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Home > Success Center > Network Topology Mapper (NTM) > NTM - Knowledgebase Articles > Network Selection Discovery options

Network Selection Discovery options

Updated June 21, 2017


You can specify the range of IP addresses you want to discover with the NTM Discovery wizard. After IP nodes are discovered, you can select which ones you want to include on your map. The time it takes to complete a Discovery scan relies heavily on the range of IP addresses you specify. This article provides guidelines and steps to create Discovery ranges that will accurately discover the devices you want to map without including a large number of other devices.


NTM 2.2.2


The following lists Network Selection Discovery options from the most specific to the most general option:

Specific nodes

This option discovers only the nodes you specify by IP address. It is useful when you have an existing map and you want to add a specific node without having to discover a number of subnets or IP addresses. Add specific nodes by their IPv4 address or IPv6 address. Add the one node per line.

Discovery IP ranges

This option discovers only the nodes you specify by IP address range. The range can be any contiguous IP address block. Multiple ranges can be included to allow for discovery of non-contiguous ranges. Nodes outside the specified range will not be discovered and the Hop Count Discovery option is ignored for IP ranges.


For example, a discovery using the range to defines a contiguous discovery range including all possible IP addresses between .110.1.1 and
In contrast, a discovery including the starting address of and the ending IP address of along with an additional range of to will discover only those ranges and will not include the subnet between them.


IPv6 ranges are supported.


This option discovers the specified subnet and all networks directly connected to devices on the specified subnet.

For example, consider a discovery for the subnet with a subnet mask of If the discovery finds a router on the subnet that also has interfaces on and subnets, those subnets will also be scanned for devices and connectivity. Additional subnets connected to those devices on the new subnets are not scanned.


After discovering subnets, clear the checkbox next to a subnet to remove that subnet from your map. IPv6 subnets are supported.

Seed devices

This option discovers all subnets that the specified device is aware of. By adding hop counts, this option will discover devices several networks away. You can use a seed device to discover subnets, connectivity, and network devices throughout your network. A seed device must be a layer 3 switch or router. NTM will scan the connection to the indicated device and use that information to scan directly connected devices.


After discovering directly connected devices, NTM will discover devices on connected subnets to the extent you have indicated in the Number of Hops option.


IPv6 see device addresses are supported.


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