Discovery Best Practices

Follow the points below to ensure effective discovery of the network:

1. For simplicity, perform discovery in phases.
   • Begin with a small set of devices and ensure your discovery ranges, defined credentials, and seed routers are all correct.
   • Ensure that firewall gateways for any networks to be discovered allow discovery traffic through open TCP/UDP ports 161 and 162, to allow SNMP traffic.
   • Ensure that your discovery ranges, static IPs, and seed routers are associated with their correct network views. For initial discovery, your ranges and other discovery settings can simply be associated with the Network 1 network view, which is automatically created during appliance setup and is bound to the SCAN1 port on your Collector appliance. For more information, see Configuring Network Views.
   • Avoid defining large Discovery Ranges such as /8 or /16, and avoid defining more than 1000 ranges of any size. However, having a large discovery range and seed routers is a more effective discovery technique than using hundreds of small ranges. (You can change device group rankings in Settings icon > Setup > Discovery Settings). For more information, see Configuring Discovery Ranges.
   • For discovery using ping sweeps, avoid attempting ping sweeps of greater than /22 subnets. Ping sweeps use protocols other than ICMP and can incur delays in refreshing previously discovered devices. For information on Smart Subnet ping sweep, see Defining Group Data Collection Settings.
2. Include End-Host devices and Ethernet segments in discovery ranges.
   • Use the Exclude From Management setting on end-host segment discovery ranges to prevent unnecessary SNMP credential discovery against end hosts (Settings icon> Setup > Discovery Settings > Ranges tab > Discovery Mode menu).
   • Use Smart Subnet Ping Sweep for complete end-host discovery. For information on Smart Subnet ping sweep, see Defining Group Data Collection Settings.