HVCI and Memory Integrity on a Windows VPS: Measuring the Performance Cost on Older vCPUs

Memory Integrity, the user-facing switch for Hypervisor-Enforced Code Integrity, moves kernel-mode code-integrity checks into a virtual trust level that the guest kernel cannot write to. On a VPS nested inside a hypervisor, that means a second layer of translation and a measurable penalty on older CPUs without the right extent-table features. This article measures the … Read more

IIS Case-Insensitive URL Collisions: Debugging Duplicate Content and Rewrite Loops

IIS routes URLs through NTFS, and NTFS treats /Products and /products as the same file. That is convenient on a case-insensitive filesystem and a source of subtle bugs when URL rewrite rules, canonical-host redirects, and application routes are written with case-sensitive assumptions copied from Linux. The result is often a rewrite loop that returns 500.19 … Read more

AppLocker vs WDAC: Choosing Application Control on Windows Server

Two built-in Windows features restrict what software may run: AppLocker and Windows Defender Application Control (WDAC, formerly Device Guard Code Integrity). They overlap enough that teams pick the wrong one and then fight it. AppLocker is policy-through-Group-Policy and readable by anyone who understands file paths and publishers. WDAC is kernel-enforced code integrity with a signed … Read more

Windows Server Failover Clustering on Two VPS Nodes: Quorum and Storage Options

A two-node Windows Server Failover Cluster is achievable on VPS infrastructure, but the constraints are different from a datacenter build. Shared storage usually does not exist, quorum is a design decision rather than an afterthought, and network latency between nodes sets the practical ceiling for what can fail over cleanly. This is the design reference … Read more

A Field Guide to netsh, Get-NetTCPConnection, and Test-NetConnection for VPS Network Troubleshooting

Network faults on a Windows VPS usually show up as a single symptom — “the app can’t connect” — while the cause sits somewhere between DNS, the firewall, the listener, and the provider’s edge. Three tools cover most of that ground: Test-NetConnection for end-to-end reachability, Get-NetTCPConnection for local listener state, and netsh for the lower-level … Read more

IIS Client Certificate Authentication (mTLS): Require, Map, and Debug 403.7 / 403.16 Errors

IIS client certificate authentication — mutual TLS, or mTLS — lets you authenticate users and services with certificates instead of, or in front of, Windows credentials. It is the strongest access control IIS offers without a VPN, and it fails in three confusing ways: 403.16 when the server rejects the client certificate chain, 403.7 when … Read more

Enabling HTTP/2 and HTTP/3 (QUIC) on IIS in Windows Server: Registry, Ciphers, and Verification

HTTP/2 is enabled by default on Windows Server 2016 and later, but HTTP/3 is not, and both need specific registry keys to behave correctly behind a proxy or load balancer. This guide covers enabling HTTP/3 over QUIC on IIS, verifying HTTP/2 is actually negotiating, and the TLS cipher suites that must be present for either … Read more