diff --git a/tun/src/unix/linux/mod.rs b/tun/src/unix/linux/mod.rs
index 82a2125..7167a32 100644
--- a/tun/src/unix/linux/mod.rs
+++ b/tun/src/unix/linux/mod.rs
@@ -75,6 +75,16 @@ impl TunInterface {
         self.perform(|fd| unsafe { sys::if_set_mtu(fd, &iff) })?;
     }
 
+    #[throws]
+    pub fn set_netmask(&self, addr: Ipv4Addr) {
+        let addr = SockAddr::from(SocketAddrV4::new(addr, 0));
+
+        let mut iff = self.ifreq()?;
+        iff.ifr_ifru.ifru_netmask = unsafe { *addr.as_ptr() };
+
+        self.perform(|fd| unsafe { sys::if_set_netmask(fd, &iff) })?;
+    }
+
     #[throws]
     pub fn ipv4_addr(&self) -> Ipv4Addr {
         let mut iff = self.ifreq()?;
@@ -92,6 +102,17 @@ impl TunInterface {
         mtu
     }
 
+    #[throws]
+    pub fn netmask(&self) -> Ipv4Addr {
+        let mut iff = self.ifreq()?;
+        self.perform(|fd| unsafe { sys::if_get_netmask(fd, &mut iff) })?;
+
+        let netmask =
+            unsafe { *(&iff.ifr_ifru.ifru_netmask as *const _ as *const sys::sockaddr_in) };
+
+        Ipv4Addr::from(u32::from_be(netmask.sin_addr.s_addr))
+    }
+
     #[throws]
     fn perform<R>(&self, perform: impl FnOnce(RawFd) -> Result<R, nix::Error>) -> R {
         let socket = Socket::new(Domain::IPV4, Type::DGRAM, None)?;
@@ -101,6 +122,7 @@ impl TunInterface {
 
 mod test {
     use super::TunInterface;
+    use std::net::Ipv4Addr;
 
     #[test]
     fn mtu() {
@@ -110,4 +132,15 @@ mod test {
 
         assert_eq!(interf.mtu().unwrap(), 500);
     }
+
+    #[test]
+    fn netmask() {
+        let interf = TunInterface::new().unwrap();
+
+        let addr = Ipv4Addr::new(255, 0, 0, 0);
+
+        interf.set_netmask(addr);
+
+        assert_eq!(interf.netmask().unwrap(), addr);
+    }
 }
diff --git a/tun/src/unix/linux/sys.rs b/tun/src/unix/linux/sys.rs
index e8e373f..8bac12d 100644
--- a/tun/src/unix/linux/sys.rs
+++ b/tun/src/unix/linux/sys.rs
@@ -2,6 +2,7 @@ use nix::{ioctl_read_bad, ioctl_write_ptr_bad, request_code_read, request_code_w
 use std::mem::size_of;
 
 pub use libc::ifreq;
+pub use libc::sockaddr;
 pub use libc::sockaddr_in;
 
 ioctl_write_ptr_bad!(
@@ -17,6 +18,8 @@ ioctl_read_bad!(
 ioctl_read_bad!(if_get_index, libc::SIOCGIFINDEX, libc::ifreq);
 ioctl_read_bad!(if_get_addr, libc::SIOCGIFADDR, libc::ifreq);
 ioctl_read_bad!(if_get_mtu, libc::SIOCGIFMTU, libc::ifreq);
+ioctl_read_bad!(if_get_netmask, libc::SIOCGIFNETMASK, libc::ifreq);
 
 ioctl_write_ptr_bad!(if_set_addr, libc::SIOCSIFADDR, libc::ifreq);
 ioctl_write_ptr_bad!(if_set_mtu, libc::SIOCSIFMTU, libc::ifreq);
+ioctl_write_ptr_bad!(if_set_netmask, libc::SIOCSIFNETMASK, libc::ifreq);