diff --git a/CHANGELOG.md b/CHANGELOG.md
index 19bf06d7..10b1b71b 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [Unreleased]
+
+### Changed
+* Network stack is randomly seeded on startup so that random ports are used.
+
 ## [0.5.0] - 03-07-2023
 
 ### Added
diff --git a/Cargo.lock b/Cargo.lock
index 11cd1276..6fd52a82 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -150,6 +150,7 @@ dependencies = [
  "minireq",
  "mono-clock",
  "panic-persist",
+ "rand_core",
  "rtt-logger",
  "rtt-target",
  "serde",
@@ -1310,9 +1311,9 @@ dependencies = [
 
 [[package]]
 name = "smoltcp"
-version = "0.9.1"
+version = "0.10.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e9786ac45091b96f946693e05bfa4d8ca93e2d3341237d97a380107a6b38dea"
+checksum = "8d2e3a36ac8fea7b94e666dfa3871063d6e0a5c9d5d4fec9a1a6b7b6760f0229"
 dependencies = [
  "bitflags 1.3.2",
  "byteorder",
@@ -1323,9 +1324,9 @@ dependencies = [
 
 [[package]]
 name = "smoltcp-nal"
-version = "0.3.0"
+version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "821854501c550f1d347b5ae469d8e273d21371ad2eb270a8ff6f37ca9a23f8bd"
+checksum = "75077a28569d93c2eed77164fd36dd224a9efcf6ecf0e574f293ed638783b000"
 dependencies = [
  "embedded-nal 0.7.0",
  "embedded-time",
diff --git a/Cargo.toml b/Cargo.toml
index 3aac8445..bea65ee9 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -28,6 +28,7 @@ exclude = [
 cortex-m = "0.7.7"
 cortex-m-rt = "0.7"
 cortex-m-rtic = "1.1"
+rand_core = "0.6"
 mono-clock = "0.1"
 systick-monotonic = "1.0.1"
 cortex-m-log = { version = "0.8.0", features = ["log-integration"] }
@@ -53,7 +54,7 @@ minireq = "0.2"
 rtt-target = {version = "0.3", features=["cortex-m"]}
 enum-iterator = { version = "1.4", default-features = false }
 enc424j600 = { version = "0.3", features = ["cortex-m-cpu"] }
-smoltcp-nal = { version = "0.3", features=["shared-stack"] }
+smoltcp-nal = { version = "0.4", features=["shared-stack"] }
 
 [build-dependencies]
 built = { version = "0.6", features = ["git2"], default-features = false }
diff --git a/src/hardware/net_interface.rs b/src/hardware/net_interface.rs
index d05aa07b..7f2eeb76 100644
--- a/src/hardware/net_interface.rs
+++ b/src/hardware/net_interface.rs
@@ -50,9 +50,11 @@ impl TcpSocketStorage {
 /// # Args
 /// * `mac` - The smoltcp interface MAC.
 /// * `settings` - The device settings to use.
+/// * `random_seed` - A random seed for the network stack.
 pub fn setup(
     device: &mut Mac,
     settings: &BoosterSettings,
+    random_seed: u64,
 ) -> (
     smoltcp::iface::Interface,
     smoltcp::iface::SocketSet<'static>,
@@ -61,12 +63,12 @@ pub fn setup(
 
     let ip_address = settings.ip_address();
 
-    let mut config = smoltcp::iface::Config::default();
-    config
-        .hardware_addr
-        .replace(smoltcp::wire::HardwareAddress::Ethernet(settings.mac()));
+    let mut config =
+        smoltcp::iface::Config::new(smoltcp::wire::HardwareAddress::Ethernet(settings.mac()));
+    config.random_seed = random_seed;
 
-    let mut interface = smoltcp::iface::Interface::new(config, device);
+    let mut interface =
+        smoltcp::iface::Interface::new(config, device, smoltcp::time::Instant::ZERO);
 
     interface
         .routes_mut()
diff --git a/src/hardware/setup.rs b/src/hardware/setup.rs
index 1cb09298..ed8ad3db 100644
--- a/src/hardware/setup.rs
+++ b/src/hardware/setup.rs
@@ -20,6 +20,7 @@ use core::convert::TryInto;
 use core::fmt::Write;
 use hal::prelude::*;
 use heapless::String;
+use rand_core::RngCore;
 use usb_device::prelude::*;
 
 /// Macro for genering an RfChannelPins structure.
@@ -377,8 +378,14 @@ pub fn setup(
         ApplicationMetadata::new(hardware_version, phy_string)
     };
 
-    let (interface, sockets) = net_interface::setup(&mut mac, &settings);
-    let network_stack = smoltcp_nal::NetworkStack::new(interface, mac, sockets, clock);
+    let mut rng = device.RNG.constrain(&clocks);
+
+    let (interface, sockets) = net_interface::setup(&mut mac, &settings, rng.next_u64());
+    let mut network_stack = smoltcp_nal::NetworkStack::new(interface, mac, sockets, clock);
+
+    let mut seed_bytes = [0; 8];
+    rng.fill_bytes(&mut seed_bytes);
+    network_stack.seed_random_port(&seed_bytes);
 
     let mut fans = {
         let main_board_leds = {