How to fix ERROR_NETWORK_UNREACHABLE

Code:1231 (0x4CF)

Description

The network location cannot be reached.

Incorrect Network Configuration:
- Misconfigured IP address, subnet mask, or default gateway.
- Incorrect DNS server settings.
Network Connectivity Issues:
- Faulty or disconnected network cables.
- Issues with network devices such as routers, switches, or modems.
- Wireless network signal interference or weak signal strength.
Firewall or Security Software Restrictions:
- Firewall settings blocking network traffic.
- Antivirus software interfering with network connections.
Disabled or Faulty Network Adapter:
- Network adapter is disabled in the system settings.
- Outdated or corrupted network adapter drivers.
- Incompatibility between the network adapter and other hardware components.
Duplicate IP Addresses:
- Another device on the network is using the same IP address, causing an IP conflict.
Network Adapter and Switch Configuration Issues:
- Mismatched duplex levels or transfer speed settings between network adapters and switch ports.
- Autosense settings not correctly detecting network adapter speeds.
- Incompatibility between network adapters and motherboards or other hardware components.
Network Policies and Permissions:
- Restrictions imposed by network policies in a domain or enterprise environment.
- Insufficient permissions to access network resources.
Hardware Failures:
- Malfunctioning network adapter or port.
- Failing network hardware components.

Check Network Cables:
- Ensure all Ethernet cables are securely connected.
- Replace any damaged or worn-out cables.
- Swap Cables: Try using a different network cable between the failing system and the hub or switch to rule out cable issues.
Check Network Devices:
- Restart routers, switches, or modems.
- Ensure that network devices are powered on and functioning properly.

Enable Network Adapter:
- Go to Control Panel > Network and Sharing Center > Change adapter settings.
- Right-click on the network adapter and select Enable if it is disabled.
Update Network Adapter Drivers:
- Open Device Manager (press Win + X and select Device Manager).
- Expand Network adapters, right-click on your adapter, and select Update driver.
- Choose Search automatically for updated driver software.
Replace Faulty Network Adapter:
- If the network adapter is suspected to be incompatible or faulty, replace it with a network adapter that has been tested and proven reliable.

Check IP Settings:
- Open Command Prompt and type ipconfig /all to view current network settings.
- Ensure that the IP address, subnet mask, default gateway, and DNS servers are correctly configured.
Renew IP Address:
- In Command Prompt, run:
  - ipconfig /release
  - ipconfig /renew
Reset Network Settings:
- Run netsh int ip reset and netsh winsock reset in Command Prompt as administrator.
- Restart your computer after executing the commands.

Match Duplex and Speed Settings:
- Ensure that both the network adapter and the switch port are set to the same duplex mode (full-duplex or half-duplex) and speed (10 Mbps, 100 Mbps, or 1 Gbps).
  - Network Adapter Settings:
    - Go to Device Manager > Network Adapters > Right-click your adapter > Properties > Advanced tab.
    - Adjust the Speed & Duplex setting to match the switch port.
  - Switch Port Settings:
    - Access the switch's management interface to verify and adjust port settings.
Disable Autosensing if Necessary:
- Autosense settings may not correctly detect the speed of some network adapters.
- Manually set the network adapter and switch port to the desired speed and duplex settings.
Test with Lower Settings:
- Manually Set to Half-Duplex and Lower Speed:
  - Temporarily set the network adapter to half-duplex and 10 Mbps to see if the connection can be established at a lower transmission speed.
  - Connect the system to a switch configured to half-duplex and 10 Mbps, or use a 10 Mbps hub.
- Increase Performance Gradually:
  - Increase the speed settings manually to 100 Mbps, and then restart the computer.
  - Test for network connectivity loss, then increase the setting to full-duplex, and restart again.
  - If network loss occurs, reduce the duplex setting and speed to the previous stable settings.

Windows Firewall:
- Go to Control Panel > Windows Defender Firewall > Turn Windows Defender Firewall on or off.
- Temporarily disable the firewall to test connectivity.
Antivirus Software:
- Temporarily disable antivirus software to see if it is blocking network access.
- Note: Re-enable security software after testing to maintain system protection.

Check for Duplicate IP Addresses:
- Ensure that no other device on the network is using the same IP address.
- Assign a static IP address outside the DHCP range to avoid conflicts.

Network Permissions:
- Ensure you have the necessary permissions to access network resources.
- Contact your network administrator if in a domain environment.
Group Policy Settings:
- Run gpupdate /force in Command Prompt to update group policies.

Full System Scan:
- Use reputable antivirus software to perform a comprehensive scan.
- Remove or quarantine any detected threats.

Update Router/Switch Firmware:
- Check the manufacturer's website for firmware updates.
- Follow the instructions carefully when updating firmware.
Windows Updates:
- Go to Settings > Update & Security > Windows Update.
- Click Check for updates and install any available updates.

Network Hardware:
- Replace malfunctioning routers, switches, or network adapters.
- Test with known-good hardware to isolate the issue.