Ubuntu 17.10下通过Netplan修改网卡IP、MAC及名称求助

Hey Zoltan, sorry to hear you’ve been grinding on this for hours—YAML’s indentation quirks and network config gotchas are no joke. Let’s walk through a reliable, step-by-step setup that should stick after reboot. We’ll focus on Netplan (common on Ubuntu 18.04+) since you mentioned YAML files, but I’ll throw in notes for other distros too.

1. First, Identify Your Current Network Hardware #

Before writing any config, let’s get clear on what we’re working with. Run these commands in your terminal:

• ip link show: Lists all network interfaces. Note the current name (like enp0s3) and its original MAC address (looks like aa:bb:cc:dd:ee:ff).
• ip route show: Find your default gateway (usually something like 192.168.1.1).
• cat /etc/resolv.conf: Grab your DNS servers (e.g., 8.8.8.8 or your router’s IP).

2. Write a Valid Netplan YAML Config #

Netplan lives in /etc/netplan/—you’ll probably have a file like 00-installer-config.yaml or 01-netcfg.yaml. Replace its contents with this template, adjusting the values to match your network:

network:
  version: 2
  ethernets:
    # We'll use the original MAC to target the interface (avoids name changes)
    enp0s3:  # You can keep this, or use a custom name later
      match:
        macaddress: aa:bb:cc:dd:ee:ff  # Original MAC from ip link show
      set-name: my-custom-nic  # Your desired persistent interface name
      addresses:
        - 192.168.1.100/24  # Static IP + subnet mask (e.g., /24 = 255.255.255.0)
      gateway4: 192.168.1.1  # Your default gateway
      nameservers:
        addresses: [8.8.8.8, 1.1.1.1]  # DNS servers
      macaddress: aa:bb:cc:dd:ee:ff  # Your custom MAC address (must be unique on the network!)

Critical YAML Rules to Avoid Failures: #

• Use 2 spaces for indentation—tabs will break the config.
• Don’t add extra spaces after colons (e.g., macaddress: aa:bb:cc is good; macaddress : aa:bb:cc is bad).
• Make sure the custom MAC is valid (6 pairs of hex digits, no duplicates on your local network).

3. Lock in the Persistent Interface Name (Udev Rule) #

Even with Netplan’s set-name, sometimes the system reverts to random names on reboot. To fix this, create a udev rule:

1. Create a file: sudo nano /etc/udev/rules.d/70-persistent-net.rules
2. Add this line, replacing the values with your hardware info:

   SUBSYSTEM=="net", ACTION=="add", ATTR{address}=="aa:bb:cc:dd:ee:ff", NAME="my-custom-nic"
   

   • ATTR{address}: The original MAC of your network card (not the custom one you’re setting).
   • NAME: Your desired permanent interface name.

4. Apply the Config and Test #

Run these commands to activate your changes without rebooting first:

• sudo netplan generate: Checks for YAML syntax errors (if this fails, fix the indentation/typos first!).
• sudo netplan apply: Applies the config immediately.
• Verify with ip link show and ip a: Check that the interface name, MAC, and static IP are all correct.

5. Reboot and Confirm #

Finally, reboot your system with sudo reboot, then re-run ip link show and ip a to make sure everything sticks. If it still doesn’t work:

• Check /var/log/syslog for Netplan/udev errors (look for lines with netplan or udev).
• Make sure your router allows static IPs (some require reserving the IP in the router’s admin panel).
• If you’re on a non-Ubuntu distro (like CentOS/RHEL), you’ll use NetworkManager instead—just let me know and I can walk you through that setup.

内容的提问来源于stack exchange，提问作者Zoltan Szecsei