diff --git a/src/main.rs b/src/main.rs
index 704387f..aa683e1 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -16,6 +16,9 @@ use simple_endian::BigEndian;
 /// [RFC 8200 § 2]: https://www.rfc-editor.org/rfc/rfc791#section-3.2
 pub const ADDR_SIZE: usize = 4;
 
+pub const DHCP_SERVER_PORT: u16 = 67;
+pub const DHCP_CLIENT_PORT: u16 = 68;
+
 #[derive(Debug, Hash, PartialEq, Eq, PartialOrd, Ord, Clone, Copy, Default)]
 pub struct Ipv4Addr(pub [u8; ADDR_SIZE]);
 
@@ -59,7 +62,6 @@ enum HType {
     Ethernet = 1u8.swap_bytes(),
 }
 
-#[derive(Debug, Clone)]
 #[repr(C, packed)]
 struct Header {
     op: DhcpType,
@@ -368,13 +370,26 @@ pub fn cvt(t: i32) -> io::Result<i32> {
     }
 }
 
+fn get_nicname<'a>() -> &'a str {
+    static CACHED: Once<String> = Once::new();
+
+    CACHED.call_once(|| {
+        let nic_name = std::env::args().nth(1).unwrap_or(DEFAULT_NIC.to_string());
+
+        get_index(&nic_name)
+            .unwrap_or_else(|nic_name| panic!("[ DHCPD ] (EE) invalid NIC name {}", nic_name));
+
+        nic_name
+    })
+}
+
 fn get_macaddress<'a>() -> &'a [u8; 6] {
     static CACHED: Once<[u8; 6]> = Once::new();
     CACHED
         .try_call_once(|| unsafe {
             let fd = cvt(libc::socket(libc::AF_INET, libc::SOCK_DGRAM, 0))?;
 
-            let macaddr = IfReq::new(DEFAULT_NIC);
+            let macaddr = IfReq::new(get_nicname());
             cvt(libc::ioctl(fd, libc::SIOCGIFHWADDR, &macaddr))?;
 
             Ok::<[u8; 6], io::Error>(macaddr.macaddr())
@@ -467,9 +482,16 @@ fn configure(interface: &str, ip: Ipv4Addr, subnet_mask: Ipv4Addr) -> io::Result
 
 const DEFAULT_NIC: &str = "eth0"; // FIXME: retrieve the default NIC from the kernel
 
+fn get_index(nic: &str) -> io::Result<libc::c_uint> {
+    let ifname = std::ffi::CString::new(nic)?;
+    match unsafe { libc::if_nametoindex(ifname.as_ptr()) } {
+        0 => Err(io::Error::last_os_error()),
+        index => Ok(index),
+    }
+}
+
 pub fn main() -> Result<(), Box<dyn Error>> {
-    let socket = UdpSocket::bind(("0.0.0.0", 68))?;
-    socket.connect(("255.255.255.255", 67))?;
+    let socket = UdpSocket::bind(("0.0.0.0", DHCP_CLIENT_PORT))?;
 
     let mut discover_header = Header::new(HType::Ethernet);
     discover_header
@@ -479,7 +501,7 @@ pub fn main() -> Result<(), Box<dyn Error>> {
         .set_host_name("Aero")
         .set_parameter_request_list();
 
-    socket.send(discover_header.as_slice())?;
+    socket.send_to(discover_header.as_slice(), "255.255.255.255:67")?;
 
     let mut offer = Header::new(HType::Ethernet);
     socket.recv(offer.as_slice_mut())?;
@@ -495,7 +517,7 @@ pub fn main() -> Result<(), Box<dyn Error>> {
         .set_host_name("Aero")
         .set_parameter_request_list();
 
-    socket.send(request_header.as_slice())?;
+    socket.send_to(request_header.as_slice(), "255.255.255.255:67")?;
 
     let mut ack = Header::new(HType::Ethernet);
     socket.recv(ack.as_slice_mut())?;
@@ -519,7 +541,7 @@ pub fn main() -> Result<(), Box<dyn Error>> {
     let subnet_mask = subnet_mask.unwrap();
     let dns = dns.unwrap();
 
-    configure(DEFAULT_NIC, ack.your_ip, subnet_mask)?;
+    configure(get_nicname(), ack.your_ip, subnet_mask)?;
 
     println!("[ DHCPD ] (!!) Configured:");
     println!("[ DHCPD ] (!!) IP:              {}", ack.your_ip);