diff --git a/TESTING.md b/TESTING.md
index cc60c84..fde97a4 100644
--- a/TESTING.md
+++ b/TESTING.md
@@ -103,6 +103,23 @@ where.exe link
 
 `rustc -vV` should report a `host` containing `x86_64-pc-windows-msvc`.
 
+## Local Preflight
+
+Run these before moving to the hardware test:
+
+```bash
+cargo fmt --check
+cargo test --workspace
+cargo clippy --workspace --all-targets -- -D warnings
+cargo build --release -p lanparty-relay -p lanparty-gateway
+```
+
+The workspace tests include real client/relay/gateway session coverage for
+DHCP-shaped traffic, ARP-shaped traffic, ICMPv4 ping-shaped traffic, UDP
+broadcast discovery traffic, and gateway restart lifecycle. They do not prove
+the Windows TAP driver, real LAN DHCP, physical switch MAC learning, or a real
+game. Those are the manual pass conditions below.
+
 ## Build
 
 On the relay or Linux build host: