Configure and verify the proxy inside the WSL Linux process making the request. Windows proxy settings, Linux environment variables, and access to a proxy running on the Windows host are separate layers. Determine the networking mode before assuming that localhost reaches the Windows service.<\/p>\n
Reviewed and locally tested: October 12, 2026.<\/strong> Version and route observations below describe the stated test environment. A working local route does not establish a provider’s public exit, country, anonymity, speed, or uptime.<\/p>\n The commands inspect versions and distribution identity; replace the distribution name with your actual target. Our tested environment was WSL 2.7.10.0, Ubuntu 24.04, Linux Python 3.12.3 and curl 8.5.0. A different installed distribution can have another client version and environment. No WSL configuration or global proxy setting was changed for these tests. See WSL basic commands<\/a>.<\/p>\n Run the command in the intended Linux shell with PROXY_URL and CHECK_URL supplied securely. Use lowercase http_proxy for Linux curl. The example bypasses local destinations deliberately; a local diagnostic will therefore stay direct unless you change that rule for the specific test. Keep previous environment values available for restoration instead of appending permanent exports during initial troubleshooting.<\/p>\n A Windows environment variable is not evidence that a Linux child received an equivalent value. Check the configuration inside the process you are testing, and avoid printing the full environment because proxy URLs can contain credentials. Compare the environment guide<\/a> when Windows and Linux results differ.<\/p>\n In default NAT networking, a service on the Windows host may require the host address visible from Linux. Microsoft’s WSL networking guide<\/a> describes obtaining that address from the Linux default route, while mirrored networking changes localhost interoperability. Mirrored mode and automatic proxy inheritance have Windows and WSL prerequisites; check the current documentation and your configuration before relying on them.<\/p>\n Inspect the gateway for the NAT case, confirm where the Windows proxy is listening, and check the relevant firewall rule. A listener bound only to Windows loopback may not be reachable using another interface. Changing it to listen broadly is a separate exposure decision, so keep the binding and access policy narrow. The gateway is a routing address, not a fixed value to copy between computers.<\/p>\nRecord the distribution and Linux client first<\/h2>\n
wsl --version\nwsl --list --verbose\nwsl -d Ubuntu-24.04 -- curl --version<\/code><\/pre>\nSet a narrow environment for a Linux request<\/h2>\n
http_proxy="$PROXY_URL" https_proxy="$PROXY_URL" \\\nNO_PROXY="localhost,127.0.0.1" \\\ncurl --silent --show-error --fail --max-time 8 "$CHECK_URL"<\/code><\/pre>\nReach a Windows-host proxy according to the network mode<\/h2>\n
ip route show default<\/code><\/pre>\n