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Q-in-Q

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Q-in-Q is a technology that allows you to create multiple isolated segments within a single VLAN by adding an additional tag to the Ethernet packet header.

With Q-in-Q enabled on a Selectel network, you can pass your VLAN IDs on a port and tags will be delivered over the private network between your servers.

Q-in-Q can only be enabled for a private network. Setting up Q-in-Q on a private network is required:

  • for Direct Connect service operation when a trunk port is configured on the operator's side;

  • To configure a trunk port in VMware ESXi on a dedicated server with VMware;

  • to use different VLAN segments on a dedicated server on which virtual servers are deployed. In this case, the dedicated server is privately networked with the virtual server using a global router. Tagged traffic with your VLAN IDs is terminated on the global router and then routed to the virtual server.

Customize Q-in-Q

  1. Enable Q-in-Q on the switch port.

  2. Select a private subnet.

  3. Configure the network interfaces on the server.

1. Enable Q-in-Q on the switch port

When Q-in-Q is enabled, there may be a brief private network down time for servers on the selected VLAN.

  1. Create a ticket with a request to enable Q-in-Q. In the ticket, specify:

    • VLAN numbers can be viewed in the control panel: from the top menu, click Products → Dedicated Servers → Network → VLAN tab → VLAN column;

    • pools where VLANs are located can be viewed in the control panel: in the top menu, click Products → Dedicated Servers → Network → VLAN tab → Pool column.

  2. Wait for a Selectel employee to respond that Q-in-Q is enabled.

2. Select a private subnet

Select an unoccupied subnet whose IP addresses will be used to configure network connectivity. See Standard Private IP Address Ranges for details.

3. Configure the network interfaces on the server

  1. Connect to the server via SSH or via KVM console.

  2. Open the netplan utility configuration file with the vi text editor:

    vi /etc/netplan/01-netcfg.yaml

  3. Add Q-in-Q settings for the network interface of the private network:

    ...
        vlans:
          <eth_name>.<id>:
                id: <id>
                link: <eth_name>
                mtu: 1400
                addresses:
                    - [<ip_address>/<mask>]

    Specify:

    • <eth_name> - the name of the network interface of the private network;
    • <id> - Q-in-Q tag, you can specify a number from 2 to 4094;
    • <ip_address> - IP address from the new private subnet;
    • <mask> - subnet mask.
    Example of a netplan utility configuration file
    network:
        version: 2
        renderer: networkd
        ethernets:
            eth0:
                addresses: [203.0.113.0/24]
                gateway4: 203.0.113.1
                nameservers:
                    addresses: [198.51.100.1,198.51.101.1]
            eth1:
                addresses: [192.168.0.2/24]
    ...
        vlans:
            eth1.40:
                id: 40
                link: eth1
                mtu: 1400
                addresses:
                    - [10.0.0.15/24]

  4. Press ESC.

  5. Exit the vi text editor with your changes saved:

    :wq

  6. Apply the configuration:

    netplan apply

  7. Optional: reboot the server.