Block Counter-Strike 2 server relays by country using Windows Firewall rules.
Interactive world map • Country controls • Rule verification
CS2 Relay Blocker helps you control which Counter-Strike 2 Steam Datagram Relay regions your PC can reach by managing local Windows Firewall rules. Select countries, continents, or individual server relays to block, then verify that the expected firewall rules exist.
Server data is fetched from the live Steam SDR (Steam Datagram Relay) API on startup and when you refresh, so the app can follow Valve relay changes without hardcoded server lists.
Note: This tool requires Administrator privileges to create/delete Windows Firewall rules.
Download the latest packaged build from the Releases page, or build from main if you want unreleased source changes.
Download: cs2_server_blocker.exe
SHA256:
FF872C492A5926BDB6AA1C9BE4D8BE2D6255C21CA2A7B05DD0A1A52B35948871
- Replaced ICMP ping checks with firewall rule verification. Many relays ignore ping even when game traffic is allowed, so the app now checks the actual
CS2_Block_Windows Firewall rules. - Fixed stale block state after refreshes and block/unblock operations by resyncing firewall rules after changes.
- Fixed continent-level click actions and "block all except" bookkeeping.
- Improved large operations by splitting firewall changes into bounded PowerShell batches.
- Fixed country parsing for descriptions such as
Stockholm - Swedenand U.S. state names likeGeorgia,Illinois, andWashington.
- Dot-matrix world map showing all CS2 server locations
- Green dots = active servers, Red dots = blocked servers
- Hover over any dot to see server details: name, code, IPs, and port ranges
- Click a server dot to toggle block status
- Scroll to zoom and click-drag to pan
- Servers grouped by country and continent
- Color-coded status: Red = blocked, Green = active, Orange = partially blocked
- Checkbox selection for bulk block/unblock operations
- Continent-level checkbox to select all countries at once
- Click a country or continent name to toggle its block state
- Block Selected / Unblock Selected / Unblock All buttons
- Countries with multiple servers have an expand button
- Block or unblock individual servers within a country
- See each server's description and current status
- Per-continent dropdown: block every country in a continent except one
- Automatically unblocks the excepted country if it was previously blocked
- Hidden when all countries in a continent are already blocked
- Reads Windows Firewall rules and compares them to the app's expected state
- Per-server and per-country rule status summaries
- Status indicators: "Rules OK", "Rules missing", and "Unexpected block rule"
- Search for a server/country and use Verify Listed Rules to check the visible results
- Use the Rules button next to a country to verify every server in that country
- Firewall changes are split into bounded PowerShell batches for speed and command-line reliability
- Combines relay IPs per server, creating 4 rules per server instead of per-relay
- Supports both old and new rule formats
- Resyncs firewall state after every completed block/unblock operation
- Download
cs2_server_blocker.exefrom the latest release. - Right-click the executable and choose Run as Administrator.
- If Windows SmartScreen warns because the executable is unsigned, choose More info and Run anyway only if you trust this repository/source.
Prerequisites:
- Windows 10/11
- Rust toolchain (rustup.rs)
- Administrator privileges for firewall rule management
git clone https://github.com/fpsheaven/cs2serverblocker.git
cd cs2serverblocker
cargo build --releaseThe executable will be at:
.\target\release\cs2_server_blocker.exeRun the source-built executable as Administrator:
Start-Process -FilePath ".\target\release\cs2_server_blocker.exe" -Verb RunAsOr launch it from an already elevated terminal:
.\target\release\cs2_server_blocker.exeFrom a normal VS Code PowerShell terminal, build and request elevation in one command:
cargo build --release; Start-Process -FilePath ".\target\release\cs2_server_blocker.exe" -Verb RunAsFor local UI/debug testing without firewall changes:
cargo run- Launch the app as Administrator.
- Let the app load the live Steam SDR server list and sync existing firewall rules.
- Block the countries or continents you do not want.
- Use Refresh after Steam relay changes or after updating the app.
- Use Rules on a country, or search and use Verify Listed Rules, to confirm the firewall rules match the app state.
- Start or restart CS2 after changing many regions so matchmaking sees the updated network conditions.
- Fetches server data from the Steam SDR Config API
- Groups servers by country and continent using geographic data and server descriptions
- Creates Windows Firewall rules with
netsh advfirewall firewallto block TCP/UDP traffic to selected relay IPs on their port ranges - Syncs state on startup and after changes by reading existing firewall rules with the
CS2_Block_prefix - Verifies rules by comparing expected blocked/active app state against the actual Windows Firewall rules
For each blocked server, 4 rules are created:
| Direction | Protocol | Rule Name |
|---|---|---|
| Inbound | TCP | CS2_Block_{code} |
| Inbound | UDP | CS2_Block_{code} |
| Outbound | TCP | CS2_Block_{code} |
| Outbound | UDP | CS2_Block_{code} |
All relay IPs for a server are combined into a single remoteip parameter, and port ranges are merged to cover the widest range.
Before pushing a change, run:
cargo fmt --check
cargo check
cargo test
cargo clippy --all-targets --all-features -- -D warnings
cargo build --releaseIf the release executable is already running and Windows locks target\release\cs2_server_blocker.exe, close the app first or build into a temporary target directory:
$env:CARGO_TARGET_DIR = ".build_cache\target-verify"
cargo build --releasesrc/
main.rs - Entry point, window setup, icon loading
app.rs - Main application UI and logic
api.rs - Steam SDR API client
firewall.rs - Windows Firewall rule management
map.rs - Interactive world map rendering
world_data.rs - Land mass data for map display
assets/
banner.png - README banner
icon.png - Application icon
icon.ico - Windows executable icon
build.rs - Windows resource embedding
- Rust - Systems programming language
- eframe / egui - Immediate mode GUI framework
- reqwest - HTTP client for Steam API
- serde - JSON deserialization
- image - PNG icon loading
- winres - Windows executable resource embedding
Q: Does this affect my Steam account? A: No. This tool only creates local Windows Firewall rules. It does not modify any game files or interact with your Steam account.
Q: Will I get VAC banned? A: No. This tool does not inject into or modify the game process. It only manages standard Windows Firewall rules, which is the same as manually creating rules through Windows settings.
Q: What does firewall rule verification check?
A: It reads the current CS2_Block_ Windows Firewall rules and reports whether those rules match the app's expected blocked or active state.
Q: Why did ping verification go away? A: ICMP ping is not a reliable test for CS2 relay reachability because some relays do not answer ping. Firewall rule verification is more direct for this app because it checks the rules the app actually manages.
Q: I blocked Europe except London, but CS2 still placed me in Frankfurt or Amsterdam. What should I check? A: Run the latest release as Administrator, click Refresh, then verify London, Frankfurt, and Amsterdam with Rules or Verify Listed Rules. If Frankfurt or Amsterdam shows "Rules missing", block it again. If rules are OK but matchmaking still routes there, restart CS2 and retest because matchmaking can reuse existing network/session state.
Q: Can I block specific servers within a country?
A: Yes. Click the expand button (>) next to countries with multiple servers to see and control individual servers.
Q: How do I remove all rules created by the app?
A: Run the app as Administrator and click Unblock All. The app removes rules with the CS2_Block_ prefix, including older per-IP rule names from previous builds.