Traceflow fails with the error message, "dropped by no destination MAC in MAC Table."
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Traceflow fails with the error message, "dropped by no destination MAC in MAC Table."

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Article ID: 395472

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Updated On: 05-09-2025

Products

VMware NSX

Issue/Introduction

  • The default MAC address (02:50:56:56:44:52) of the NSX-T virtual distributed router was changed using the steps here: Change the MAC Address of NSX-T Virtual Distributed Router.
  • There is no datapath impact , however , traceflow fails with error "dropped by no destination mac in MAC Table." 
  • Log lines similar to the below are encountered on the NSX Manager in /var/log/proton/nsxapi.log.

    INFO providerTaskExecutor-64 TraceflowUtils 47833 MONITORING [nsx@6876 comp="nsx-manager" level="INFO" reqId="e20###02-9157-4##e-a##0-6f######f4b5" subcomp="manager" username="nsx_policy"] dump processing lrPort : LRPort[macAddress='02:50:56:56:44:52', logicalRouterId=9######c-7##e-4##9-a##1-bd########ec', linkedLogicalSwitchPortId='68####5d-d##d-4##f-b##8-###7ffe###8a', interfaceType=DOWNLINK', logicalSwitchId='fd#####d-03ca-####-8##c-9d########d1']

    Identifying problem across the system:

  • Confirm the virtual distributed router MAC address (vdr_mac) by running the API provided below :

    GET https://{{manager_ip}}/policy/api/v1/infra/global-config

    Sample output
    "mtu": 8800,
        "fips": {
            "lb_fips_enabled": true,
            "tls_fips_enabled": false
        },
        "l3_forwarding_mode": "IPV4_AND_IPV6",
        "uplink_mtu_threshold": 9000,
        "vdr_mac": "02:50:56:56:44:62", <<<<<<<<<<<<   vdr_mac changed from default.
  • Collect the output of Lr port table from the corfu database by running the command provided below as root on one of the NSX Manager node.

    root@nsx-mngr-01:/#corfu_tool_runner.py -n nsx -o showTable -t LrPort
  • Search if the mac address for any of the downlinks in the table is different from the one reported by global-config api.

Environment

VMware NSX 3.x and 4.x

Cause

  • The Traceflow tool, which tracks traffic flow and debugging, uses the LrPort( Logical Router Port) .

  • The virtual distributed router MAC address change is not propogated to the LrPort causing an issue with traceflow report.

Resolution

This is a known issue impacting VMware NSX.

Workaround:

  1. Perform a backup of NSX using the steps provided here:Start or Schedule Backups

  2. Download jar file (libport-mac-migration-lib.jar) attached to the article.

  3. Verify MD5 checksum of the downloaded file MD5: '674c5ddfa4c205c4933f35bed3c4ab0d'

  4. Copy the jar file in temporary folder 'tmp' in NSX manager node.(In case of Federation setup copy to one node in each site).

  5. Run the custom jar file (libport-mac-migration-lib.jar) to edit the MAC entries in LrPort using the command provided below:

    root@nsx-mngr-01:/tmp# java -cp "libport-mac-migration-lib.jar:/opt/vmware/proton-tomcat/webapps/nsxapi/WEB-INF/lib/*:/usr/tomcat/lib/*" -Dcorfu-property-file-path=/opt/vmware/proton-tomcat/conf/ufo-factory.properties -Djava.io.tmpdir=/image/corfu-tools/temp com.vmware.nsx.management.migration.impl.PortMacMigration

     

  6. Validate the mac address for all of the downlinks in the Lr table is same as reported by global-config api by checking the Lr port table.

Additional Information

If you are contacting Broadcom support about this issue, please provide the following:

  • NSX Manager support bundles.
  • Text of any error messages seen in NSX GUI or command lines pertinent to the investigation.

Handling Log Bundles for offline review with Broadcom support

Attachments

libport-mac-migration-lib.jar get_app