VM can't reach storage locked to selected networks
vm-app can't reach stdata01 on 443.
- Get vm-app through to stdata01 on 443
- Keep stdata01 denying by defaultbroken
Background
Security switched the storage account stdata01 to allow access only from selected networks, and tightened nsg-app on subnet-app the same week. vm-app, in vnet-app/subnet-app, now can't get to stdata01.blob.core.windows.net on 443. The account must stay locked to selected networks.
- 1See it fail
Prove the problem yourself before you change anything. Reports are often wrong.
VM commands forVMsssh vm-appWhat's this?
Opens a shell on vm-app, so the next commands run on that VM. In this lab it's a shortcut. In real Azure you'd connect through something like Azure Bastion, or SSH to an address you can reach.
nslookup stdata01.blob.core.windows.netWhat's this?
Asks the VM's DNS server what IP address a name points to. Run it on the VM that has the problem, because each VM can get a different answer.
nc -zv stdata01.blob.core.windows.net 443What's this?
netcat, a standard Linux tool. Tries to open a TCP connection and reports whether it worked.
-zonly check whether the port answers. Send no data-vprint the result in wordsstdata01.blob.core.windows.netwhere to connect443the port to try
Ticks off when the test runs on vm-app.
- 2Find where it stops
- 3Name the cause
- 4Fix it and test again
- 5Explain it
?
- Resource group, the outer dashed frame
- Virtual network, with its address space top right
- Subnet, with range and usable IPs (5 reserved)
- Network security group. A small shield on a VM's NIC means the NIC has one too
- Route table on the subnet
- VM Appliance Private endpoint
- Peering Connected Initiated or access off
- Goal working Goal broken, X marks where it stops
- Private DNS zone, dotted lines go to linked VNets
- Orange pulse: what your last command changed. Drag to pan, Ctrl and scroll to zoom.
vm-app → stdata01.blob.core.windows.net:443should work: not working