App is up, but Spoke 2 can't reach it
vm-spoke2 can't reach the app on vm-spoke1 at 443.
- Get vm-spoke2 reaching the app on vm-spoke1 (443) through fw-hub
- Keep UFW running on vm-spoke1broken
- Keep SSH from vm-spoke2 to vm-spoke1 blockedbroken
- Don't peer the spokes to each otherbroken
Background
"nginx is running and answers locally," says the app team. Still, since the hub was rebuilt, vm-spoke2 can't reach the app on vm-spoke1 at 443. Spoke-to-spoke traffic goes through fw-hub at 10.0.2.4. The spokes aren't peered to each other. SSH to vm-spoke1 is for the hub's admins only, and UFW stays on.
- 1See it fail
Prove the problem yourself before you change anything. Reports are often wrong.
VM commands forVMs: Linuxssh vm-spoke2What's this?
Opens a shell on vm-spoke2, 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.
nc -zv 10.1.1.4 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 words10.1.1.4where to connect443the port to try
Ticks off when the test runs on vm-spoke2.
- 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-spoke2 → vm-spoke1:443should work: not workingvm-spoke2 → vm-spoke1:22should stay blocked: blocked