Discovering Your Enterprise › Discovering Your Network Devices on Demand Using Classic Discovery › Discovery Creates Incorrect Subnets

Discovery Creates Incorrect Subnets

Symptom:

Classic Discovery runs for a long time and places devices under the wrong subnets. When I look at a subnet segment, I see incorrect devices, for example, devices with IP addresses from a different Class C network.

Solution:

When discovering a subnet with Classic Discovery, verify that the subnet mask is set correctly. The default subnet mask that Classic Discovery uses is 255.255.255.0. If the subnet mask is different, specify the -N subnet-mask parameter in the dscvrbe command, or set the subnet mask on the Discovery Wizard or Advanced Discovery Subnets Page in Unicenter MCC. Classic Discovery also retrieves subnet masks from a router if SNMP is enabled. Be sure that subnet masks are set correctly for all router interface cards that were discovered.