diff --git a/src/constants.rs b/src/constants.rs
index 8d014ed..2392c02 100644
--- a/src/constants.rs
+++ b/src/constants.rs
@@ -8,6 +8,11 @@ pub const ICMP_ECHO_REPLY: u8 = 0;
 pub const ICMP6_ECHO_REQUEST: u8 = 128;
 pub const ICMP6_ECHO_REPLY: u8 = 129;
 pub const ICMP_HEADER_LEN: usize = 8;
+pub const ICMP_TYPE_OFFSET: usize = 0;
+pub const ICMP_ID_OFFSET: usize = 4;
+pub const ICMP_SEQ_OFFSET: usize = 6;
+pub const ICMP_MIN_LEN: usize = 8;
+pub const IPV4_MIN_HDR_LEN: usize = 20;
 
 /* Default values */
 pub const _DEFAULT_INTERVAL_MS: u64 = 10;
@@ -24,6 +29,7 @@ pub const _MAX_GENERATE: usize = 131_072;
 pub const _MAX_TARGET_NAME: usize = 255;
 
 /* Response flags */
+pub const RESP_TIMES_CAP: usize = 1000;
 pub const _RESP_WAITING: i64 = -1;
 pub const _RESP_UNUSED: i64 = -2;
 pub const _RESP_TIMEOUT: i64 = -4;
diff --git a/src/socket.rs b/src/socket.rs
index b8641e7..34ee9fa 100644
--- a/src/socket.rs
+++ b/src/socket.rs
@@ -2,11 +2,13 @@ use libc::{
   c_void, recvfrom, sendto, sockaddr, socklen_t,
   AF_INET, AF_INET6, IPPROTO_ICMP, IPPROTO_ICMPV6, SOCK_DGRAM, SOCK_RAW,
 };
+use std::io::ErrorKind;
 use std::net::{Ipv4Addr, Ipv6Addr};
 use std::os::unix::io::RawFd;
 
 use crate::constants::{
   ICMP6_ECHO_REPLY, ICMP6_ECHO_REQUEST, ICMP_ECHO_REPLY, ICMP_ECHO_REQUEST, ICMP_HEADER_LEN,
+  ICMP_TYPE_OFFSET, ICMP_ID_OFFSET, ICMP_SEQ_OFFSET, ICMP_MIN_LEN, IPV4_MIN_HDR_LEN,
 };
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
@@ -24,15 +26,25 @@ pub fn open_raw_socket(is_ipv6: bool) -> Result<(RawFd, SocketKind, Option<u16>)
 
   let fd = unsafe { libc::socket(domain, SOCK_RAW, proto) };
   if fd >= 0 {
-    set_nonblocking(fd);
+    if let Err(e) = set_nonblocking(fd) {
+      eprintln!("Warning: set_nonblocking failed for RAW socket: {}", e);
+    }
     return Ok((fd, SocketKind::Raw, None));
   }
 
   let fd = unsafe { libc::socket(domain, SOCK_DGRAM, proto) };
   if fd >= 0 {
-    set_nonblocking(fd);
-    let assigned_id = dgram_bind_and_get_id(fd, is_ipv6);
-    return Ok((fd, SocketKind::Dgram, assigned_id));
+    if let Err(e) = set_nonblocking(fd) {
+      eprintln!("Warning: set_nonblocking failed for DGRAM socket: {}", e);
+    }
+
+    match dgram_bind_and_get_id(fd, is_ipv6) {
+      Ok(assigned_id) => return Ok((fd, SocketKind::Dgram, assigned_id)),
+      Err(e) => {
+        unsafe { libc::close(fd) };
+        return Err(format!("DGRAM socket bind/getsockname failed: {}", e));
+      }
+    }
   }
 
   Err(format!(
@@ -44,7 +56,7 @@ pub fn open_raw_socket(is_ipv6: bool) -> Result<(RawFd, SocketKind, Option<u16>)
   ))
 }
 
-fn dgram_bind_and_get_id(fd: RawFd, is_ipv6: bool) -> Option<u16> {
+fn dgram_bind_and_get_id(fd: RawFd, is_ipv6: bool) -> Result<Option<u16>, std::io::Error> {
   unsafe {
     if is_ipv6 {
       let mut sa: libc::sockaddr_in6 = std::mem::zeroed();
@@ -54,13 +66,20 @@ fn dgram_bind_and_get_id(fd: RawFd, is_ipv6: bool) -> Option<u16> {
         &sa as *const _ as *const libc::sockaddr,
         std::mem::size_of::<libc::sockaddr_in6>() as socklen_t,
       );
-      if r < 0 { return None; }
+      if r < 0 {
+        return Err(std::io::Error::last_os_error());
+      }
 
       let mut sa2: libc::sockaddr_in6 = std::mem::zeroed();
       let mut len = std::mem::size_of::<libc::sockaddr_in6>() as socklen_t;
       let r = libc::getsockname(fd, &mut sa2 as *mut _ as *mut libc::sockaddr, &mut len);
-      if r < 0 || sa2.sin6_port == 0 { return None; }
-      Some(u16::from_be(sa2.sin6_port))
+      if r < 0 {
+        return Err(std::io::Error::last_os_error());
+      }
+      if sa2.sin6_port == 0 {
+        return Ok(None);
+      }
+      Ok(Some(u16::from_be(sa2.sin6_port)))
     } else {
       let mut sa: libc::sockaddr_in = std::mem::zeroed();
       sa.sin_family = AF_INET as libc::sa_family_t;
@@ -69,38 +88,52 @@ fn dgram_bind_and_get_id(fd: RawFd, is_ipv6: bool) -> Option<u16> {
         &sa as *const _ as *const libc::sockaddr,
         std::mem::size_of::<libc::sockaddr_in>() as socklen_t,
       );
-      if r < 0 { return None; }
+      if r < 0 {
+        return Err(std::io::Error::last_os_error());
+      }
 
       let mut sa2: libc::sockaddr_in = std::mem::zeroed();
       let mut len = std::mem::size_of::<libc::sockaddr_in>() as socklen_t;
       let r = libc::getsockname(fd, &mut sa2 as *mut _ as *mut libc::sockaddr, &mut len);
-      if r < 0 || sa2.sin_port == 0 { return None; }
-      Some(u16::from_be(sa2.sin_port))
+      if r < 0 {
+        return Err(std::io::Error::last_os_error());
+      }
+      if sa2.sin_port == 0 {
+        return Ok(None);
+      }
+      Ok(Some(u16::from_be(sa2.sin_port)))
     }
   }
 }
 
-fn set_nonblocking(fd: RawFd) {
+fn set_nonblocking(fd: RawFd) -> Result<(), std::io::Error> {
   unsafe {
     let flags = libc::fcntl(fd, libc::F_GETFL, 0);
-    libc::fcntl(fd, libc::F_SETFL, flags | libc::O_NONBLOCK);
+    if flags < 0 {
+      return Err(std::io::Error::last_os_error());
+    }
+    let r = libc::fcntl(fd, libc::F_SETFL, flags | libc::O_NONBLOCK);
+    if r < 0 {
+      return Err(std::io::Error::last_os_error());
+    }
+    Ok(())
   }
 }
 
-pub fn build_icmp_packet(id: u16, seq: u16, data_size: usize, is_ipv6: bool, _kind: SocketKind) -> Vec<u8> {
+pub fn build_icmp_packet(id: u16, seq: u16, data_size: usize, is_ipv6: bool, kind: SocketKind) -> Vec<u8> {
   let total = ICMP_HEADER_LEN + data_size;
   let mut pkt = vec![0u8; total];
 
-  pkt[0] = if is_ipv6 { ICMP6_ECHO_REQUEST } else { ICMP_ECHO_REQUEST };
-  pkt[1] = 0;
-  pkt[2] = 0;
-  pkt[3] = 0;
-  pkt[4] = (id >> 8) as u8;
-  pkt[5] = (id & 0xFF) as u8;
-  pkt[6] = (seq >> 8) as u8;
-  pkt[7] = (seq & 0xFF) as u8;
+  pkt[ICMP_TYPE_OFFSET] = if is_ipv6 { ICMP6_ECHO_REQUEST } else { ICMP_ECHO_REQUEST };
+  pkt[1] = 0; // Code
+  pkt[2] = 0; // Checksum high
+  pkt[3] = 0; // Checksum low
+  pkt[ICMP_ID_OFFSET] = (id >> 8) as u8;
+  pkt[ICMP_ID_OFFSET + 1] = (id & 0xFF) as u8;
+  pkt[ICMP_SEQ_OFFSET] = (seq >> 8) as u8;
+  pkt[ICMP_SEQ_OFFSET + 1] = (seq & 0xFF) as u8;
 
-  for (i, b) in pkt[8..].iter_mut().enumerate() {
+  for (i, b) in pkt[ICMP_MIN_LEN..].iter_mut().enumerate() {
     *b = (i & 0xFF) as u8;
   }
 
@@ -108,6 +141,8 @@ pub fn build_icmp_packet(id: u16, seq: u16, data_size: usize, is_ipv6: bool, _ki
     let cksum = icmp_checksum(&pkt);
     pkt[2] = (cksum >> 8) as u8;
     pkt[3] = (cksum & 0xFF) as u8;
+  } else if kind == SocketKind::Raw {
+    eprintln!("Warning: ICMPv6 checksum not computed for RAW socket – packet may be dropped");
   }
 
   pkt
@@ -170,6 +205,45 @@ pub struct ReceivedPing {
   pub raw_len: usize,
 }
 
+fn parse_icmp_packet(data: &[u8], is_ipv6: bool, kind: SocketKind, expected_id: Option<u16>) -> Option<u16> {
+  let icmp = if !is_ipv6 && kind == SocketKind::Raw {
+    if data.len() < IPV4_MIN_HDR_LEN + ICMP_MIN_LEN {
+      return None;
+    }
+    let ihl = ((data[0] & 0x0F) as usize) * 4;
+    if data.len() < ihl + ICMP_MIN_LEN {
+      return None;
+    }
+    &data[ihl..]
+  } else {
+    if data.len() < ICMP_MIN_LEN {
+      return None;
+    }
+    data
+  };
+
+  let icmp_type = icmp[ICMP_TYPE_OFFSET];
+
+  let is_reply = if is_ipv6 {
+    icmp_type == ICMP6_ECHO_REPLY
+  } else {
+    icmp_type == ICMP_ECHO_REPLY
+  };
+
+  if !is_reply {
+    return None;
+  }
+
+  let id = u16::from_be_bytes([icmp[ICMP_ID_OFFSET], icmp[ICMP_ID_OFFSET + 1]]);
+  if let Some(eid) = expected_id {
+    if id != eid {
+      return None;
+    }
+  }
+
+  Some(u16::from_be_bytes([icmp[ICMP_SEQ_OFFSET], icmp[ICMP_SEQ_OFFSET + 1]]))
+}
+
 pub fn recv_ping(fd: RawFd, buf: &mut [u8], is_ipv6: bool, kind: SocketKind, expected_id: Option<u16>) -> Option<ReceivedPing> {
   let mut src: libc::sockaddr_storage = unsafe { std::mem::zeroed() };
   let mut src_len = std::mem::size_of::<libc::sockaddr_storage>() as socklen_t;
@@ -186,36 +260,16 @@ pub fn recv_ping(fd: RawFd, buf: &mut [u8], is_ipv6: bool, kind: SocketKind, exp
   };
 
   if n < 0 {
+    let err = std::io::Error::last_os_error();
+    if err.kind() != ErrorKind::WouldBlock {
+      eprintln!("recv_ping: recvfrom error: {}", err);
+    }
     return None;
   }
 
   let raw_len = n as usize;
   let data = &buf[..raw_len];
+  let seq = parse_icmp_packet(data, is_ipv6, kind, expected_id)?;
 
-  let icmp = if !is_ipv6 && kind == SocketKind::Raw {
-    if data.len() < 20 + 8 { return None; }
-    let ihl = ((data[0] & 0x0F) as usize) * 4;
-    if data.len() < ihl + 8 { return None; }
-    &data[ihl..]
-  } else {
-    if data.len() < 8 { return None; }
-    data
-  };
-
-  let icmp_type = icmp[0];
-  let is_reply = icmp_type == ICMP_ECHO_REPLY || icmp_type == ICMP6_ECHO_REPLY;
-  if !is_reply {
-    return None;
-  }
-
-  let id = u16::from_be_bytes([icmp[4], icmp[5]]);
-
-  if let Some(eid) = expected_id {
-    if id != eid { return None; }
-  }
-
-  Some(ReceivedPing {
-    seq: u16::from_be_bytes([icmp[6], icmp[7]]),
-    raw_len,
-  })
+  Some(ReceivedPing { seq, raw_len })
 }
\ No newline at end of file
diff --git a/src/types.rs b/src/types.rs
index c9dcc2e..118194a 100644
--- a/src/types.rs
+++ b/src/types.rs
@@ -1,5 +1,6 @@
 use std::net::IpAddr;
 use std::time::{Duration, Instant};
+use crate::constants::RESP_TIMES_CAP;
 
 #[derive(Debug)]
 pub struct HostEntry {
@@ -57,8 +58,12 @@ impl HostEntry {
       // count-mode: pre-allocated slot exists, write in place
       self.resp_times[idx] = Some(rtt);
     } else {
-      // loop/default-mode: resp_times is empty or shorter than ping_index, append dynamically so -s statistics are never empty
-      self.resp_times.push(Some(rtt));
+      if self.resp_times.len() < RESP_TIMES_CAP {
+        self.resp_times.push(Some(rtt));
+      } else {
+        let slot = (ping_index as usize) % RESP_TIMES_CAP;
+        self.resp_times[slot] = Some(rtt);
+      }
     }
   }