diff --git a/libs/hbb_common/src/proxy.rs b/libs/hbb_common/src/proxy.rs
index 1fe41b593..3418e4db1 100644
--- a/libs/hbb_common/src/proxy.rs
+++ b/libs/hbb_common/src/proxy.rs
@@ -251,6 +251,26 @@ impl ProxyScheme {
             }
         }
     }
+    pub fn get_host_and_port(&self) -> Result<String, ProxyError> {
+        match self {
+            ProxyScheme::Http { host, .. } => {
+                Ok(self.append_default_port(host, 80))
+            },
+            ProxyScheme::Https { host, .. } => {
+                Ok(self.append_default_port(host, 443))
+            },
+            ProxyScheme::Socks5 { addr, .. } => {
+                Ok(format!("{}", addr))
+            },
+        }
+    }
+    fn append_default_port(&self, host: &str, default_port: u16) -> String {
+        if host.contains(':') {
+            host.to_string()
+        } else {
+            format!("{}:{}", host, default_port)
+        }
+    }
 }
 
 
diff --git a/libs/hbb_common/src/socket_client.rs b/libs/hbb_common/src/socket_client.rs
index 634f49a65..fbd7ab3c5 100644
--- a/libs/hbb_common/src/socket_client.rs
+++ b/libs/hbb_common/src/socket_client.rs
@@ -6,8 +6,10 @@ use crate::{
 };
 use anyhow::Context;
 use std::net::SocketAddr;
+use log::info;
 use tokio::net::ToSocketAddrs;
 use tokio_socks::{IntoTargetAddr, TargetAddr};
+use crate::proxy::IntoProxyScheme;
 
 #[inline]
 pub fn check_port<T: std::string::ToString>(host: T, port: i32) -> String {
@@ -50,19 +52,15 @@ pub fn increase_port<T: std::string::ToString>(host: T, offset: i32) -> String {
 }
 
 pub fn test_if_valid_server(host: &str) -> String {
-    let host = check_port(host, 0);
-
+    info!("Testing server validity for host: {}", host);
     use std::net::ToSocketAddrs;
-    match Config::get_network_type() {
-        NetworkType::Direct => match host.to_socket_addrs() {
-            Err(err) => err.to_string(),
-            Ok(_) => "".to_owned(),
-        },
-        NetworkType::ProxySocks => match &host.into_target_addr() {
-            Err(err) => err.to_string(),
-            Ok(_) => "".to_owned(),
-        },
-    }
+    // Even if the current network type is a proxy type,
+    // the system DNS should be used to resolve the proxy server address.
+    host.into_proxy_scheme()
+        .and_then(|scheme| scheme.get_host_and_port())
+        .and_then(|domain| domain.to_socket_addrs().map_err(Into::into))
+        .map(|_| "".to_owned()) // on success, return an empty string
+        .unwrap_or_else(|e| e.to_string()) // on error, convert the error into a string
 }
 
 pub trait IsResolvedSocketAddr {