1
Diagnostic step 1
Enable detailed logging in the VPN client to capture route installation events around suspend/resume and compare logs from a successful cold connect and a failed resume connect.
FULL AI ANALYSIS
Corporate VPN loses route to internal subnets after Windows 10 resume from sleep (no errors shown)
Generated Oct 3, 2026, 12:35:03 AM
Analysis summary
The client maintains the virtual adapter and an IP address after resume but lacks the server-pushed routes, suggesting the VPN control plane kept the tunnel but failed to re-run route installation steps after the host network re-initialized. Possible triggers include race conditions on resume where the VPN client assumes interface state unchanged, power-management causing adapter reinitialization, or privilege/context changes preventing route modification.
Possible causes
VPN client does not reapply server-pushed routes after underlying Wi‑Fi adapter reinitialization post-resume due to race conditions or missing resume hooks.
75%TAP/TUN virtual adapter is re-created with a different interface index on resume, and the VPN client fails to bind route operations to the new index.
70%Third-party security/endpoint agent is reverting route table changes on resume for policy enforcement.
35%Windows networking stack blocks non-elevated route changes after resume; VPN client may have lost elevated privileges and cannot program routes.
15%Suggested fixes
2
Diagnostic step 2
On resume, run 'route print' and 'netsh interface ipv4 show interfaces' from an elevated prompt to check if interface index or names changed; if index changed, confirm if the VPN client uses interface indexes.
3
Diagnostic step 3
Temporarily create a small elevated resume script that calls 'netsh interface ipv4 add route' for a pushed route to test whether manual route addition succeeds post-resume; this verifies elevation/permissions are not the blocker.
4
Diagnostic step 4
Disable or temporarily uninstall endpoint security/agent to rule out policy interference (do this only with IT approval and outside of production access to corporate resources).
5
Diagnostic step 5
If diagnostics indicate a client bug (client doesn't reapply routes), work with corporate IT to update the client or add a resume-triggered reconnect as an approved workaround; escalate to VPN vendor/IT if logs point to client internal failure.