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Managing IPv4 Networks

Owned by Aliaksei Shautsou (Deactivated)
Last updated: Apr 06, 2018 by Youlia Ushakova (Deactivated)
17 min read

In Grid Manager, you use the Net Map (network map) and List panels to manage your IPv4 network infrastructure. After you select a network container from the IPAM tab, Grid Manager displays it in the Net Map panel, by default. The Net Map panel provides a graphical view of your networks and has a number of features that simplify network management. The List panel displays the networks in table format.
You can always switch your view of a network container between the Net Map and List panels. Grid Manager keeps track of which panel you last used. When you select a network container, Grid Manager displays it in the Net Map or List panel, depending on which one you last used. For information about each panel, see IPv4 Network Map and IPAM Home.
Use the IP Map and List panels to manage the IP addresses in leaf networks. For information, see Viewing and Managing IPv4 Addresses.
After you create an IPv4 network, you can modify its properties, resize it, use the split network feature to create subnets, enable discovery to discover routers, switches, firewalls, wireless access points and other device types within it, or join it to another network to create a larger network that encompasses adjacent subnets. You can do the following from both the Net Map and List panels:

    IPv4 Network  Map

After you select an IPv4 network container from the IPAM tab, Grid Manager displays it in the Net Map (network map) panel, by default. Net Map provides a high-level view of your IPv4 network address space. You can use Net Map to design and plan your network infrastructure, configure and manage individual networks, and evaluate their utilization. Its unique display of the IPv4 network address space across multiple rows is similar to a road map that starts with the first IP address in the network and ends with the last address. Net Map displays the network address space across a maximum of eight rows, depending on the size of the network. It automatically scales the map so that it displays the entire address space of a network container.
The Net Map panel presents a complete view of the network space, including the different types of networks that are in it and its unused address space. IP addresses that belong to a network are blocked off. Each color-coded block represents a network container, a leaf network, or a block of networks that are too small to be displayed individually in the map. For example, in a /8 or /16 network, networks smaller than /20 or /28 respectively and that are beside each other are represented as a multiple network block. In addition, the fill pattern of the blocks indicates their utilization. Therefore, you can quickly evaluate how many and what type of networks are in a network container, their relative sizes, utilization, and how much space you have left.
As you mouse over areas of the map, it displays IP information about the area. Net Map also has a zoom feature that allows you to enlarge or reduce your view of a particular area.
Figure 13.6 displays the network map of a 20.0.0.0/8 network, which is a network container that has network containers and leaf networks. 

 Figure 13.6 20.0.0.0/8 Network Map


Displaying IP Information 
As shown in Figure 13.6, as you mouse over the map, Net Map displays IP information about the area. When you mouse over an unused area, Net Map displays the following information:

  • The start and end IP address
  • The number of IP addresses that can fit in that space
  • The largest possible network
  • The number of /16 and /24 networks that can fit in that space

When you mouse over a network, Net Map displays the following information:

  • Network address and netmask
  • Utilization of the network. For a leaf network, Net Map reports the percentage of used IP addresses, except the broadcast and network addresses. For a network container, Net Map reports the percentage of the IP address space that has been allocated to either network containers or leaf networks.
  • The first and last IP address of the network
  • The total number of IP addresses in the network

When you mouse over a block of multiple networks, Net Map displays the following information:

  • The start and end IP address of that block of networks
  • The total number of IP addresses in that block of networks
  • The number of networks in that block

Zooming In and Out

Use the zoom function to enlarge and reduce your view of a selected area. You can zoom in on any area in your network. You can zoom in on an area until it displays 128 addresses per row, for a total of 1024 addresses for the map. When you reach the last possible zoom level, the Zoom In icon in the Net Map task bar and the menu item are disabled.
After you zoom in on an area, you can click the Zoom Controller icon to track where you zoomed in. The Zoom Controller lists all the areas that you zoomed in and updates its list dynamically. You can click an item on the list to view that area again. Click the Zoom Controller again to close it.
To select an area and zoom in:

  1. Right-click and select Zoom In, or click the Zoom In icon in the Net Map task bar. The pointer changes to the zoom in selector.
  2. Select a starting point and drag to the end point. The starting point can be anywhere in the map. It does not have to be at the beginning of a network.
    Net Map displays a magnified view of the selected area after you release the mouse button. As you mouse over the zoomed in area, Net Map displays IP information about it.
  3. You can do the following:
    • Select an area and zoom in again.
    • Add a network. If you zoom in on an area and click Add without selecting an open area first, Net Map selects the area where it can create the biggest possible network in that magnified area.
    • Select a network and perform any of the following operations:
      • Split the network.
      • Join it to another network.
      • Resize the network.
      • Edit its properties.
      • Open it to display its network or IP map.
    • Right-click and select Zoom Out, or click the Zoom Out icon in the Net Map task bar. Each time you click Zoom Out, Net Map zooms out one level and the Zoom Controller is updated accordingly.

Net Map Tasks

From Net Map, you can create IPv4 networks, and evaluate and manage your network resources according to the needs of your organization. You can do the following:

Adding a Network from Net  Map

When you create networks from Net Map, you can evaluate your network infrastructure and add networks accordingly. You can view the address space to which you are adding a network, so you can determine how much space is available and which IP addresses are not in use. When you mouse over an open area, Net Map displays useful information, such as the largest possible network that fits in that area and the total number of IP addresses. In addition, you can create networks without having to calculate anything. When you add a network, Net Map displays a netmask slider so you can determine the appropriate netmask for the size of the network that you need. As you move the slider, it displays network information, including the total number of addresses. After you select the netmask, you can even move the new network around the open area to select another valid start address.
To add a network from the Net Map panel:

  1. Do one of the following:
    • Click the Add icon.
      Net Map displays the netmask slider and outlines the open area that can accommodate the largest network.
    • Select an open area, and then click the Add icon.
      Net Map displays the netmask slider and outlines the largest network that you can create in the open area that you selected.
  2. Move the slider to the desired netmask. You can move the slider to the netmask of the largest network that can be created in the open area.
    As you move the slider, Net Map displays the netmask and its corresponding number of IP addresses. The outline in the network map also adjusts as you move the slider. When you mouse over the outline, it displays the start and end address of the network.
  3. After you set the slider to the desired netmask, you can drag the new network block around the open area to select a new valid starting address. You cannot move the block to a starting address that is invalid.
  4. Click Launch Wizard to create the network.
    The Add Network wizard displays the selected network address and netmask.
  5. You can add comments, automatically create reverse mapping zones, and edit the extensible attributes. (For information, see Adding IPv4 Networks.) You cannot change the network address and netmask.
  6. Save the configuration and click Restart if it appears at the top of the screen. Grid Manager updates Net Map with the newly created network.

Viewing Network Details

From the Net Map panel, you can focus on a specific network or area and view additional information about it. If you have a network hierarchy of networks within network containers, you can drill down to individual leaf networks and view their IP address usage.

  1. Select a network or area.
  2. Click the Open icon.
    • If you selected a network container, Grid Manager displays it in the Net Map panel. You can drill down further by selecting a network or open area and clicking the Open icon again.
    • If you selected a block of multiple networks, Grid Manager displays the individual networks in the Net Map panel. You can then select a network or open area for viewing.
    • If you selected a leaf network, Grid Manager displays it in the IP Map panel.
    • If you selected an open area, Grid Manager displays an enlarged view of that area in the Net Map panel.

This is useful when you are creating small networks in an open area.

    IPAM  Home

The IPAM Home panel is an alternative view of an IPv4 and IPv6 network hierarchy. For a given network, the panel shows all the networks of a selected network view in table format. This panel displays only the first-level subnets. It does not show further descendant or child subnets. You can open a subnet to view its child subnets. Subnets that contain child subnets are displayed as network containers. If the number of subnets in a network exceeds the maximum page size of the table, the network list displays the subnets on multiple pages. You can use the page navigation buttons at the bottom of the table to navigate through the pages of subnets.
The IPAM home panel displays the following:

  • Network: The network address.
  • Comment: The information you entered about the network.
  • RIR Organization: This appears only if support for RIR updates is enabled. This displays the name of the RIR organization to which the network is assigned.
  • RIR OrganizationID: This appears only if support for RIR updates is enabled. This displays the ID of the RIR organization to which the network is assigned.
  • RIR RegistrationStatus: This appears only if support for RIR update is enabled. This field displays the RIR registration status. This can be Registered or Not Registered. Registered indicates that the network has a corresponding entry in the RIPE database.
  • Last Registration Updated: Displays the timestamp when the last registration was updated. The displayed timestamp reflects the timestamp used on the Grid Master.
  • Status of Last Registration Update: Displays the registration status and communication method of the last registration update. The status can be Pending, Sent, Succeeded, or Failed. Each time you send a registration update to create, modify, or delete a network container or network, the updated status will be displayed here. If you have selected not to send registration updates, the previous status is retained.
  • IPAM Utilization: For a network, this is the percentage based on the IP addresses in use divided by the total addresses in the network. For example, in a /24 network, if there are 25 static IP addresses defined and a DHCP range that includes 100 addresses, the total number of IP addresses in use is 125. Of the possible 256 addresses in the network, the IPAM utilization is about 50% for this network.
    For a network container that contains subnets, this is the percentage of the total address space defined within the container regardless of whether any of the IP addresses in the subnets are in use. For example, when you define a /16 network and then 64 /24 networks underneath it, the /16 network container is considered 25% utilized even when none of the IP addresses in the /24 networks is in use.
    You can use this information to verify if there is a sufficient number of available addresses in a network. The appliance updates the IPAM utilization data immediately for a network container, but for a network it is updated every 15 minutes.
    The IPAM utilization data is displayed in one of the following colors:
  • Red: The IPAM utilization percentage is above the configured Trigger value.
  • Blue: The IPAM utilization percentage is below the configured Trigger value.
  • Active Users: The number of active users on the selected network.
  • Discovery Engine: Displays the discovery engine that performs the discovery process. This can be Network Insight, NetMRI, or vDiscovery. This field displays None if you have added or imported the network container or network manually.
  • Site: The site to which the IP address belongs. This is a predefined extensible attribute. 

  • Bridge Domain: The name of the discovered bridge domain. This column will display values only for IP addresses that are discovered from Cisco APIC by Network Insight or NetMRI. If discovered by NetMRI, the value will be populated through IPAM Sync. Otherwise, this column will be blank. For information about how to configure Cisco APIC, see Configuring Cisco Application Policy Infrastructure Controller (APIC).     

  • Tenant: The name of the discovered tenant. This column will display values only for IP addresses that are discovered from Cisco APIC by Network Insight or NetMRI. If discovered by NetMRI, the value will be populated through IPAM Sync. Otherwise, this column will be blank. For information about how to configure Cisco APIC, see Configuring Cisco Application Policy Infrastructure Controller (APIC).

You can select the following columns for display:

  • Disabled: Indicates whether the network is disabled.
  • Leaf Network: Indicates whether the network is a leaf network or not. A leaf network is a network that does not contain other networks.
  • Discovery Enabled: (Applies only with Network Insight) Indicates whether discovery is allowed on the network container or the network.
  • Discover Now: (Applies only with Network Insight) Indicates when the network is undergoing a current discovery process. A "Pending" icon appears in this column when you start the discovery and displays Completed after the completion of the discovery process.
  • VLAN ID: (AppliesonlywithNetworkInsight) The VLAN ID on the switch port.
  • VLAN Name: (AppliesonlywithNetworkInsight) The VLAN name on the switch port.
  • Managed: (AppliesonlywithNetworkInsight) Indicates whether the network is set to Managed status under Grid Manager. For more information, see the section Converting Unmanaged Networks under IPAM to Managed Status.
  • First Discovered: (AppliesonlywithNetworkInsight) The date and timestamp of the first occasion that Grid Manager discovered the network.
  • Last Discovered: (AppliesonlywithNetworkInsight) The date and timestamp of the last occasion that Grid Manager performed discovery on the network. The timestamp is updated whenever any new IP from this network is discovered.
  • Extensible attributes and RIR attributes: You can select the extensible attributes such as Building, Country, Region, State, and VLAN for display. When you enable support for RIR registration updates, you can also select associated RIR attributes for display. For information about RIR attributes, see Managing RIR Attributes.
  • Active Directory Sites: You can also select Active Directory Sites for display. For information about Active Directory Sites, see About Active Directory Sites and Services.

You can sort the list of networks in ascending or descending order by columns. For information about customizing tables in Grid Manager, see Customizing Tables.
You can also modify some of the data in the table. Double click a row of data, and either edit the data in the field or select an item from a drop-down list. Note that some fields are read-only. For more information about this feature, see Modifying Data inTables.

Tip: If you select a network from the list and switch to the Net Map panel, the network is also selected in the network map.

Filtering the Network List

You can filter the network list, so it displays only the networks you need. You can filter the list based on certain parameters, such as network addresses, comments and extensible attributes. When you expand the list of available fields you can use for the filter, note that the extensible attributes are those with a gray background.

    Resizing IPv4 Networks

You can resize a network to incre ase or decrease the network size and the number of IP addresses in the network. When you resize a network to a smaller netmask, you increase the number of IP addresses within that network. You can change the size of an IPv4 network when the operation does not affect existing objects in the network. You can resize an existing network only if the resized network does not exceed the upper network limit or create orphan objects, such as hosts and DHCP ranges. When a network has a parent network or subnets, the upper limit of the network size is marked in red in the resize network slider, and you cannot resize beyond this limit. For example, if a network has a /16 parent network, you cannot resize the network to a network that is larger than /16.
Before you resize an RIR allocated network block, ensure that the network block has already been registered at the corresponding RIR. Otherwise, when you reassign addresses within this block, the registration updates may fail. For information about RIR registration updates, see RIR Registration Updates.
To resize a network:

  1. From the Net Map or List panel, select a network, and then click Resize from the Toolbar.
  2. In the Resize Network editor, do the following:
    • Address: Displays the network address. You cannot modify this field.
    • Netmask: Displays the netmask of the network as you resize the network. You cannot modify this field.
    • Resize slider: Use the resize network slider to specify the appropriate subnet masks for the subnets. When you move the slider, Grid Manager displays the number of subnets and IP addresses within that subnet.
    • Automatically create reverse-mapping zone: This is enabled only when you resize a /8, /16, or /24 network. Select this check box to have the appliance automatically create reverse-mapping zones for the subnet. The appliance automatically creates reverse-mapping zones only for /8, /16, and /24 netmasks.
  3. Click OK.

    Splitting IPv4 Networks into  Subnets

You can create smaller subnets simultaneously within a network by splitting it. You do not have to configure each subnet individually. You can create smaller subnets with larger netmasks. A larger netmask defines more networks with a smaller number of IP addresses.
These subnets inherit the address properties of the parent network, such as member assignments. The exceptions are the default router and broadcast address configuration. The default router and broadcast address configuration for address ranges and fixed address are disabled by default after splitting a network. You can enable these properties for each subnet after splitting the parent network.
Note that you cannot split a network that is part of a shared network. To split a network:

  1. From the Net Map or List panel, select the check box of a network, and then click Split from the Toolbar.
  2. In the Split Network editor, do the following:
    • Address: Displays the network address. You cannot modify this field.
    • Netmask: Displays the netmask of the network. You cannot modify this field.
    • Subnetworks: Displays the number of subnets and IP addresses for each subnet.
    • Split network slider: Use the split network slider to specify the appropriate subnet masks for each subnet. When you move the slider, Grid Manager displays the number of subnets and the IP address range within that subnet.
    • Immediately Add: Select one of the following options.
      • Only networks with ranges and fixed addresses and unmanaged: Adds only the networks that have DHCP ranges, fixed addresses, and unmanaged addresses.
      • All possible networks: Adds all networks that are within the selected netmasks. The is enabled only when you split the /8 networks to /9 or /16 networks.
        Note that when you add a large number of networks, it could take a little longer for Grid Manager to display the networks.
    • Automatically create reverse-mapping zone: Select this check box to have the appliance automatically create reverse-mapping zones for the subnets.
  3. Click OK.

    Joining IPv4 Network s

Joining multiple networks into a larger network is the opposite of splitting a network. You can select a network and expand it into a larger network with a smaller netmask. A smaller netmask defines fewer networks while accommodating a larger number of IP addresses. Joining or expanding a network allows you to consolidate all of the adjacent networks into the expanded network. Adjacent networks are all networks falling under the netmask of the newly-expanded network. You can expand the selected network to a new size and add all other subnets into the new network. When you join networks, you need not define all small networks that cover the address spaces for a larger network.
Each of the adjacent networks join the expanded network and inherit the DHCP member configuration options of the selected network. The expanded network does not inherit the default router and broadcast address configurations of the adjacent networks. Those configurations are disabled by default. 

Note: The member assignment for the expanded network combines all member assignments of the joining networks. 

Note that the join and resize features work identically only when you have a single network. If the resize feature is disabled and if you have a single network object with additional new networks, then you must use the join feature to combine all networks.
To join or expand a network:

  1. From the Net Map or List panel, select a network, and then click Join from the Toolbar.
  2. In the Join Network editor, do the following:
    • Address: Displays the network address. You cannot modify this field.
    • Netmask: Displays the netmask of the network as you expand the network.
    • Join Network slider: Use the join network slider to specify the available subnet masks for the newly expanded network. Select a smaller netmask value, based on your requirements of the newly-expanded network. When you move the slider, a dialog box displays the total number of IP addresses and the IP address range of a selected subnet mask.
    • Automatically create reverse-mapping zone: Select this check box to configure the expanded network to support reverse-mapping zones Adding Grid Members.
  3. Click OK.

  Discovering Networks (Under Network Insight only)

Note: If the Discover Now button and other associated discovery elements are disabled on the Toolbar, it indicates that discovery is not enabled for the parent network of the selected network or IP, or that a discovery appliance (known as a Probe) is not associated with the network that you wish to discover.

To discover IPv4 or IPv6 networks:
1. From the Net Map or List panel, select a network, and then click Discover Now from the Toolbar. NIOS asks you to confirm that you wish to launch discovery on the selected network.
In the Net Map panel, you can click on IP addresses in the network being discovered. As new data becomes available, NIOS updates the Discovered Data section of the panel with any information found on the device associated with the selected IP.
For more information about requirements and discovery features, see the topics under About Network Insight.

  Deleting Networks

From the IPAM tab, you can delete multiple IPv4 and IPv6 networks. When you delete a network, all of its data, including all of its DHCP records, subnets, and records in its subnets, is deleted from the database and goes to the Recycle Bin, if enabled. Because of the potentially large loss of data that can occur when you delete a network, Grid Manager requires a confirmation to move the data to the Recycle Bin.
To delete IPv4 or IPv6 networks:

  1. From the Data Management tab, select the IPAM tab -> network check box. You can select multiple check boxes for multiple networks.
  2. Select Delete or Schedule Delete from the Delete drop-down menu.
  3. To delete the network now, in the Delete Confirmation dialog box, click Yes. To schedule a deletion, see About Extensible Attributes.
    The appliance puts the deleted network in the Recycle Bin, if enabled.