r/HyperV • u/ThePerpetualsmoker • 15d ago

Node stuck unable to join Hyper-V cluster — NetFT adapter flapping

Having trouble re-joining a host back to a cluster, hoping someone can give me some insight because I cannot find many similar issues:

One node (call it Node A) cannot rejoin the cluster after being drained/rebooted for routine maintenance. The other two nodes are completely healthy, holding quorum, roles all online. Node A's Cluster Service runs locally but every join/form attempt ends the same way:

Get-ClusterNode shows Node A stuck in Down state (occasionally rolls back to no record at all)

Cluster log: repeated [QUORUM] Fail to form/join a cluster in 6-7 minutes → FatalError: join/form timeout (status = 258) (WAIT_TIMEOUT)

Live event log: Event 1650 (lost/established UDP connection on the management endpoint) and Event 5417 ("Cluster Service has terminated due to a fatal error... Error Code: 3473458" = ERROR_CLUSTER_JOIN_ABORTED), repeating in a loop

The NetFT pseudo-adapter (Microsoft Failover Cluster Virtual Adapter, shows as Local Area Connection* N in Get-NetAdapter -IncludeHidden) cycles Disconnected → Up → Disconnected on an irregular ~10-150 second cadence, indefinitely

Meanwhile vEthernet (Management) underneath it stays Up continuously the entire time — confirmed via a parallel live polling loop. NIC RX/TX counters on the same adapter climb steadily throughout, never stalling

3 Upvotes

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3

u/msav30 15d ago

Have you checked the physical nic driver update and settings match the vnic issue tends to be an issue on the. Physical nic that's where I would start

1

u/Jkabaseball 14d ago

We had a similar issue. Turns out I set up the first 2 hosts with drivers directly from Dell. Person working on the next one pulled driver from intel directly. First time ever running into a driver issue.

1

u/BlackV 14d ago

I'd agree with the others

Make sure drivers and firmware are identical across the nodes

Otherwise nuke and rebuild