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Network and Subnet

A Network is a virtual private network on LANIT Cloud — analogous to a VPC on other platforms. Each account can create several independent Networks to separate workloads (production, staging, internal, DMZ…). Inside a Network you create one or more Subnets — the specific IP ranges handed out to VMs.

Terminology​

ConceptMeaning
NetworkInternal virtual network, not routed directly to the Internet
SubnetA CIDR range inside a Network, handed out to VMs via DHCP or as a static IP
GatewayThe subnet's exit IP (usually the first or last address of the range)
DHCPAuto-assign IPs to VMs that attach to the subnet
Allocation PoolLimits the IP range that DHCP can hand out (reserves the rest for static IPs)

Create a Network​

Step 1. Open the Network page​

Go to Network → Networks and click + Create Network.

Networks page with the Create Network button

Step 2. Name the Network​

Type a memorable name (e.g. prod-net, staging-net, dmz-net) in Tên Network, optionally add a Mô tả (description), then click Create Network.

Network name form

The new Network has no subnet yet — add a subnet before VMs can attach to it.

Add a Subnet to the Network​

Step 1. Open the Create Subnet page​

In the Network list, click the + button next to the Network — the portal opens a dedicated Tạo subnet (Create subnet) page, not a dialog.

Add subnet button on a Network

Step 2. Configure the subnet​

FieldMeaningExample
Tên subnetMemorable nameapp-tier
Địa chỉ networkCIDR for the subnet192.168.100.0/24
GatewayInternal gateway IP. Leave empty and the system uses the first usable IP in the CIDR192.168.100.1
Tắt gatewayTick if the subnet has no gateway (network isolation, rare)–
Bật DHCPEnable to auto-assign IPs to VMs (on by default)On
Allocation poolsDHCP-managed IP range — click + Thêm allocation pool to add more ranges10.0.0.10 – 10.0.0.200
DNS serverDNS servers for VMs on this subnet — pre-filled with 8.8.8.8 and 1.1.1.1 by default, editable8.8.8.8, 1.1.1.1
Host routesStatic routes added to VMs — click + Thêm host route to add more–

Subnet configuration form

Avoid default-gateway conflicts

A VM attached to multiple subnets that all have a gateway will end up with multiple default routes → unpredictable routing and possibly lost connectivity. Safe rule:

  • One default gateway per VM — only the "Internet-bound" subnet should have a gateway.
  • Other internal subnets tick Tắt gateway, or simply don't attach them to that VM.

Step 3. Confirm​

Click Tạo at the bottom of the page. The new subnet appears under Subnets on the Network's detail page — click into the Network to view, edit or delete it. From now on, VMs can attach to it during creation or via Network Interface.

Subnet created inside the Network

Common topologies​

A single subnet​

For small projects — all VMs share 10.0.0.0/24, leave through the Router with S-NAT enabled.

Application + database split​

  • app-subnet (10.0.1.0/24) — app VMs, gateway on, Floating IPs attached.
  • db-subnet (10.0.2.0/24) — database VMs, no Floating IP, no gateway → only the app VMs in the same Network can reach them.

Dedicated management network​

Add mgmt-subnet (10.0.99.0/24) for SSH/RDP and monitoring, separate from the data plane to shrink the attack surface.

See also​