Floating IP
A Floating IP is a public IP that you attach flexibly to a VM. Unlike the internal IP (fixed inside the Subnet), a Floating IP:
- Attaches/detaches between VMs in seconds — no restart required.
- Stays with the account — the IP is the same whichever VM it's currently on.
- Required to reach a VM from the Internet (SSH, RDP, HTTP/HTTPS).
When do you need a Floating IP?
| Scenario | Floating IP needed? |
|---|---|
| SSH/RDP into a VM from the Internet | ✓ |
| Serve a public website directly from the VM | ✓ |
| Backend sitting behind a Load Balancer | ✗ (only the LB needs a public IP) |
| Internal VM (database, cache, worker) | ✗ |
| VM that only needs to call out to the Internet (API calls, pull updates) | ✗ — S-NAT through the Router already handles it |
Create a Floating IP
A Floating IP is billed on a subscription cycle — creating one goes through an order-confirmation and payment step, the same as creating a VPN Gateway.
Step 1. Open the Floating IPs page
Go to Network → Floating IPs and click + Create. The portal opens the Phân bổ Floating IP (Allocate Floating IP) page.
Step 2. Configure the Floating IP
| Field | Meaning |
|---|---|
| Pool (required) | Public network. The list only shows pools already attached to a Router with an External Gateway — if none is configured yet, this list is empty |
| Bandwidth (required) | Pick from the available bandwidth plans (not a free-typed number) |
| Description (optional) | A memorable note |
| Subscription | Prepaid billing cycle: 1 / 3 / 6 / 12 months |
Click Xác nhận (Confirm).
Step 3. Confirm the order and pay
The portal moves to the order page — review the monthly cost and confirm payment for the IP to be provisioned.
If the Pool dropdown has no options, it's almost always because the account's Router hasn't enabled an External Gateway pointing at that public network yet — enable it first, then come back to create the Floating IP.
Attach a Floating IP to a VM
Step 1. Pick Attach to server
In the Floating IPs list, click ⋯ next to an IP that's currently Chưa sử dụng (Unassigned) → Gán vào server (Attach to server).
Step 2. Pick the Port and Private IP
The Gắn Floating IP (Attach Floating IP) dialog asks for, in order:
| Field | Meaning |
|---|---|
| Địa chỉ IP (IP address) | The Floating IP to attach |
| Port được liên kết (Linked port) | The VM's Network Interface (port) that will receive this IP |
| Private IP | The specific internal IP on that port — this list only populates after a Port is picked |
Confirm in the dialog to finish.
The Floating IP becomes active immediately. Test with ping / ssh from your local machine.
Change the bandwidth
You can upgrade the bandwidth cap without detaching — the portal doesn't allow downgrading below the current tier.
Click ⋯ next to the IP → Đổi băng thông (Change bandwidth).
Pick a new plan (only tiers ≥ the current one are listed) and click Xác nhận (Confirm). This is also a billed action — the portal moves to the order page to confirm and pay before the new bandwidth takes effect.
Detach from a VM (keep the IP)
Click ⋯ next to the IP → Gỡ khỏi server (Detach from server).
The Floating IP returns to Chưa sử dụng (Unassigned), ready to be attached to another VM. Don't delete the IP — it keeps billing until it's fully released.
When refreshing a VM but you want to keep the same public IP (for DNS, third-party ACLs), just detach from the old VM → attach to the new VM. Downtime is only the rebind window.
Delete a Floating IP for good
Click ⋯ next to the IP → Xóa (Delete).
Unlike almost every other action on the portal, deleting a single Floating IP from the ⋯ menu happens the instant you click it — there's no confirmation dialog. Double-check you picked the right IP; this stops billing but the IP itself cannot be recovered.
Selecting multiple Floating IPs via checkbox and bulk-deleting does show a dialog, which requires ticking "Tôi xác nhận và hiểu hành động này không thể hoàn tác." (I confirm and understand this cannot be undone) before it lets you delete.
See also
- Router management — the Router needs an External Gateway for Floating IPs to work.
- Security Group — open the right ports so inbound traffic reaches the VM.
- SSH/RDP — use the Floating IP to sign in to the VM.