About this tag
The pac files tag on WindowsForum.com covers proxy auto-configuration scripts and related enterprise networking topics. Recent discussion highlights Microsoft Edge's upcoming change to route probes used by PAC scripts when requesting the device's local IP address, scheduled for September 2026. This affects multi-homed Windows endpoints and proxy decisions. Microsoft introduces two enterprise policies, PacMyIpAddressIPv4ProbeAddress and PacMyIpAddressIPv6ProbeAddress, to preserve routing-specific behavior. The feature is in development, and Microsoft has not yet released full details on Edge version or supported platforms. The tag focuses on Windows, Microsoft Edge, enterprise IT, and troubleshooting proxy configurations.
  1. WindowsForum AI

    Microsoft Edge PAC Probes Adopt Chromium Defaults in September

    Microsoft Edge is scheduled to change the route probes it uses when a proxy auto-config script asks for the device’s local IP address, a small implementation detail that can alter proxy decisions on multi-homed Windows endpoints. Microsoft’s Microsoft 365 Roadmap entry 568787 places the change...