diff --git a/final/Cargo.toml b/final/Cargo.toml
index 902f222..42a7a02 100644
--- a/final/Cargo.toml
+++ b/final/Cargo.toml
@@ -19,6 +19,7 @@ log = "0.4.27"
 
 embassy-net = { version = "0.7.0", features = [
   "dhcpv4",
+  "proto-ipv6",
   "log",
   "medium-ethernet",
   "tcp",
@@ -57,6 +58,7 @@ smoltcp = { version = "0.12.0", default-features = false, features = [
   "proto-dhcpv4",
   "proto-dns",
   "proto-ipv4",
+  "proto-ipv6",
   "socket-dns",
   "socket-icmp",
   "socket-raw",
diff --git a/final/build.rs b/final/build.rs
index 09afabe..8005431 100644
--- a/final/build.rs
+++ b/final/build.rs
@@ -5,6 +5,7 @@ fn main() {
         println!("cargo:rerun-if-changed={}", dotenv_path.display());
     }
 
+    // Pass WIFI credentials into firmware
     if let Ok(ssid) = std::env::var("SSID") {
         println!("cargo:rustc-env=SSID={}", ssid);
     }
@@ -12,8 +13,16 @@ fn main() {
         println!("cargo:rustc-env=PASSWORD={}", password);
     }
 
+    // Export BROKER_IP and PORT as string envs also (optional, for debugging)
+    if let Ok(ip) = std::env::var("BROKER_IP") {
+        println!("cargo:rustc-env=BROKER_IP={}", ip);
+    }
+    if let Ok(port) = std::env::var("BROKER_PORT") {
+        println!("cargo:rustc-env=BROKER_PORT={}", port);
+    }
+
     linker_be_nice();
-    // make sure linkall.x is the last linker script (otherwise might cause problems with flip-link)
+    // make sure linkall.x is the last linker script
     println!("cargo:rustc-link-arg=-Tlinkall.x");
 }
 
diff --git a/final/src/mqtt/client.rs b/final/src/mqtt/client.rs
index f53ee34..1e0d966 100644
--- a/final/src/mqtt/client.rs
+++ b/final/src/mqtt/client.rs
@@ -1,5 +1,5 @@
 // src/mqtt/client.rs
-use embassy_net::{tcp::TcpSocket, Ipv4Address, Stack};
+use embassy_net::{tcp::TcpSocket, Stack};
 use embassy_time::{Duration, Timer};
 use log::info;
 use rust_mqtt::client::client::MqttClient;
@@ -8,6 +8,8 @@ use rust_mqtt::packet::v5::publish_packet::QualityOfService;
 use rust_mqtt::utils::rng_generator::CountingRng;
 use static_cell::ConstStaticCell;
 
+use crate::mqtt::config::mqtt_broker_endpoint;
+
 // TCP socket buffers (for embassy-net TcpSocket)
 static TCP_RX_BUFFER: ConstStaticCell<[u8; 2048]> = ConstStaticCell::new([0; 2048]);
 static TCP_TX_BUFFER: ConstStaticCell<[u8; 2048]> = ConstStaticCell::new([0; 2048]);
@@ -20,18 +22,11 @@ static MQTT_RX_BUF: ConstStaticCell<[u8; 1024]> = ConstStaticCell::new([0; 1024]
 pub async fn mqtt_task(stack: Stack<'static>) {
     info!("MQTT task starting...");
 
-    // Safely take buffers (only allowed once)
     let tcp_rx = TCP_RX_BUFFER.take();
     let tcp_tx = TCP_TX_BUFFER.take();
-
-    // Pass Stack by value to embassy-net TcpSocket
     let mut socket = TcpSocket::new(stack, tcp_rx, tcp_tx);
 
-    // TODO broker details
-    let broker_ip = Ipv4Address::new(192, 168, 1, 100);
-    let broker_port = 1883;
-
-    match socket.connect((broker_ip, broker_port)).await {
+    match socket.connect(mqtt_broker_endpoint()).await {
         Ok(_) => info!("Connected TCP to MQTT broker"),
         Err(e) => {
             info!("TCP connect failed: {:?}", e);
@@ -39,24 +34,20 @@ pub async fn mqtt_task(stack: Stack<'static>) {
         }
     }
 
-    // Safely take MQTT buffers
     let mqtt_tx = MQTT_TX_BUF.take();
     let mqtt_rx = MQTT_RX_BUF.take();
 
-    let mqtt_tx_len = mqtt_tx.len();
-    let mqtt_rx_len = mqtt_rx.len();
-
-    // RNG
+    // Config
     let rng = CountingRng(0);
-
-    // Build config
     let mut cfg: ClientConfig<'static, 8, _> = ClientConfig::new(MqttVersion::MQTTv5, rng);
     cfg.keep_alive = 60;
     cfg.add_client_id("esp32-client");
     // cfg.add_username("user");
     // cfg.add_password("pass");
 
-    // Build MQTT client
+    let mqtt_tx_len = mqtt_tx.len();
+    let mqtt_rx_len = mqtt_rx.len();
+
     let mut client = MqttClient::new(socket, mqtt_tx, mqtt_tx_len, mqtt_rx, mqtt_rx_len, cfg);    
 
     // Connect
@@ -82,7 +73,6 @@ pub async fn mqtt_task(stack: Stack<'static>) {
         Err(reason) => info!("MQTT publish failed: {:?}", reason),
     }
 
-    // Keep alive
     loop {
         if let Err(reason) = client.send_ping().await {
             info!("MQTT ping failed: {:?}", reason);
diff --git a/final/src/mqtt/config.rs b/final/src/mqtt/config.rs
new file mode 100644
index 0000000..c20d357
--- /dev/null
+++ b/final/src/mqtt/config.rs
@@ -0,0 +1,122 @@
+// src/mqtt/config.rs
+#![allow(dead_code)]
+
+use embassy_net::{IpAddress, Ipv4Address, Ipv6Address};
+
+// Compile-time values injected by build.rs
+const BROKER_IP: &str = env!("BROKER_IP");
+const BROKER_PORT: &str = env!("BROKER_PORT");
+
+pub fn mqtt_broker_endpoint() -> (IpAddress, u16) {
+    (parse_ip(BROKER_IP), parse_port(BROKER_PORT))
+}
+
+fn parse_port(s: &str) -> u16 {
+    let p: u16 = s
+        .parse()
+        .unwrap_or_else(|_| panic!("BROKER_PORT must be a valid u16 (1..=65535)"));
+    assert!(p != 0, "BROKER_PORT cannot be 0");
+    p
+}
+
+fn parse_ip(s: &str) -> IpAddress {
+    if s.contains(':') {
+        IpAddress::Ipv6(parse_ipv6(s))
+    } else {
+        IpAddress::Ipv4(parse_ipv4(s))
+    }
+}
+
+fn parse_ipv4(s: &str) -> Ipv4Address {
+    let mut it = s.split('.');
+    let a = parse_octet(it.next(), 1);
+    let b = parse_octet(it.next(), 2);
+    let c = parse_octet(it.next(), 3);
+    let d = parse_octet(it.next(), 4);
+    assert!(it.next().is_none(), "Too many IPv4 octets");
+    Ipv4Address::new(a, b, c, d)
+}
+
+fn parse_octet(part: Option<&str>, idx: usize) -> u8 {
+    let p = part.unwrap_or_else(|| panic!("IPv4 missing octet {}", idx));
+    let v: u16 = p
+        .parse()
+        .unwrap_or_else(|_| panic!("Invalid IPv4 octet {}: {}", idx, p));
+    assert!(v <= 255, "IPv4 octet {} out of range: {}", idx, v);
+    v as u8
+}
+
+// Minimal IPv6 parser with '::' compression. Does not handle IPv4-embedded IPv6.
+fn parse_ipv6(s: &str) -> Ipv6Address {
+    assert!(
+        !s.contains('.'),
+        "IPv4-embedded IPv6 like ::ffff:192.0.2.1 not supported; \
+         use pure hex IPv6"
+    );
+
+    let has_double = s.contains("::");
+    let (left_s, right_s) = if has_double {
+        let mut sp = s.splitn(2, "::");
+        (sp.next().unwrap_or(""), sp.next().unwrap_or(""))
+    } else {
+        (s, "")
+    };
+
+    let mut left = [0u16; 8];
+    let mut right = [0u16; 8];
+    let mut ll = 0usize;
+    let mut rl = 0usize;
+
+    if !left_s.is_empty() {
+        for part in left_s.split(':') {
+            left[ll] = parse_group(part);
+            ll += 1;
+            assert!(ll <= 8, "Too many IPv6 groups on the left");
+        }
+    }
+
+    if !right_s.is_empty() {
+        for part in right_s.split(':') {
+            right[rl] = parse_group(part);
+            rl += 1;
+            assert!(rl <= 8, "Too many IPv6 groups on the right");
+        }
+    }
+
+    let zeros = if has_double {
+        assert!(ll + rl < 8, "Invalid IPv6 '::' usage");
+        8 - (ll + rl)
+    } else {
+        assert!(ll == 8, "IPv6 must have 8 groups without '::'");
+        0
+    };
+
+    let mut g = [0u16; 8];
+    let mut idx = 0usize;
+
+    for i in 0..ll {
+        g[idx] = left[i];
+        idx += 1;
+    }
+    for _ in 0..zeros {
+        g[idx] = 0;
+        idx += 1;
+    }
+    for i in 0..rl {
+        g[idx] = right[i];
+        idx += 1;
+    }
+    assert!(idx == 8, "IPv6 did not resolve to 8 groups");
+
+    Ipv6Address::new(g[0], g[1], g[2], g[3], g[4], g[5], g[6], g[7])
+}
+
+fn parse_group(part: &str) -> u16 {
+    assert!(
+        !part.is_empty(),
+        "Empty IPv6 group (use '::' instead for compression)"
+    );
+    assert!(part.len() <= 4, "IPv6 group too long: {}", part);
+    u16::from_str_radix(part, 16)
+        .unwrap_or_else(|_| panic!("Invalid IPv6 hex group: {}", part))
+}
diff --git a/final/src/mqtt/mod.rs b/final/src/mqtt/mod.rs
index 9cc7d66..ef0bd6d 100644
--- a/final/src/mqtt/mod.rs
+++ b/final/src/mqtt/mod.rs
@@ -1,2 +1,4 @@
+// src/mqtt/mod.rs
 
 pub mod client;
+pub mod config;