Networking
QuantaBox gives each VM one or more virtual network adapters. This chapter explains the four network modes, the available NIC models, and how SSH port forwarding works.
Network Modes #
Each adapter operates in one of four modes, set per adapter in Settings > Network:
| Mode | Guest can reach | Reachable from | Typical use |
|---|---|---|---|
| NAT | The internet and host services, via the host's IP | The host (via port forwarding) | Default. Simple outbound internet for the guest. |
| Bridged | The internet and the LAN directly, with its own LAN IP | Anything on the LAN | The guest should appear as a real machine on your network. |
| Host-Only | The host and other host-only VMs | The host and those VMs | Isolated lab network between host and VMs, no internet. |
| Internal | Other VMs on the same internal network only | Only those VMs | Fully isolated VM-to-VM network, no host or internet. |
NAT (default)
In NAT mode the guest sits behind the host, sharing the host's connection. Outbound traffic works automatically. Inbound access requires port forwarding (see SSH Port Forwarding). The default NAT network uses:
Subnet : 10.0.2.0/24
Gateway: 10.0.2.2
DHCP : 10.0.2.15 – 10.0.2.254
DNS : 10.0.2.3Host-Only
Host-only mode creates a private network shared by the host and host-only VMs, with no internet path. The default host-only network uses:
Subnet : 192.168.56.0/24
Gateway: 192.168.56.1
DHCP : 192.168.56.100 – 192.168.56.254NIC Models #
The adapter model is the virtual network card the guest sees:
| Model | Notes |
|---|---|
| VirtIO-net | Recommended. Paravirtualized, highest performance. Native on modern Linux; Windows needs the virtio-net driver. |
| Intel PRO/1000 (e1000) | Widely supported emulated gigabit NIC. Good compatibility for installers. |
| RTL8139 | Legacy emulated NIC for very old guests. |
MAC Addresses #
Each adapter has a MAC address. QuantaBox generates one automatically, a locally-administered, unicast address, when you create the adapter. You can set a specific MAC in Settings > Network if your environment expects a fixed address (for example, DHCP reservations).
SSH Port Forwarding #
For NAT-mode guests, QuantaBox can forward a host port to the guest's SSH port (22) so you can connect to the VM over SSH from the host. When a forward is configured, QuantaBox adds a rule equivalent to:
hostfwd=tcp::<host_port>-:22The forward binds to 127.0.0.1 only, so the guest's SSH is reachable from the host but not exposed to your wider network. Once the VM is running, the SSH tab shows a ready-to-use command and downloadable connection files. See Console and Remote Access.
Choosing a Mode #
- Just need the guest online? Use NAT (the default).
- Need to reach the guest from other machines on your LAN? Use Bridged.
- Building an isolated multi-VM lab that still talks to the host? Use Host-Only.
- Need VMs to talk only to each other, fully sealed off? Use Internal.
Multiple Adapters #
A VM can have several adapters, each in its own mode. For example, one NAT adapter for internet access and one host-only adapter for a private management network. Add and configure each in Settings > Network.
Next #
Continue to Snapshots to learn how to capture and roll back VM state.