"java.lang.NullPointerException" Observed When Performing MTU Configuration Checks or Editing Tunnel Endpoints under Global Fabric Settings
Article ID: 420469
Updated On:
Products
Issue/Introduction
When performing any of the following actions under Global Fabric Settings, the operation fails with a generic error: java.lang.NullPointerException
- Running "Check Now" for MTU configuration validation
- Editing and setting the Tunnel Endpoint (TEP)
- Editing and setting the Remote Tunnel Endpoint
The error occurs consistently when attempting MTU validation or editing TEP/Remote TEP configuration.
The following log entries are recorded in /var/log/proton/nsxapi.log on the NSX Manager node:
2025-10-02T05:53:22.722Z INFO http-nio-127.0.0.1-7440-exec-40 GlobalConfigPluginServiceImpl 76889 FABRIC [nsx@6876 comp="nsx-manager" level="INFO" reqId="6###c727-####-4c3d-####-886######290" subcomp="manager" username="admin"] Fetched global configs SwitchingGlobalConfigDto{physicalUplinkMtu='null', uplinkMtuThreshold='9000', globalReplicationModeEnabled='null', remoteTunnelPhysicalMtu='null', arpLimitPerLr='50000', super{GlobalConfigsDto{super{ManagedResource{resourceType='SwitchingGlobalConfig', aCreateUser='system', aCreateTime='1670234889194', aLastModifiedUser='system', aLastModifiedTime='1670234889194', aSystemOwned='true', aProtection='null', id='ed####55-3f62-####-####-70a#####0c43', displayName='ed####55-3f62-####-####-70a#####0c43', description='null', tags='null', super{RevisionedResource{aRevision='0', super{Resource{aSelf='null', aLinks='null', aSchema='null'}}}}}}}}}2025-10-02T05:53:26.185Z INFO http-nio-127.0.0.1-7440-exec-51 GlobalConfigPluginServiceImpl 76889 FABRIC [nsx@6876 comp="nsx-manager" level="INFO" reqId="8c###b22-####-428f-####-d6e7#####f67" subcomp="manager" username="admin"] Fetched global configs SwitchingGlobalConfigDto{physicalUplinkMtu='null', uplinkMtuThreshold='9000', globalReplicationModeEnabled='null', remoteTunnelPhysicalMtu='null', arpLimitPerLr='50000', super{GlobalConfigsDto{super{ManagedResource{resourceType='SwitchingGlobalConfig', aCreateUser='system', aCreateTime='1670234889194', aLastModifiedUser='system', aLastModifiedTime='1670234889194', aSystemOwned='true', aProtection='null', id='ed####55-3f62-####-####-70a#####0c43', displayName='ed####55-3f62-####-####-70a#####0c43', description='null', tags='null', super{RevisionedResource{aRevision='0', super{Resource{aSelf='null', aLinks='null', aSchema='null'}}}}}}}}}2025-10-02T05:53:26.186Z INFO http-nio-127.0.0.1-7440-exec-51 GlobalConfigPluginServiceImpl 76889 FABRIC [nsx@6876 comp="nsx-manager" level="INFO" reqId="8c###b22-####-428f-####-d6e7#####f67" subcomp="manager" username="admin"] Fetched global configs RoutingGlobalConfigDto{l3ForwardingMode='IPV4_ONLY', logicalUplinkMtu='1500', vdrMac='02:##:56:##:##:52', vdrMacNested='02:##:56:##:##:53', allowChangingVdrMacInUse='false', super{GlobalConfigsDto{super{ManagedResource{resourceType='RoutingGlobalConfig', aCreateUser='system', aCreateTime='1670234889194', aLastModifiedUser='system', aLastModifiedTime='1670234889194', aSystemOwned='true', aProtection='null', id='ed####55-3f62-####-####-70a#####0c43', displayName='ed####55-3f62-####-####-70a#####0c43', description='null', tags='null', super{RevisionedResource{aRevision='0', super{Resource{aSelf='null', aLinks='null', aSchema='null'}}}}}}}}}
Environment
VMware NSX
Cause
The issue occurs because the parameter SwitchingGlobalConfigDto.physicalUplinkMtu is set to null in the NSX configuration.
In standard NSX deployments (for example, version 4.2.1 and later), this value defaults to 1700 and cannot be null. However, older or upgraded environments may contain legacy configurations where this field was incorrectly allowed to remain unset (null).
When NSX Manager attempts to fetch or validate this configuration, the null value triggers a NullPointerException.
Resolution
The issue is resolved in NSX 4.2.3.2
Workaround :
The resolution involves manually adding valid MTU values to the Global Fabric Configuration.
To proceed:
Collect the Global Connectivity configuration details from the affected NSX Manager node by running the following GET API call:
GET https://<NSX-GM-IP>/policy/api/v1/infra/connectivity-global-config
Save the API response output for review.
Log a support case with the Broadcom Support team and attach the collected API output.
The support team will assist in validating and correcting the physicalUplinkMtu parameter in the global configuration database.
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