Finding the first available IPv4 network in an IP block - BlueCat Integrity - 26.1.0

Address Manager Administration Guide
ft:locale
en-US
Product name
BlueCat Integrity
Version
26.1.0

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 10.0.0.0/24 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 IPAM tab in the sidebar, then select IPv4 blocks.
  2. Navigate to the IPv4 block that you would like to find a network within by selecting the block's range in the IPv4 blocks table, or by selecting the block in the IPAM tree view panel.
  3. Select Actions > Find first available IPv4 network.
  4. Under Networks, set the search parameters:
    • Size of the range—select a range size. Range sizes in the drop-down menu will be populated based on the selected block, and will be listed by CIDR notation and by the number of addresses within the range.
    • Reuse existing unused ranges—select this option to find the existing unused ranges of similar size. By default, this option isn't selected and Address Manager always creates a new range of specified size.
    • Method to find first available range—set the following parameters:
      • Find block with exact size—select this option to locate a network that's of the size selected in the Size of the range drop-down list.
      • Find block 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. Select Find networks.

    • If Address Manager can't find a network, an error message will appear to indicate that no suitable network was found. Modify your search criteria to perform another search.

    • If a network matching the specified search criteria can be created, the block will appear at the top in the The First available network field.

  6. On the General tab, configure the following parameters:
    • Name—enter a name for the network. This name is used only in Address Manager and isn't deployed to servers.
    • Location—select a location from the drop-down menu on which the IP object that you are adding or editing will be based. Networks will inherit the location of the parent block, unless a different location is specified at the network level here.
    • 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.
    • Under Gateway definition, select a method to define the network gateway.
      • Default—select this option to set the network gateway as the second address in the network.
      • None—select this option to create a network with no default gateway.
      • Custom—select this option and type an IP address in the field to specify a custom location for the network gateway.
    • Dynamic update of DHCP reservations—select this check box to enable the dynamic update of DHCP reserved IPv4 addresses. Refer to Dynamic Update of DHCPv4 reserved addresses for more information.
  7. On the DNS restrictions tab, set the zones or views to restrict the IPv4 network to be used in:
    • Inherit restricted domains from parent—select the checkbox to inherit the parent object’s DNS restrictions. Selecting this option will autopopulate the Inherited restricted domains field with the names of restricted DNS zones and views defined in the parent object.

      Unselect the checkbox to display the Restricted domains field. In the Restricted domains field, enter the names of DNS zones and views to configure network-specific restricted domains settings.

    • Note:
      • Any DNS zone or view you add to the Restricted domains list is restricted for use only in the specified IPv4 network. The IPv4 network is also restricted for use only in the specified view(s) and zone(s).
      • You can't add an IPv4 network to a DNS zone if that DNS zone contains IP addresses outside of that IPv4 network.
  8. On the Default domains tab, set the zones—containing domains—to be used when you are configuring the host name for an IPv4 address. The default domains help ensure accuracy when specifying the host name for an IPv4 address. When this is configured, you don't have to type the complete FQDN(s); you can select the name from a list of available domains.
    • Inherit default domains from parent—select the checkbox to inherit the parent object’s default domains. Selecting this option will autopopulate the Inherited default domains field with the names of DNS zones defined in the parent object.

      Unselect the checkbox to display the Default domains field. In the Default domains field, enter the names of DNS zones to configure network-specific default domains settings.

    • Note: If you set DNS restrictions in the DNS restrictions section, the default view and default domains must be located in the view and zone restrictions.

      The zones specified here will be available in the Host record field, when you are assigning an IPv4 address.

  9. On the Assignment options tab, set the following options:
    • Duplicate name check—select Enable to prevent the use of duplicate host names in the network, or select Disable to allow the use of duplicate host names. Select Inherited to have the network inherit the duplicate name check setting of its parent object.
    • Ping before assignment—select Enable to have Address Manager ping IP addresses before assigning them, or select Disable to have Address Manager assign addresses without checking their availability. When Address Manager pings an address and finds that it's in use, Address Manager indicates that the address is in use and can't be assigned. Select Inherited to have the network inherit the ping before assign setting of its parent object.
  10. On the DHCP alert settings tab, set the values for DHCP alerts:
    • Inherit watermark value from parent—when selected, the network inherits the DHCP alert settings from its parent object.

    • Low watermark (%)—triggers an alert when DHCP use falls below this value (when too few addresses are being used).

    • High watermark (%)—triggers an alert when a DHCP use rises above this value (when too many addresses are being used).

    Note: If you are using a shared network in DHCP, a DHCP alert notification for all networks inside the shared network will be sent as a single entity notification using the DHCP alert set at the configuration level. DHCP alerts for each individual network within any shared network will also be sent only if object-specific DHCP alerts are set at the network or DHCPv4 range level.
  11. In the Change control section, add comments if required.
  12. Select Create or Create and add another.