When updating from to 5.x to 6.1.x code, SSR is unable to bind accelerated networking interfaces.

Your routers may show admin down on lan and wan interfaces. 

Interface errors such as the following seen in highway logs:

highway[12812]: Failed to Add device interface "lan", device-port 2, of type Ethernet, disabling the resource due to "EthDeviceRXQueueException: Error [-12: Cannot allocate memory] configuring receive queue 0 out of 1 queues for ethernet device interface "lan", device-port 2, of type Ethernet, dpdk-port: 1

Stopping and starting 128T has no effect.

Restarting the vms in Azure, may resolve the issue in some cases, but it is not guaranteed.

In some cases, no action is performed and the router recovers after a period of time.

The issue can also present when MTU is configured to be greater than 2000.

Rolling back resolves the immediate problem, restoring the original 5.x configuration.

The issue is resolved in 6.2.3-r2.