When ServiceNow Discovery scans an unassigned IP address (an IP with no host responding), here is what happens:
1. No Response Detected
ServiceNow will attempt to probe the IP using protocols like:
ICMP (ping)
SNMP
WMI (for Windows)
SSH (for Unix/Linux)
Since there is no device assigned to the IP, all these probes will fail, and the IP will be marked as unreachable.
2. Error or Status Logged
In the Discovery logs and status (available under Discovery Status or Discovery Log), you will typically see:
Classification failed
No response from IP
Could not identify host type
No probes responded
The log entry may look like:
Could not classify IP x.x.x.x: No response from IP
or
Host unreachable: All probes failed
3. Result in CMDB
No CI will be created.
The IP may be recorded in the cmdb_ip_address table as an unreachable IP, depending on your settings.
4. Mid Server Behavior
The MID Server will send out probes but will not receive any valid response back. The MID will not raise an exception but will log it as a non-responsive host.
Summary
ServiceNow Discovery will mark the IP as unreachable.
No CI is created, and errors will be logged as “no response” or “classification failed”.
You can find these logs under Discovery Status > Devices or Discovery Log.
