sudo nmcli connection add type bridge ifname br0 con-name br0 

 sudo nmcli connection add type ethernet con-name br0-slave ifname eno1 master br0 

sudo nmcli connection modify br0 ipv4.method auto
sudo nmcli connection up br0
sudo nmcli connection up br0-slave

 nmcli connection show 

Once bridged, your host’s IP will now be assigned to br0, not eno1. This is normal: eno1 is now just a physical port slave.

Option A: Use virt-manager Open virt-manager. Edit → Connection Details → Virtual Networks tab. You can disable default NAT network (optional). When creating or editing a VM: Go to NIC → Change “Network source” to “Specify shared device name”.

Enter: br0.

Set device model to virtio (recommended for Linux guests).

✅ Check your guest interface name Inside your guest VM, run: bash CopyEdit ip a

Look for a device name like: CopyEdit ens3, ens4, enp1s0, eth0, etc.

Example output: yaml CopyEdit 2: ens3: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 …

  inet 192.168.1.50/24 ...

In this example, the interface is ens3.

✅ Configure DHCP using netplan (Ubuntu 18+) Most recent Ubuntu versions use netplan for network configuration. Edit netplan file bash CopyEdit sudo nano /etc/netplan/01-netcfg.yaml

File name might be slightly different (e.g., 00-installer-config.yaml). You can list files: bash CopyEdit ls /etc/netplan/

Example DHCP config yaml CopyEdit network:

version: 2
ethernets:
  ens3:
    dhcp4: true

Replace ens3 with your interface name, exactly as shown in ip a.

Apply changes bash CopyEdit Netplan generate sudo netplan apply

Check bash CopyEdit ip a

You should now see an IP like 192.168.1.123 on ens3.

✅ If all else fails: Try manual DHCP request If your config looks correct but no IP yet: bash CopyEdit sudo dhclient ens3

✅ Test bash CopyEdit ping 8.8.8.8

Or: bash CopyEdit ping google.com

💬 💥 Summary for Step 4 (expanded) ✅ Identify your VM interface name (e.g., ens3). ✅ Edit /etc/netplan/xxx.yaml to set dhcp4: true. ✅ Apply with sudo netplan apply. ✅ Check ip a to confirm you got a LAN IP. ✅ Test connectivity.

If dhclient enp1s0 hangs When dhclient enp1s0 hangs, that usually means: The VM is not seeing the bridge properly, or

There’s no DHCP response coming through the bridge, or

The VM's virtual NIC isn't attached to the bridge at all.

💡 Let’s troubleshoot step by step ✅ 1️⃣ Confirm guest NIC is really connected to the bridge On your host, run: bash CopyEdit virsh dumpxml <your-vm-name> | grep -A 5 '<interface'

Check that you see: xml CopyEdit <interface type='bridge'>

<source bridge='br0'/>

✅ 2️⃣ Check bridge is working on host On host, run: bash CopyEdit brctl show

(or, if brctl isn’t installed, install: sudo apt install bridge-utils) Example output: yaml CopyEdit bridge name bridge id STP enabled interfaces br0 8000.xxxxxxxxxxxx no eno1

                                                  vnet0

You should see eno1 as an interface in br0.

You should also see something like vnet0, which is your VM’s virtual NIC.

If you do not see vnet0, the VM isn’t connected properly.

✅ 3️⃣ Check if bridge is passing DHCP On your host: bash CopyEdit tcpdump -i br0 port 67 or port 68

Then, from inside guest, run: bash CopyEdit sudo dhclient enp1s0

On host, you should see DHCP discover packets. If you see nothing, the VM is not sending or packets aren’t passing.

⭐ If you'd like, please paste those outputs — I’ll walk you line by line and tell you exactly what to fix. Want to? You said: I don't see vnet0 ChatGPT said: 💥 Aha! That’s the big clue — you don’t see vnet0 in your bridge.

🔎 Why this is critical When a KVM guest is running and correctly connected to a bridge (like br0), you must see an interface like vnet0, vnet1, etc. in brctl show. If it is missing, that means: The VM’s NIC is not actually connected to the bridge.

It's still connected to the default virbr0 (NAT) or misconfigured.

✅ Fix your VM's NIC to point to br0 🟢 If using virt-manager (GUI) 1️⃣ Shut down the VM. 2️⃣ Open virt-manager. 3️⃣ Select the VM → Open → Click Show virtual hardware details (the ⚙️ icon). 4️⃣ Select the NIC entry. 5️⃣ In “Network source”: Change from “NAT” (or default) to “Bridge br0”.

If “br0” does not show, choose Specify shared device name, then type br0.

Device model: virtio (recommended for Linux).

6️⃣ Apply, then start the VM again.

🟢 If using virsh (CLI) Edit the VM bash CopyEdit sudo virsh edit <vm-name>

Find <interface> block It may look like this (incorrect example): xml CopyEdit <interface type='network'>

<source network='default'/>
...

</interface>

Change it to use bridge xml CopyEdit <interface type='bridge'>

<source bridge='br0'/>
<model type='virtio'/>

</interface>

Save and exit.

Restart the VM bash CopyEdit sudo virsh start <vm-name>

✅ Check again On the host, run: bash CopyEdit brctl show

You should now see something like: yaml CopyEdit bridge name bridge id STP enabled interfaces br0 8000.xxxxxxxxxxxx no eno1

                                                   vnet0

✅ Retry DHCP in guest Inside the guest: bash CopyEdit sudo ip link set enp1s0 up sudo dhclient enp1s0

Check: bash CopyEdit ip a

💬 Summary (your next moves) ✅ Fix the VM NIC so it points to br0. ✅ Confirm vnet0 appears in brctl show. ✅ Retry DHCP inside guest. ✅ Check guest IP.

⭐ If you'd like, paste your current <interface> XML block or a screenshot of the virt-manager NIC settings — I can write exactly what to change for you (ready to copy/paste). Want me to? You said: Hooray.. we're up ChatGPT said: 🎉👏 Fantastic!! That’s exactly what we like to hear — well done!

✅ Your VM is now on the LAN, with its own real IP. ✅ vnet0 properly shows up in the bridge. ✅ You can reach it directly from your other machines.

I have an Linux mint host and running a KVM server, which has a bridged network interface. So, now br0 has my ip address. The issue is that when my computer sleeps and wakes up, br0 doesn't have an IP address ChatGPT said: This is a common issue with Linux bridges (like br0) on laptops or desktops that sleep (suspend) and wake. When your system suspends, the physical network interface (e.g., enp3s0, eth0, etc.) is brought down, and when it resumes, NetworkManager or your network stack doesn’t always properly reinitialize the bridge (br0), so it ends up without an IP. Here’s a detailed explanation and options to fix it.

🔎 Why does it happen? When the system sleeps: The physical NIC is turned off or disconnected.

The bridge (br0) remains up but “disconnected” from the physical NIC.

On resume, the NIC may come up, but the bridge may not automatically reacquire an IP via DHCP.

✅ Solutions 1️⃣ Restart NetworkManager on resume This is often the simplest fix if you're using NetworkManager. Create a file: bash CopyEdit sudo nano /etc/systemd/system/nm-resume.service

Paste: ini CopyEdit [Unit] Description=Restart NetworkManager after resume After=suspend.target

[Service] Type=oneshot ExecStart=/usr/bin/systemctl restart NetworkManager

[Install] WantedBy=suspend.target

Then enable it: bash CopyEdit sudo systemctl enable nm-resume.service

This will restart NetworkManager whenever your system resumes, causing br0 to reacquire its IP.