 block that you want to search. On the block’s Address Space tab, click Action and then select Find Available IPv4 Networks.