diff --git a/Cargo.toml b/Cargo.toml
index e9b6669..fec06cd 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "yps"
-version = "0.1.1"
+version = "0.1.2"
 edition = "2024"
 license = "MIT"
 readme = "README.md"
@@ -12,5 +12,6 @@ repository = "https://github.com/YGGverse/yps"
 [dependencies]
 anyhow = "1.0"
 clap = { version = "4.5", features = ["derive"] }
+colored = "3.0"
 serde = { version = "1.0", features = ["derive"] }
 serde_json = "1.0"
diff --git a/src/main.rs b/src/main.rs
index ff1afb6..643b777 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -3,6 +3,7 @@ mod udp;
 mod yggdrasil;
 
 use anyhow::Result;
+use colored::*;
 use config::Config;
 use std::{
     net::{IpAddr, SocketAddr, TcpStream},
@@ -20,82 +21,92 @@ fn main() -> Result<()> {
     if !config.tcp && config.udp.is_none() {
         panic!("at least one TCP or UDP protocol is required for scan!")
     }
-    let latency = config.latency.map(Duration::from_secs); // parse once
     let mut ygg = Yggdrasil::init(&config.socket)?;
-    let mut tcp: Option<Vec<SocketAddr>> = if config.tcp {
+    let mut key: Vec<String> = Vec::with_capacity(config.index_capacity);
+    let mut tcp = if config.tcp {
         Some(Vec::with_capacity(config.index_capacity))
     } else {
         None
     };
     let mut udp = config.udp.as_ref().map(|bind| {
         let server = Udp::init(bind).unwrap();
-        let index: Vec<SocketAddr> = Vec::with_capacity(config.index_capacity);
+        let index = Vec::with_capacity(config.index_capacity);
         (index, server)
     });
+    println!("crawler started...");
     // get initial peers to crawl
-    if config.debug {
-        println!("get initial peers to crawl...");
-    }
     let p = ygg.peers()?;
     if p.status != "success" {
         todo!()
     }
     // start crawler
     for peer in p.response.unwrap().peers {
-        crawl(peer.key, latency, &config, &mut ygg, &mut tcp, &mut udp)?;
+        crawl(peer.key, &config, &mut ygg, &mut key, &mut tcp, &mut udp)?;
     }
     Ok(())
 }
 
 fn crawl(
-    key: String,
-    latency: Option<Duration>,
+    k: String,
     config: &Config,
     ygg: &mut Yggdrasil,
+    key: &mut Vec<String>,
     tcp: &mut Option<Vec<SocketAddr>>,
     udp: &mut Option<(Vec<SocketAddr>, Udp)>,
 ) -> Result<()> {
-    if config.debug {
-        println!("get peers for `{}`...", &key);
-    }
-    let p = ygg.remote_peers(key)?;
-    if p.status != "success" {
-        todo!()
-    }
-    for (host, peers) in p.response.unwrap() {
-        for port in &config.port {
-            let address = SocketAddr::new(IpAddr::V6(host), *port);
-            if let Some(index) = tcp {
-                if !index.contains(&address) {
-                    let url = format!("tcp://{address}");
-                    if config.debug {
-                        println!("try `{url}`...");
-                    }
-                    if TcpStream::connect_timeout(&address, Duration::from_secs(1)).is_ok() {
-                        println!("{url}");
-                    }
-                    index.push(address)
-                }
-            }
-            if let Some((index, server)) = udp {
-                let url = format!("udp://{address}");
-                if !index.contains(&address) {
-                    if config.debug {
-                        println!("try `{url}`...");
-                    }
-                    if server.check(address) {
-                        println!("{url}");
-                    }
-                    index.push(address)
-                }
-            }
+    if !key.contains(&k) {
+        if config.debug {
+            println!("get peers for `{k}`...");
         }
-        for k in peers.keys {
-            if let Some(l) = latency {
-                std::thread::sleep(l);
+        let p = ygg.remote_peers(&k)?;
+        if p.status == "success" {
+            key.push(k);
+            for (host, peers) in p.response.unwrap() {
+                for port in &config.port {
+                    let address = SocketAddr::new(IpAddr::V6(host), *port);
+                    if let Some(i) = tcp {
+                        if !i.contains(&address) {
+                            let url = format!("tcp://{address}");
+                            if TcpStream::connect_timeout(&address, Duration::from_secs(1)).is_ok()
+                            {
+                                println!("\t{}: {url}", SUCCESS.green())
+                            } else if config.debug {
+                                println!("\t{}: {url}", FAILURE.red());
+                            }
+                            i.push(address)
+                        }
+                    }
+                    if let Some((i, server)) = udp {
+                        let url = format!("udp://{address}");
+                        if !i.contains(&address) {
+                            if server.check(address) {
+                                println!("\t{}: {url}", SUCCESS.green());
+                            } else if config.debug {
+                                println!("\t{}: {url}", FAILURE.red());
+                            }
+                            i.push(address)
+                        }
+                    }
+                }
+                for k in peers.keys {
+                    if let Some(l) = config.latency {
+                        std::thread::sleep(Duration::from_secs(l));
+                    }
+                    crawl(k, config, ygg, key, tcp, udp)?;
+                }
             }
-            crawl(k, latency, config, ygg, tcp, udp)?;
+        } else if config.debug {
+            println!(
+                "\t{}: peer `{k}` return status `{}`, skip.",
+                WARNING.yellow(),
+                p.status
+            );
+            key.push(k) // ban
         }
     }
     Ok(())
 }
+
+const FAILURE: &str = "FAILURE";
+const SUCCESS: &str = "SUCCESS";
+const WARNING: &str = "WARNING";
diff --git a/src/yggdrasil.rs b/src/yggdrasil.rs
index 89bab8b..ed2a694 100644
--- a/src/yggdrasil.rs
+++ b/src/yggdrasil.rs
@@ -25,7 +25,7 @@ impl Yggdrasil {
 
     pub fn remote_peers(
         &mut self,
-        public_key: String,
+        public_key: &str,
     ) -> Result<Response<HashMap<Ipv6Addr, RemotePeers>>> {
         let r: Response<HashMap<Ipv6Addr, RemotePeers>> = serde_json::from_slice(&self.request(
             format!("{{\"keepalive\":true,\"request\":\"debug_remotegetpeers\",\"arguments\":{{\"key\":\"{public_key}\"}}}}")