Legacy Discovery identifiers

The following legacy identifiers are included in the ServiceNow base system.

All new instances use identifiers from the CMDB Identification and Reconciliation framework. Upgrades from pre-Geneva versions still preserve the legacy identifiers, but you can switch to the new identifiers using a property: glide.discovery.use_cmdb_identifiers. If you upgraded from a pre-Geneva version, you must manually add this property and set it to true to use the new identifiers. If you upgraded from Geneva or later releases, this property is available in the System Properties [sys_properties] table. To preserve functionality in custom legacy identifiers, convert them to the new CMDB identifier rules format before enabling this property. The system does not reconfigure your custom identifiers to the new framework automatically.
Note: When Service Mapping is active, the new identifiers from the CMDB Identification and Reconciliation framework are always used regardless of the property value.
Table 1. Legacy identifiers
Identifier Description Details
Serial Number Table & Class Name Identify CIs in the CMDB based on serial number(s) in the serial number table and sys_class_name. This identifier matches the discovered serial number against the serial_number in the Serial Number [cmdb_serial_number] table. If the discovered serial number matches a CI in the cmdb_serial_number table and the class name, the CI is declared identified. Note that in the base system, Discovery populates the cmdb_serial_number table. Therefore, this identifier is important for Discovery to use to find the CIs it has discovered in the past (assuming these were valid serial numbers).

For more information, see Serial number types for discovered devices.

Serial Number & Class Name Identify CIs in the CMDB based on the serial_number field and matching sys_class_name. This identifier matches the discovered serial numbers against the serial number field in the base CI record. If a discovered serial number and class type (sys_class_name) matches a CI, that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class. For example, a computer and a printer have the same serial number, but since their class names differ, Discovery does not identify them as the same CI. Typically, imported data has the serial number field completed, but no matching value in the cmdb_serial_numbertable. This identifier solves the issue of Discovery finding imported data in the CMDB.
Name & Class Name Identify CIs in the CMDB based on name field and matching sys_class_name. This identifier matches the discovered name against the name field in the base CI record. If a discovered name and class type (sys_class_name) matches a CI, then that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class. For example, a computer and a printer have the same name, but since their class name differs, Discovery will not identify them as the same CI.
Network Identify CIs in the CMDB based on IPs and MAC Address(es) in the network adapter table. This identifier matches the discovered network adapters against those in the Network Adapter [cmdb_ci_network_adapter] table, using the IP address and MAC address. If all the discovered network adapters match a CI in the network adapter table, then the CI is declared identified.
Network & Class Name Identify CIs in the CMDB based on the mac_address field and the ip_address field and matching sys_class_name. This identifier matches the discovered IP address and MAC address of the base CI against those in the base CI record. If a discovered IP address, MAC address and class type (sys_class_name) matches a CI, then that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class.
MAC Address & Class Name Identify CIs in the CMDB based on the mac_address field and matchingsys_class_name. This identifier matches the discovered MAC address of the base CI against those in the base CI record. If a discovered MAC address and class type (sys_class_name) matches a CI, then that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class.
IP Address & Class Name Identify CIs in the CMDB based on the ip_address field and the matching sys_class_name. This identifier matches the discovered IP address of the base CI against those in the base CI record. If a discovered IP address and class type (sys_class_name) matches a CI, then that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class.
MACAddress Identify CIs in the CMDB based on MAC Address(es) in the network adapter table. This identifier matches the discovered MAC address of the base CI against those in the base CI record. If a discovered MAC address and class type (sys_class_name) matches a CI, then that CI is declared identified. The matching class name requirement means that Discovery will not identify CIs that are not in the same class.
Generic Serial Number Identify CIs in the CMDB based on serial_numberfield. This identifier matches the discovered serial number against the serial number field in the base CI record. If a discovered serial number matches a CI, then that CI is declared identified. Note here that the matching class name is NOT a requirement, which means that Discovery will identify CIs even if they are not in the same class. For example, a computer and a printer have the same serial number, but even though their class name differs, Discovery will still identify them as the same CI.
Generic Network Identify CIs in the CMDB based on the mac_address field and the ip_address field. This identifier matches the discovered IP address and MAC address of the base CI against those in the base CI record. If a discovered IP address and MAC address matches a CI, then that CI is declared identified. The matching class name is NOT a requirement, which means that Discovery will identify CIs that are not in the same class.
Generic Name Identify CIs in the CMDB based on name field. This identifier matches the discovered name against the name field in the base CI record. If a discovered name matches a CI, then that CI is declared identified. The matching class name is NOT a requirement, which means that Discovery will identify CIs that are not in the same class.
Generic MAC Address Identify CIs in the CMDB based on MAC addressfield. This identifier matches the discovered MAC address of the base CI against those in the base CI record. If a discovered MAC address matches a CI, then that CI is declared identified. The matching class name is NOT a requirement, which means that Discovery will identify CIs that are not in the same class.
Generic IP Address Identify CIs in the CMDB based on IP address field. This identifier matches the discovered IP address of the base CI against those in the base CI record. If a discovered IP address matches a CI, then that CI is declared identified. The matching class name is NOT a requirement, which means that Discovery will identify CIs that are not in the same class.