Layer 2 Overview¶

Equinix Metal™ servers are configured with a Layer 3 network configuration by default, but many bare metal environments benefit from Layer 2 networking to manage services like DHCP and routing within a private network. To support these use cases we’ve developed a feature that allows users to add Layer 2 virtual networks to their Equinix Metal infrastructure. VLANs can then connect your servers to each other or connect your servers to other infrastructure, like Equinix Fabric.

You can attach servers in the same project within the same data center to Layer 2 virtual local area networks (VLANs). This feature is available in all data centers for no added fee.

Functional Description¶

The 2-port NIC is configured with a single bond, namely bond0, with both interfaces eth0 and eth1 as members of the bond in the default Layer 3 mode.

In bonded modes, VLANs can be attached to the bonded network interface. Bonded modes offer redundancy and high-availability by supporting traffic across the 2 switches. An outage, maintenance, or reboot of one of them will not cause network interruptions.

In unbonded modes, the switch ports serving each of your server's NICs may be independently configured to switch between networking modes enabling you to attach VLANs to the ports. This does introduce a single point of failure on the upstream switch or the network interface. An outage, maintenance, or reboot of one of the ports will cause network interruptions.

Network Configuration Types¶

When converting from Layer 3 to another network type there are a few possible configurations to choose from:

Hybrid Bonded mode - Both Layer 3 and Layer 2 is supported on the bonded interface. VLANs can be attached to the bonded interface.
Hybrid Unbonded Mode - One network interface is removed from the bond and placed in Layer 2 mode. VLANs can then be attached to this interface for Layer 2 connectivity. This preserves Layer 3 connectivity to the server via bond0, so it can be accessed via the public IP.
Layer 2 Bonded mode - This mode converts the bonded network interface to pure Layer 2 mode. This means all access to the public Internet is lost, and the host can only be reached by the Serial Over SSH (SOS) console. In this configuration the network bond is intact, so only one network interface will be available for attaching VLANs.
Layer 2 Unbonded mode - This mode is similar to the Layer 2 Bonded mode configuration, except the network bond is also dismantled, providing two network interfaces available for VLANs. All access to the public Internet is lost, and the host can only be reached by the Serial Over SSH (SOS) console.

Layer 2 Feature Availability¶

The t1.small.x86, c1.small.x86, and x1.small.x86 servers do not support Layer 2 features. These servers support Layer 3 only.
Hybrid Bonded mode is only available in Equinix IBX locations. Servers in Equinix Metal legacy facilities are not able to use Hybrid Bonded mode.

Enabling Layer 2 Modes¶

This is a high-level overview of the steps to enable and configure Layer 2 networking on your Equinix Metal servers.

Create a VLAN.
Change the networking mode and attach the VLAN to your server. In Hybrid Bonded mode, you only have to attach a VLAN to the bonded interface. For Hybrid Unbonded mode and the Pure Layer 2 modes, you have to change the networking mode first.
Configure the server to properly use the VLAN and interfaces at the operating system level. This step varies by networking mode and operating system.
(Optional) Set a Native VLAN. Unbonded modes support un-tagged packets and native VLANs.