Discovery: Device SNMP sysName Differs from DNS NameIssue <!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } In Discovery payloads for SNMP-based devices, the hostname returned for the SNMP sysName is different from the hostname returned by the DNS lookup. Symptoms<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } .kb-wrapper ul { margin: 8px 0 8px 24px; padding: 0; } .kb-wrapper li { margin-bottom: 4px; } The SNMP sysName value in the Discovery payload does not match the DNS name (PTR record) for the same device.When the two identifiers conflict, Discovery may misidentify the device, leading to incorrect naming or duplicate CI entries in the CMDB. Facts<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } .kb-wrapper ul { margin: 8px 0 8px 24px; padding: 0; } .kb-wrapper li { margin-bottom: 4px; } .kb-wrapper code { font-family: 'Courier New', Courier, monospace; font-size: 10.5pt; background-color: #e6f0f5; color: #032D42; border: 1px solid #b8cfd8; border-radius: 3px; padding: 1px 5px; } A device's SNMP sysName (OID 1.3.6.1.2.1.1.5.0) is a locally configured string that can be manually set and changed on the device itself, independent of any external naming conventions.The DNS name is managed externally through DNS servers and resolves IP addresses to hostnames via PTR records.Because these two identifiers are maintained independently, they can legitimately differ — this is expected behavior, not a Discovery defect. Release<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } All Releases Cause<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } .kb-wrapper ul { margin: 8px 0 8px 24px; padding: 0; } .kb-wrapper li { margin-bottom: 4px; } The SNMP sysName and DNS name are maintained independently and can diverge for several reasons: The device hostname has been manually configured to a value that differs from its DNS name.The DNS server has not yet propagated a recent hostname change, causing a temporary mismatch.The SNMP sysName has not been explicitly set and defaults to a generic model name, while DNS provides a specific hostname. Resolution<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } .kb-wrapper ul { margin: 8px 0 8px 24px; padding: 0; } .kb-wrapper li { margin-bottom: 4px; } .kb-wrapper .steps-list { list-style: none; counter-reset: step-counter; margin-left: 0; padding: 0; } .kb-wrapper .steps-list > li { counter-increment: step-counter; display: flex; align-items: flex-start; gap: 12px; margin-bottom: 10px; } .kb-wrapper .steps-list > li::before { content: counter(step-counter); display: inline-flex; align-items: center; justify-content: center; min-width: 26px; height: 26px; border-radius: 50%; background-color: #032D42; color: #63DF4E; font-weight: 900; font-size: 11pt; flex-shrink: 0; margin-top: 2px; } .kb-wrapper .steps-list .step-content { flex: 1; } .kb-wrapper .steps-list .step-content ul { margin: 6px 0 0 20px; list-style: disc; } .kb-wrapper .steps-list .step-content ul li { display: list-item; margin-bottom: 3px; } .kb-wrapper .steps-list .step-content ul li::before { display: none; } Align the SNMP sysName and DNS name so that Discovery can consistently identify the device, then re-run Discovery to update the CI. Use SNMP tools to query the device's current sysName value and confirm whether it differs from the DNS hostname. Resolve the mismatch using one or both of the following approaches: Update the device's SNMP sysName to match the DNS hostname.Update the DNS reverse (PTR) record to match the device's sysName. After making changes, run a new Discovery against the device to update the Configuration Item (CI) in the CMDB. Related Links<!-- /*NS Branding Styles*/ --> .ns-kb-css-body-editor-container { p { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } span { font-size: 12pt; font-family: Lato; color: var(--now-color--text-primary, #000000); } h2 { font-size: 24pt; font-family: Lato; color: var(--now-color--text-primary, black); } h3 { font-size: 18pt; font-family: Lato; color: var(--now-color--text-primary, black); } h4 { font-size: 14pt; font-family: Lato; color: var(--now-color--text-primary, black); } a { font-size: 12pt; font-family: Lato; color: var(--now-color--link-primary, #00718F); } a:hover { font-size: 12pt; color: var(--now-color--link-primary, #024F69); } a:target { font-size: 12pt; color: var(--now-color--link-primary, #032D42); } a:visited { font-size: 12pt; color: var(--now-color--link-primary, #00718f); } ul { font-size: 12pt; font-family: Lato; } li { font-size: 12pt; font-family: Lato; } img { display: ; max-width: ; width: ; height: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; color: #000000; max-width: 100%; } .kb-wrapper p { margin: 8px 0; } .kb-wrapper .related-links a { color: #032D42; text-decoration: underline; } .kb-wrapper .link-disclaimer { font-size: 10pt; font-style: italic; margin: 2px 0 10px 0; color: #444; } SNMP support for Discovery — ServiceNow Documentation