Configure subnet scan settings manually

IPAM uses SNMP and ICMP to scan and determine the status of your monitored network. You can select how IPAM automatically scans your network for changes.

1. Click Settings > All Settings > IPAM Settings > Manage Subnet Scan Settings.
2. Enter the transient period, or select Unlimited Duration.

   IPAM continuously scans all managed IP addresses on your network. If a device fails to respond to any SNMP or ICMP requests for the duration entered here, IPAM will change the status of the unresponsive IP address from Used to Available. Any associated custom attribute is overwritten. If Unlimited Duration is selected, unresponsive devices will retain the status of Used until manually updated.

3. You can assign transient scan intervals for individual subnets using Edit Subnet Properties on the Manage Subnets and IP Addresses page.

4. ICMP is used by default to scan your network subnets for changes. To configure ICMP:
   1. Enter the number of pings per address.
   2. Enter the delay between pings, and the ping timeout, in milliseconds, for ICMP requests on your network.
5. To configure SNMP to scan your network subnets:
   1. Select Enable SNMP Scanning in the SNMP Scanning section.
   2. Select Enable SNMP neighbor scanning.
      Neighbor Scanning will attempt to retrieve the status of a device that is not responding to ICMP by scanning the ARP table of a neighbor router to determine what IP addresses are active.
   3. Enter the number of SNMP retries.
   4. Enter the SNMP Timeout, in milliseconds, for SNMP requests on your network.
6. Click Save.

You can disable scanning on a per subnet basis. See Edit subnets for more information about editing individual subnet properties.