Learn how to map your network automatically using Intermapper's Autodiscovery feature.
Scan and map your network automatically with Intermapper's auto-discovery feature. Here's how.
Intermapper's auto-discovery feature makes it easy to get started mapping your network. But before you start, two important points.
First, Intermapper may ping or query every device address on a network. If your network has an intrusion detection system, auto-discovery may trigger your intrusion alarms. Be sure to check with the network manager before using this feature.
During auto-discovery, Intermapper limits its queries to two per second so that it doesn't overload any networks. A Class C network with 254 addresses takes just over two minutes. With 65,535 addresses, it takes just under ten hours to scan a Class B subnet completely. A Class A subnet with 17 million addresses would obviously take significantly longer. If you have a large network, use the Add Network command to add a subnet. Then use the Scan Network command to do an auto-discovery on that subnet. This is covered in more detail in the mapping large networks tutorial.
Let's get started. First, create a new map. From the File menu, choose New. Enter a map name and click Next. Click the radio button to select auto-discovery. As you can see, you can also choose to enter devices manually, or you can import devices from a file.
Enter an IP address for the network you want to scan. You can also use a domain name. If you have SNMP devices on your network, enter a SNMP community string. The default string is public. Intermapper discovers using only one community string at a time. If the SNMP devices on your network use different community strings, you will need to discover them in separate steps. Enter a number of hops you want to stay within. To limit the types of devices you want to scan for, click Edit Filters.
Active queries all IP addresses and adds a device for each one that responds. Named looks up each address in the DNS and adds a device for each one it finds. SNMP sends an SNMP get request to every IP address and adds a device for each one that responds. I've unchecked Automatically Layout so you can see what happens. I'll get back to this in a minute. I'll switch to list view for a moment, and you can see the devices being added.
So, you can see the devices that have been discovered. Normally, the next step is to arrange the discovered devices in whatever ways are useful for your particular network. This is a large subject and is covered in another tutorial. The automatic layout feature uses the organic layout algorithm. If I had chosen layout automatically, the map would be laid out this way as devices are discovered.
Select All, then use Organic from the Arrange submenu, which you'll find in the Format menu. If you have a large network, use the Add Network command to add a subnet. Then use the Scan Network command to do an auto-discovery on that subnet. This is covered in more detail in the mapping large networks tutorial.
That's auto-discovery in a nutshell. For more information, see the user guide available from Intermapper's Help menu.