About the Ports field on the IP Switch (cmdb_ci_ip_switch) tableIssue <!-- /*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; max-width: 100%; color: #000; } .kb-wrapper p { margin: 0 0 10px 0; } This article describes what the Ports field on the IP Switch (cmdb_ci_ip_switch) configuration item (CI) represents and how ServiceNow Discovery populates it during the discovery process. 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: ; } } .kb-wrapper { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; max-width: 100%; color: #000; } .kb-wrapper p { margin: 0; } 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; max-width: 100%; color: #000; } .kb-wrapper p { margin: 0 0 10px 0; } The Ports field is populated from a Bridge Management Information Base (MIB) object identifier (OID) queried via Simple Network Management Protocol (SNMP) during the Discovery process. The value represents the device-reported port capacity of the switch, not the number of currently active or connected interfaces. 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; max-width: 100%; color: #000; } .kb-wrapper p { margin: 0 0 10px 0; } .kb-wrapper h3 { font-family: Lato, sans-serif; font-size: 12pt; font-weight: 900; color: #032D42; border-bottom: 2px solid #e8fce4; padding-bottom: 4px; margin: 22px 0 10px 0; } .kb-wrapper ul { padding-left: 20px; margin: 8px 0 14px 0; } .kb-wrapper ul li { font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; margin-bottom: 4px; } .kb-wrapper code { background: #e6f0f5; color: #032D42; border: 1px solid #b8cfd8; border-radius: 3px; padding: 1px 5px; font-family: 'Courier New', monospace; font-size: 10.5pt; } .kb-wrapper .note { border-left: 4px solid #52B8FF; background: #e6f4ff; padding: 10px 16px; margin: 14px 0 18px 0; font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; } .kb-wrapper ol.steps { list-style: none; counter-reset: step-counter; padding-left: 0; margin: 10px 0 18px 0; } .kb-wrapper ol.steps > li { counter-increment: step-counter; display: flex; align-items: flex-start; margin-bottom: 16px; font-family: Lato, sans-serif; font-size: 12pt; line-height: 1.7; } .kb-wrapper ol.steps > li::before { content: counter(step-counter); background: #032D42; color: #63DF4E; font-family: Lato, sans-serif; font-size: 10pt; font-weight: 900; min-width: 26px; height: 26px; border-radius: 50%; display: flex; align-items: center; justify-content: center; margin-right: 12px; flex-shrink: 0; margin-top: 3px; } What the Ports field represents The Ports field (cmdb_ci_ip_switch.ports) stores the value of dot1dBaseNumPorts, an object defined in the Bridge MIB (RFC 4188) for managing network bridges and switches. OID: 1.3.6.1.2.1.17.1.2 Full MIB path: iso.org.dod.internet.mgmt.mib-2.dot1dBridge.dot1dBase.dot1dBaseNumPorts The value represents the total number of ports present on the bridge or switch as reported by the device—total port capacity, not a count of currently active, connected, or link-up ports. The count includes physical and logical ports that are managed by the Bridge MIB or participate in the Spanning Tree Protocol (STP). Note: The Ports field does not reflect the current number of active or link-up interfaces. For a count of discovered network interfaces, see the physical_interface_count field on the same CI record. This field is populated separately from network adapter relationships discovered during the same run. How pattern-based Discovery collects this value The value is collected through two shared libraries called in sequence within the Network Switch ITOM pattern library—and within the Network Router ITOM pattern library for dual-role devices: SNMP Classify Initialization shared library — A step named Get dot1dBaseNumPorts variable runs an SNMP GET against OID 1.3.6.1.2.1.17.1.2 and stores the result in the pattern variable dot1dBaseNumPorts. A subsequent step, Set isSwitch variable, evaluates this value: if it is non-empty and non-zero, the device is classified as a switch (isSwitch = true), enabling shouldRunSwitchLogic for the remainder of the pattern run. SNMP - Switching shared library — Runs after classification and processes switching-specific data, including VLAN and port table data. Insert number of ports in cmdb_ci_ip_switch step — When shouldRunSwitchLogic is set to true, this step writes the value of dot1dBaseNumPorts to cmdb_ci_ip_switch[*].ports. How legacy probe-based Discovery collects this value The SNMP Switching probe (handler: SwitchingHandler, stage: explore) queries mgmt.mib-2.dot1dBridge.dot1dBase.dot1dBaseNumPorts directly, along with the full dot1dBasePortTable and the MAC forwarding table (dot1dTpFdbTable). The SwitchingHandler processes the response and populates the Ports field on the switch CI. 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