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VLANs let you build a private Layer 2 network between your servers over their secondary (non-public) network interfaces. Servers on the same VLAN can talk to each other directly, without the traffic ever touching the public internet.

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How it works

VLANs are defined logically first and only materialize on the network when they’re actually needed:
  1. You create a VLAN (via the API or dashboard).
  2. You attach servers to it.
  3. Once two or more servers are attached, Rackdog allocates a real VLAN on the switch and connects the servers to it.
  4. The servers can now reach each other over their private interfaces.
A VLAN with a single server attached exists in your account but has no underlying network: there’s no one to talk to, so nothing gets provisioned on the switch until a second server joins.

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Lifecycle behavior

  • Server removal. Deleting a server automatically detaches it from any VLAN.
  • Down to one server. The VLAN stays allocated internally, but there’s no connectivity until another server joins.
  • Down to zero servers. The underlying network is cleaned up. The VLAN still exists from your perspective and can be reused when you attach servers again.

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Creating a VLAN

VLANs are managed through the API today: create the VLAN, attach servers, and manage membership there. Dashboard support is on the way. Not every server supports VLAN networking. Use the API to list VLAN-capable servers before attaching.

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Private networking

VLAN traffic flows over each server’s secondary network interface. The primary interface handles public networking and is not used for VLAN traffic.

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IP configuration

Rackdog does not hand out IP addresses inside your VLAN. You pick the subnet and configure addresses on each server yourself.

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Example (Ubuntu / Netplan)

Server 1: 
10.10.10.1/24
Server 2: 
10.10.10.2/24
Apply the Netplan config on both servers and they’ll be able to reach each other over the VLAN.

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Things to know

  • VLANs operate at Layer 2 only. There’s no routing by default.
  • IP addressing, subnet design, and any routing between VLANs are your responsibility. If you need to connect multiple VLANs, use a dedicated server as the router.

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A typical workflow

  1. Create a VLAN via the API.
  2. Attach two or more servers.
  3. Configure private IPs on each server.
  4. Verify with a ping between them.

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Good habits

  • Attach at least two servers so the VLAN actually activates.
  • Use consistent subnetting across servers in the same VLAN.
  • Keep private addressing organized, for example by environment or service.

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When to use VLANs

Reach for a VLAN when you want private traffic between servers, isolation from the public internet, or a custom topology across your fleet.