Restore Ubuntu Network Configuration → DHCP
Recover WiFi from static IP issues — back to stable automatic DHCP mode
🔴 Recommended when: static IP configuration causes instability
- ⚠️ WiFi fails during boot
- ⚠️ "Activation of network connection failed"
- ⚠️ IP configuration could not be reserved
- ⚠️ DHCP previously worked normally
- ⚠️ Static IP caused random disconnects
1
Check Existing Network Connections
Open a terminal and list all saved connections:
nmcli connection show
📡 Example output:
NAME UUID TYPE DEVICE
MyWifi xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx wifi wlp1s0b1
NAME UUID TYPE DEVICE
MyWifi xxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx wifi wlp1s0b1
📍 Take note of your WiFi connection name — e.g., MyWifi. You will need it in next commands.
2
Switch to DHCP (auto)
Replace "MyWifi" with your actual connection name and run:
nmcli connection modify "MyWifi" ipv4.method auto✅ This forces IPv4 configuration back to Automatic DHCP.
3
Remove Old Static IP Settings
Clear any leftover static IP, gateway, and DNS entries:
nmcli connection modify "MyWifi" ipv4.addresses ""nmcli connection modify "MyWifi" ipv4.gateway ""nmcli connection modify "MyWifi" ipv4.dns ""
💡 Note: Replace "MyWifi" with your connection name. Empty strings fully erase previous static config.
4
Restart NetworkManager
Apply changes by restarting the networking service:
sudo systemctl restart NetworkManager⏳ Wait 10–15 seconds for the service to fully reload.
5
Disconnect & Reconnect WiFi
Refresh the connection manually:
nmcli connection down "MyWifi"nmcli connection up "MyWifi"
6
⚠️ If Connection Still Fails
If DHCP still doesn't work, delete the corrupted WiFi profile entirely:
nmcli connection delete "MyWifi"Then restart NetworkManager again:
sudo systemctl restart NetworkManagerNow reconnect from the Ubuntu GUI: click WiFi icon → select your SSID → enter password.
🔴 IMPORTANT: Do not configure static IP. Leave IPv4 Method = Automatic (DHCP).
🔴 IMPORTANT: Do not configure static IP. Leave IPv4 Method = Automatic (DHCP).
7
Verify DHCP IP Address
Check your interface gets an IP from DHCP:
ip addr
💻 Look for your WiFi interface (e.g., wlp1s0b1).
You should see something like: inet 192.168.1.25/24 (dynamic range).
You should see something like: inet 192.168.1.25/24 (dynamic range).
8
Verify Default Gateway
Confirm the routing table shows a correct default route:
ip route
✅ Expected output: default via 192.168.1.1 dev wlp1s0b1 (your router IP)
9
Test Internet Connectivity
Ping a domain to validate DNS + internet access:
ping google.com
🟢 You should see 64 bytes from ... replies. Press Ctrl+C to stop.
10
Recommended Next Step
After DHCP is stable, prefer hostname-based access instead of static IP:
- Use server-hp.local or hostname.local for reliable access.
- Avoid manual static IP assignments to prevent future NetworkManager conflicts.
🚀 Benefits: stable boot networking · automatic IP management · fewer connectivity failures.
🔧 Optional Cleanup (Highly Recommended)
Disable WiFi power saving — improves stability on Ubuntu laptops & avoids random disconnects.
Create NetworkManager config file:
sudo nano /etc/NetworkManager/conf.d/wifi-powersave.confAdd the following lines:
[connection]wifi.powersave = 2
Save file (Ctrl+O, then Ctrl+X) and restart NetworkManager:
sudo systemctl restart NetworkManager
✅ This setting completely disables Wi-Fi powersave, often resolving roaming delays and dropouts.
🔁 DHCP mode = ✨ automatic addresses
⚠️ Never set static IPv4 on this connection
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