Can I connect my VPS to my other servers through a private VLAN?

Yes. Your VPS then gets an extra network card on that VLAN. That way you connect it to your dedicated servers, your colocation or your other VPSes. You arrange it through support.

What do you use it for?

Traffic between your own servers then goes over its own network, separate from your public IP addresses. Think of a web server on your VPS talking to a database server, or backups to another server.

Request

1. Open a ticket.
2. Say which services you want to connect: which VPSes, dedicated servers or colocation.
3. Support sets up the VLAN and lets you know when it's ready.

Want to know what it costs? Ask sales.

Setting it up on your VPS

On your VPS you give the new network card, for example eth1, an address from your own private range. On Linux, for example:

ip addr add 10.0.0.2/24 dev eth1
ip link set eth1 up

Use the name of your own network card and your own private address. ip link shows which network cards your VPS has. These commands work until the next reboot; then add the address to your network configuration, for example netplan or /etc/network/interfaces.

The other side

How to set up the VLAN on a dedicated server is in Can I connect my servers through a private VLAN? Are your servers in different data centres? See setting up VLANs between data centres.

See also the network options that are available.