diff --git a/Cargo.lock b/Cargo.lock
index f77e0bd..970506d 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -437,6 +437,12 @@ dependencies = [
  "heapless 0.6.1",
 ]
 
+[[package]]
+name = "nanorand"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "ac1378b66f7c93a1c0f8464a19bf47df8795083842e5090f4b7305973d5a22d0"
+
 [[package]]
 name = "nb"
 version = "0.1.3"
@@ -710,10 +716,11 @@ dependencies = [
 [[package]]
 name = "smoltcp-nal"
 version = "0.1.0"
-source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=7572183#757218316620e074405bc38ff5502ef17a8a3499"
+source = "git+https://github.com/quartiq/smoltcp-nal.git?rev=8468f11#8468f11abacd7aba82454e6904df19c1d1ab91bb"
 dependencies = [
  "embedded-nal",
  "heapless 0.6.1",
+ "nanorand",
  "smoltcp",
 ]
 
diff --git a/Cargo.toml b/Cargo.toml
index 0c4ab0d..f4db4d8 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -60,7 +60,7 @@ rev = "314fa5587d"
 
 [dependencies.smoltcp-nal]
 git = "https://github.com/quartiq/smoltcp-nal.git"
-rev = "7572183"
+rev = "8468f11"
 
 [patch.crates-io.minimq]
 git = "https://github.com/quartiq/minimq.git"
diff --git a/hitl/run.sh b/hitl/run.sh
index 0203071..40f9039 100755
--- a/hitl/run.sh
+++ b/hitl/run.sh
@@ -17,6 +17,9 @@ python3 -m pip install -r requirements.txt
 
 cargo flash --elf target/thumbv7em-none-eabihf/release/dual-iir --chip STM32H743ZITx
 
+# Before attempting to ping the device, sleep to allow Stabilizer to boot.
+sleep 30
+
 # Test pinging Stabilizer. This exercises that:
 # * DHCP is functional and an IP has been acquired
 # * Stabilizer's network is functioning as intended
diff --git a/src/hardware/configuration.rs b/src/hardware/configuration.rs
index f6f1a3b..630fe12 100644
--- a/src/hardware/configuration.rs
+++ b/src/hardware/configuration.rs
@@ -599,13 +599,25 @@ pub fn setup(
             )
         };
 
+        let random_seed = {
+            let mut rng =
+                device.RNG.constrain(ccdr.peripheral.RNG, &ccdr.clocks);
+            let mut data = [0u8; 4];
+            rng.fill(&mut data).unwrap();
+            data
+        };
+
+        let mut stack = smoltcp_nal::NetworkStack::new(
+            interface,
+            sockets,
+            &handles,
+            Some(dhcp_client),
+        );
+
+        stack.seed_random_port(&random_seed);
+
         NetworkDevices {
-            stack: smoltcp_nal::NetworkStack::new(
-                interface,
-                sockets,
-                &handles,
-                Some(dhcp_client),
-            ),
+            stack,
             phy: lan8742a,
             mac_address: mac_addr,
         }