diff --git a/src/interface/mod.rs b/src/interface/mod.rs
index 24be31f..eeeeb87 100644
--- a/src/interface/mod.rs
+++ b/src/interface/mod.rs
@@ -6,14 +6,16 @@ pub mod types;
 
 use crate::interface::interface::Interface;
 
+#[cfg(feature = "gateway")]
+use std::net::IpAddr;
+
 /// Get default Network Interface
 #[cfg(feature = "gateway")]
 pub fn get_default_interface() -> Result<Interface, String> {
     use crate::net::ip::get_local_ipaddr;
-    use std::net::IpAddr;
 
-    let interfaces: Vec<Interface> = interfaces();
-    for iface in &interfaces {
+    let ifaces: Vec<Interface> = interfaces();
+    for iface in &ifaces {
         if iface.default {
             return Ok(iface.clone());
         }
@@ -22,26 +24,46 @@ pub fn get_default_interface() -> Result<Interface, String> {
         Some(local_ip) => local_ip,
         None => return Err(String::from("Local IP address not found")),
     };
-    for iface in interfaces {
+    let idx: u32 = pick_default_iface_index(&ifaces, local_ip)
+        .ok_or_else(|| String::from("Default interface not found"))?;
+    ifaces
+        .into_iter()
+        .find(|it| it.index == idx)
+        .ok_or_else(|| String::from("Default interface not found"))
+}
+
+/// Get a list of available Network Interfaces
+pub fn get_interfaces() -> Vec<Interface> {
+    interfaces()
+}
+
+/// Pick the interface index corresponding to the system's default route.
+/// Prefers exact IP match; falls back to subnet containment.
+#[cfg(feature = "gateway")]
+pub(crate) fn pick_default_iface_index(ifaces: &[Interface], local_ip: IpAddr) -> Option<u32> {
+    let mut subnet_candidate: Option<u32> = None;
+
+    for iface in ifaces {
         match local_ip {
-            IpAddr::V4(local_ipv4) => {
-                if iface.ipv4.iter().any(|x| x.addr() == local_ipv4) {
-                    return Ok(iface);
+            IpAddr::V4(ipv4) => {
+                if iface.ipv4.iter().any(|x| x.addr() == ipv4) {
+                    return Some(iface.index);
+                }
+                if subnet_candidate.is_none() && iface.ipv4.iter().any(|x| x.contains(&ipv4)) {
+                    subnet_candidate = Some(iface.index);
                 }
             }
-            IpAddr::V6(local_ipv6) => {
-                if iface.ipv6.iter().any(|x| x.addr() == local_ipv6) {
-                    return Ok(iface);
+            IpAddr::V6(ipv6) => {
+                if iface.ipv6.iter().any(|x| x.addr() == ipv6) {
+                    return Some(iface.index);
+                }
+                if subnet_candidate.is_none() && iface.ipv6.iter().any(|x| x.contains(&ipv6)) {
+                    subnet_candidate = Some(iface.index);
                 }
             }
         }
     }
-    Err(String::from("Default Interface not found"))
-}
-
-/// Get a list of available Network Interfaces
-pub fn get_interfaces() -> Vec<Interface> {
-    interfaces()
+    subnet_candidate
 }
 
 pub(crate) fn interfaces() -> Vec<Interface> {
diff --git a/src/os/android/interface.rs b/src/os/android/interface.rs
index 1f90bdb..bf91abc 100644
--- a/src/os/android/interface.rs
+++ b/src/os/android/interface.rs
@@ -11,15 +11,11 @@ use std::net::{Ipv4Addr, Ipv6Addr};
 #[cfg(feature = "gateway")]
 use crate::net::device::NetworkDevice;
 #[cfg(feature = "gateway")]
-use crate::net::ip::get_local_ipaddr;
-#[cfg(feature = "gateway")]
 use crate::os::linux::procfs;
 #[cfg(feature = "gateway")]
 use crate::os::unix::dns::get_system_dns_conf;
 #[cfg(feature = "gateway")]
 use std::collections::HashMap;
-#[cfg(feature = "gateway")]
-use std::net::IpAddr;
 
 fn push_ipv4(v: &mut Vec<Ipv4Net>, add: (Ipv4Addr, u8)) {
     if v.iter()
@@ -55,10 +51,6 @@ fn calc_v6_scope_id(addr: &Ipv6Addr, ifindex: u32) -> u32 {
 
 pub fn interfaces() -> Vec<Interface> {
     let mut ifaces = Vec::new();
-
-    #[cfg(feature = "gateway")]
-    let local_ip_opt: Option<IpAddr> = get_local_ipaddr();
-
     // Fill ifaces via netlink first
     // If netlink fails, fallback to unix_interfaces
     match netlink::collect_interfaces() {
@@ -155,23 +147,14 @@ pub fn interfaces() -> Vec<Interface> {
         if iface.mtu.is_none() {
             iface.mtu = mtu::get_mtu(&iface.name);
         }
-
-        #[cfg(feature = "gateway")]
-        {
-            if let Some(local_ip) = local_ip_opt {
-                match local_ip {
-                    IpAddr::V4(local_ipv4) => {
-                        if iface.ipv4.iter().any(|x| x.addr() == local_ipv4) {
-                            iface.default = true;
-                            iface.dns_servers = get_system_dns_conf();
-                        }
-                    }
-                    IpAddr::V6(local_ipv6) => {
-                        if iface.ipv6.iter().any(|x| x.addr() == local_ipv6) {
-                            iface.default = true;
-                            iface.dns_servers = get_system_dns_conf();
-                        }
-                    }
+    }
+    #[cfg(feature = "gateway")]
+    {
+        if let Some(local_ip) = crate::net::ip::get_local_ipaddr() {
+            if let Some(idx) = crate::interface::pick_default_iface_index(&ifaces, local_ip) {
+                if let Some(iface) = ifaces.iter_mut().find(|it| it.index == idx) {
+                    iface.default = true;
+                    iface.dns_servers = get_system_dns_conf();
                 }
             }
         }
diff --git a/src/os/bsd/interface.rs b/src/os/bsd/interface.rs
index df4595d..b591d6d 100644
--- a/src/os/bsd/interface.rs
+++ b/src/os/bsd/interface.rs
@@ -1,6 +1,3 @@
-#[cfg(feature = "gateway")]
-use std::net::IpAddr;
-
 use crate::{interface::interface::Interface, os::unix::interface::unix_interfaces};
 
 pub fn interfaces() -> Vec<Interface> {
@@ -12,31 +9,23 @@ pub fn interfaces() -> Vec<Interface> {
     {
         use crate::os::unix::dns::get_system_dns_conf;
 
-        let mut interfaces: Vec<Interface> = unix_interfaces();
-        let local_ip_opt: Option<IpAddr> = crate::net::ip::get_local_ipaddr();
+        let mut ifaces: Vec<Interface> = unix_interfaces();
 
         let gateway_map = super::route::get_gateway_map();
 
-        for iface in &mut interfaces {
+        for iface in &mut ifaces {
             if let Some(gateway) = gateway_map.get(&iface.index) {
                 iface.gateway = Some(gateway.clone());
             }
-
-            if let Some(local_ip) = local_ip_opt {
-                iface.ipv4.iter().for_each(|ipv4| {
-                    if IpAddr::V4(ipv4.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
-                iface.ipv6.iter().for_each(|ipv6| {
-                    if IpAddr::V6(ipv6.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
+        }
+        if let Some(local_ip) = crate::net::ip::get_local_ipaddr() {
+            if let Some(idx) = crate::interface::pick_default_iface_index(&ifaces, local_ip) {
+                if let Some(iface) = ifaces.iter_mut().find(|it| it.index == idx) {
+                    iface.default = true;
+                    iface.dns_servers = get_system_dns_conf();
+                }
             }
         }
-        interfaces
+        ifaces
     }
 }
diff --git a/src/os/ios/interface.rs b/src/os/ios/interface.rs
index 8fdd7a0..2b1265d 100644
--- a/src/os/ios/interface.rs
+++ b/src/os/ios/interface.rs
@@ -1,41 +1,29 @@
-#[cfg(feature = "gateway")]
-use std::net::IpAddr;
-
 use crate::{interface::interface::Interface, os::unix::interface::unix_interfaces};
 
 pub fn interfaces() -> Vec<Interface> {
-    let mut interfaces: Vec<Interface> = unix_interfaces();
-
-    #[cfg(feature = "gateway")]
-    let local_ip_opt: Option<IpAddr> = crate::net::ip::get_local_ipaddr();
-
+    #[cfg(not(feature = "gateway"))]
+    {
+        unix_interfaces()
+    }
     #[cfg(feature = "gateway")]
-    let gateway_map = crate::os::darwin::route::get_gateway_map();
+    {
+        use crate::os::unix::dns::get_system_dns_conf;
 
-    for iface in &mut interfaces {
-        #[cfg(feature = "gateway")]
-        {
-            use crate::os::unix::dns::get_system_dns_conf;
+        let mut ifaces: Vec<Interface> = unix_interfaces();
+        let gateway_map = crate::os::darwin::route::get_gateway_map();
+        for iface in &mut ifaces {
             if let Some(gateway) = gateway_map.get(&iface.index) {
                 iface.gateway = Some(gateway.clone());
             }
-
-            if let Some(local_ip) = local_ip_opt {
-                iface.ipv4.iter().for_each(|ipv4| {
-                    if IpAddr::V4(ipv4.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
-                iface.ipv6.iter().for_each(|ipv6| {
-                    if IpAddr::V6(ipv6.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
+        }
+        if let Some(local_ip) = crate::net::ip::get_local_ipaddr() {
+            if let Some(idx) = crate::interface::pick_default_iface_index(&ifaces, local_ip) {
+                if let Some(iface) = ifaces.iter_mut().find(|it| it.index == idx) {
+                    iface.default = true;
+                    iface.dns_servers = get_system_dns_conf();
+                }
             }
         }
+        ifaces
     }
-
-    interfaces
 }
diff --git a/src/os/linux/interface.rs b/src/os/linux/interface.rs
index cecf193..f98f82c 100644
--- a/src/os/linux/interface.rs
+++ b/src/os/linux/interface.rs
@@ -9,13 +9,9 @@ use std::net::{Ipv4Addr, Ipv6Addr};
 #[cfg(feature = "gateway")]
 use crate::net::device::NetworkDevice;
 #[cfg(feature = "gateway")]
-use crate::net::ip::get_local_ipaddr;
-#[cfg(feature = "gateway")]
 use crate::os::unix::dns::get_system_dns_conf;
 #[cfg(feature = "gateway")]
 use std::collections::HashMap;
-#[cfg(feature = "gateway")]
-use std::net::IpAddr;
 
 fn push_ipv4(v: &mut Vec<Ipv4Net>, add: (Ipv4Addr, u8)) {
     if v.iter()
@@ -51,10 +47,6 @@ fn calc_v6_scope_id(addr: &Ipv6Addr, ifindex: u32) -> u32 {
 
 pub fn interfaces() -> Vec<Interface> {
     let mut ifaces = Vec::new();
-
-    #[cfg(feature = "gateway")]
-    let local_ip_opt: Option<IpAddr> = get_local_ipaddr();
-
     // Fill ifaces via netlink first
     // If netlink fails, fallback to unix_interfaces
     match netlink::collect_interfaces() {
@@ -151,23 +143,14 @@ pub fn interfaces() -> Vec<Interface> {
         if iface.mtu.is_none() {
             iface.mtu = super::mtu::get_mtu(&iface.name);
         }
-
-        #[cfg(feature = "gateway")]
-        {
-            if let Some(local_ip) = local_ip_opt {
-                match local_ip {
-                    IpAddr::V4(local_ipv4) => {
-                        if iface.ipv4.iter().any(|x| x.addr() == local_ipv4) {
-                            iface.default = true;
-                            iface.dns_servers = get_system_dns_conf();
-                        }
-                    }
-                    IpAddr::V6(local_ipv6) => {
-                        if iface.ipv6.iter().any(|x| x.addr() == local_ipv6) {
-                            iface.default = true;
-                            iface.dns_servers = get_system_dns_conf();
-                        }
-                    }
+    }
+    #[cfg(feature = "gateway")]
+    {
+        if let Some(local_ip) = crate::net::ip::get_local_ipaddr() {
+            if let Some(idx) = crate::interface::pick_default_iface_index(&ifaces, local_ip) {
+                if let Some(iface) = ifaces.iter_mut().find(|it| it.index == idx) {
+                    iface.default = true;
+                    iface.dns_servers = get_system_dns_conf();
                 }
             }
         }
diff --git a/src/os/macos/interface.rs b/src/os/macos/interface.rs
index cd6876e..f2e28bd 100644
--- a/src/os/macos/interface.rs
+++ b/src/os/macos/interface.rs
@@ -1,6 +1,3 @@
-#[cfg(feature = "gateway")]
-use std::net::IpAddr;
-
 use crate::{
     interface::{interface::Interface, types::InterfaceType},
     os::unix::interface::unix_interfaces,
@@ -16,15 +13,12 @@ pub struct SCInterface {
 
 pub fn interfaces() -> Vec<Interface> {
     let type_map = super::types::get_if_type_map();
-    let mut interfaces: Vec<Interface> = unix_interfaces();
-
-    #[cfg(feature = "gateway")]
-    let local_ip_opt: Option<IpAddr> = crate::net::ip::get_local_ipaddr();
+    let mut ifaces: Vec<Interface> = unix_interfaces();
 
     #[cfg(feature = "gateway")]
     let gateway_map = crate::os::darwin::route::get_gateway_map();
 
-    for iface in &mut interfaces {
+    for iface in &mut ifaces {
         if let Some(sc_interface) = type_map.get(&iface.name) {
             iface.if_type = sc_interface.interface_type;
             iface.friendly_name = sc_interface.friendly_name.clone();
@@ -32,27 +26,24 @@ pub fn interfaces() -> Vec<Interface> {
 
         #[cfg(feature = "gateway")]
         {
-            use crate::os::unix::dns::get_system_dns_conf;
             if let Some(gateway) = gateway_map.get(&iface.index) {
                 iface.gateway = Some(gateway.clone());
             }
+        }
+    }
 
-            if let Some(local_ip) = local_ip_opt {
-                iface.ipv4.iter().for_each(|ipv4| {
-                    if IpAddr::V4(ipv4.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
-                iface.ipv6.iter().for_each(|ipv6| {
-                    if IpAddr::V6(ipv6.addr()) == local_ip {
-                        iface.dns_servers = get_system_dns_conf();
-                        iface.default = true;
-                    }
-                });
+    #[cfg(feature = "gateway")]
+    {
+        use crate::os::unix::dns::get_system_dns_conf;
+        if let Some(local_ip) = crate::net::ip::get_local_ipaddr() {
+            if let Some(idx) = crate::interface::pick_default_iface_index(&ifaces, local_ip) {
+                if let Some(iface) = ifaces.iter_mut().find(|it| it.index == idx) {
+                    iface.default = true;
+                    iface.dns_servers = get_system_dns_conf();
+                }
             }
         }
     }
 
-    interfaces
+    ifaces
 }