Azure w/ ExpressRoute.
We have a group of maintenance machines that shut down at night to reduce resources. Everything running fine for months. Yesterday, we came in to find several of the machines unreachable. They can be reached from within their Azure subnet, but not from elsewhere on the network.
After some troubleshooting, we noticed that they have lost all the BGP routes that normally show on their network interface. They only have their UDR for their local subnet.
We have a case open but it's getting bounced around in the finger-pointing game currently.
All working machines have their routes from BGP. It just got more urgent because a Production machine rebooted last night and now it is the same thing.
The NIC shows connected to the VNet, and the other NIC's connected to that VNet are working and effective routes show their routes from BGP.
We've tried to Redeploy the VM's thinking it was possibly an Azure host issue to no avail.