VirtualBox中Ubuntu虚拟机无法联网，需同时实现宿主机与虚拟机互通

Hey there, let's get your Ubuntu Server VM connected to the internet while keeping that host-VM connectivity you already have. Since you're using bridge mode and the host-VM link works, we just need to adjust a few network settings on the VM side. Here's how to fix it step by step:

You mentioned enp0s3 is the working interface (with eth0 being unused), so first let's make sure it's enabled:

• Run ifconfig -a or ip link show to confirm enp0s3 is listed.
• If it's not marked as "UP", enable it with:

  sudo ip link set enp0s3 up
  

Since you're using bridge mode, your VM should sit on the same network segment as your Windows 7 host's WiFi connection. Let's start with the simplest option first:

Option A: Use DHCP (Auto-IP Assignment) #

Most home routers support DHCP, which will automatically assign your VM a valid IP, gateway, and DNS:

• Run this command to request an IP from your router:

  sudo dhclient enp0s3
  

• Check if it worked by running ip addr show enp0s3 — you should see an IP in the same range as your host's WiFi (e.g., if your host is 192.168.1.5, the VM might get 192.168.1.10).

Option B: Manual Static IP (If DHCP Fails) #

If DHCP doesn't work, set a static IP that matches your host's network:

1. Get your host's network details: On Windows 7, open Command Prompt and run ipconfig. Look for your WiFi adapter's:

   • IPv4 Address (e.g., 192.168.1.5)
   • Subnet Mask (e.g., 255.255.255.0)
   • Default Gateway (e.g., 192.168.1.1)
   • DNS Servers (you can also use public ones like 8.8.8.8 or 1.1.1.1)

2. Configure the VM's network:

   • For Ubuntu 18.04+ (uses Netplan):
     Edit the Netplan config file (usually in /etc/netplan/ — look for a .yaml file like 00-installer-config.yaml):

     network:
       ethernets:
         enp0s3:
           addresses: [192.168.1.100/24]  # Pick an unused IP in your host's network range
           gateway4: 192.168.1.1          # Your host's default gateway
           nameservers:
             addresses: [8.8.8.8, 1.1.1.1] # Public DNS or your router's DNS
       version: 2
     

     Apply the changes with:

     sudo netplan apply
     

   • For older Ubuntu versions (uses /etc/network/interfaces):
     Edit the file with:

     sudo nano /etc/network/interfaces
     

     Add these lines (replace values with your host's details):

     auto enp0s3
     iface enp0s3 inet static
         address 192.168.1.100
         netmask 255.255.255.0
         gateway 192.168.1.1
         dns-nameservers 8.8.8.8 1.1.1.1
     

     Restart the network service:

     sudo /etc/init.d/networking restart
     

Let's confirm everything works:

• First, verify host-VM connectivity is still intact: ping [your-windows-host-ip] (replace with your host's actual IP from ipconfig).
• Next, ping your router's gateway: ping 192.168.1.1 (use your gateway IP). If this works, your VM can reach the router.
• Then ping a public DNS server: ping 8.8.8.8. Success here means your VM can reach the internet.
• Finally, test DNS resolution: ping google.com. If this works, your VM can resolve domain names properly.

• Ensure bridge mode targets the right adapter: In your virtualization software (VirtualBox/VMware), double-check that bridge mode is set to your WiFi adapter (not a wired Ethernet adapter, since you're using WiFi).
• Ubuntu Firewall: Even if Windows Firewall is off, Ubuntu's default firewall (ufw) might block traffic. Temporarily disable it to test:

  sudo ufw disable
  

  If this fixes it, you can re-enable it and add rules to allow internet traffic later.
• Host WiFi is working: Confirm your Windows 7 laptop can actually connect to the internet — if the host has no internet, the VM won't either via bridge mode.

内容的提问来源于stack exchange，提问作者Albert Lazaro de Lara