Understanding Interface Metrics
Windows uses a routing table to determine which network interface handles outgoing traffic. Each interface has an associated "metric" value, which acts as a cost indicator. The system selects the path with the lowest metric value as the default route. When multiple adapters are active, such as Ethernet and Wi-Fi, Windows automatically assigns metrics based on link speed and type. Typically, wired connections receive lower (better) metrics than wireless ones because they are faster and more stable. However, this automatic assignment may not always align with your specific needs, especially if you require simultaneous connectivity for different purposes.
Accessing Advanced Network Settings
The first step involves navigating to the control panel where network adapters are managed. Press Win + R to open the Run dialog, type ncpa.cpl, and press Enter. This command opens the Network Connections window directly. Here, you will see all available network adapters, including Wi-Fi, Ethernet, Bluetooth networking, and virtual adapters. Identify the two connections you wish to prioritize, typically labeled as "Wi-Fi" and "Ethernet" or similar names indicating the physical hardware.
Navigating to IP Properties
Right-click on the first adapter you want to configure and select Properties. In the list of items, locate and double-click on Internet Protocol Version 4 (TCP/IPv4). If you are using IPv6 exclusively, select Internet Protocol Version 6 (TCP/IPv6) instead. Most users operate on IPv4, so ensure you are modifying the correct protocol version. Clicking this item opens the property sheet for that specific protocol instance on that adapter.
Modifying the Automatic Metric
In the TCP/IPv4 Properties window, click the Advanced... button located at the bottom right. A new window titled "Advanced TCP/IP Settings" will appear. Navigate to the IP Settings tab. You will see a section labeled "Automatic metric". By default, this option is selected, allowing Windows to calculate the metric dynamically. To override this behavior, deselect the Automatic metric radio button. Immediately below it, a text box labeled Interface metric becomes editable.
Enter a numeric value into this box. Lower numbers indicate higher priority. For example, if you want the Ethernet connection to be the primary route for all internet traffic, assign it a low value like 10. For the Wi-Fi connection, which should remain secondary but active, assign a higher value, such as 20 or 50. Ensure that the value you choose does not conflict with other static metrics you might have set elsewhere. After entering the values, click OK to close the advanced settings, then OK again to close the IPv4 properties. Repeat this process for the second adapter, ensuring its metric is higher than the primary one if it is intended to be secondary.
Verifying Route Preferences
Once the changes are applied, verify that Windows has updated the routing table correctly. Open Command Prompt by searching for cmd in the Start menu. Type the following command and press Enter:
route printThis command displays the current IPv4 routing table. Look for the Active Routes section. Find the entry for 0.0.0.0 with a mask of 0.0.0.0, which represents the default route. Check the "Metric" column next to the gateway address. It should reflect the manual value you assigned to the preferred interface. If the metric matches your expectation, the configuration is successful. If not, re-check the steps above to ensure the automatic metric was disabled.
Testing Connectivity
To confirm that traffic is flowing through the desired interface, you can use tools like tracert or check the active connections using netstat -an. Additionally, visiting a site like whatismyipaddress.com can help verify which public IP is being used, confirming that the external traffic is routed through the primary connection. Note that internal LAN resources accessible via both interfaces may still be reachable through either path depending on subnet masks and local routing rules, but general internet traffic will follow the lowest metric path.
If you encounter issues where the secondary connection drops entirely, ensure that the "Media Sense" feature is not interfering. Sometimes, disabling unused features in the adapter's advanced properties can help maintain stability. For more complex network configurations involving DNS or specific application routing, consider reviewing related troubleshooting guides.
Frequently Asked Questions
What happens if I set the same metric for both adapters?
Windows will load-balance traffic between the two interfaces using Equal-Cost Multi-Path (ECMP) routing. This means packets may alternate between the Ethernet and Wi-Fi connections randomly. This can lead to inconsistent latency or connection drops for stateful protocols like TCP, so it is generally better to keep metrics distinct unless you specifically need load balancing.
Can I change the metric for only specific applications?
No, the interface metric applies to the entire operating system's routing table, not individual applications. All traffic leaving the computer will prefer the interface with the lowest metric. To route specific apps differently, you would need to use third-party firewall software or policy-based routing tools that support per-application rules.
Does changing the metric affect local network access?
Local access depends on the subnet masks configured for each interface. If both adapters are on the same subnet, conflicts may arise. If they are on different subnets, Windows will use the most specific route (longest prefix match) for local resources. Changing the default route metric primarily affects traffic destined for outside your local networks, such as internet browsing.
How do I revert to automatic metrics?
Simply return to the Advanced TCP/IP Settings window for each adapter, re-select the Automatic metric radio button, and click OK. Windows will recalculate the optimal metric based on link speed and type immediately after applying the change.
Why is my Wi-Fi still used for some internet traffic?
If you observe mixed usage, check if any applications are binding specifically to the Wi-Fi IP address. Also, verify that no other routing rules exist in the route print output that might override the default route. Sometimes, cached DNS entries or persistent connections established before the metric change can cause temporary inconsistencies.