diff --git a/crates/librqbit/src/lib.rs b/crates/librqbit/src/lib.rs
index 110781d..f8543c9 100644
--- a/crates/librqbit/src/lib.rs
+++ b/crates/librqbit/src/lib.rs
@@ -93,10 +93,14 @@ pub use librqbit_core::torrent_metainfo::*;
 mod tests;
 
 /// The cargo version of librqbit.
-pub fn version() -> &'static str {
+pub const fn version() -> &'static str {
     env!("CARGO_PKG_VERSION")
 }
 
+pub const fn client_name_and_version() -> &'static str {
+    concat!("rqbit ", env!("CARGO_PKG_VERSION"))
+}
+
 pub fn try_increase_nofile_limit() -> anyhow::Result<u64> {
     Ok(rlimit::increase_nofile_limit(1024 * 1024)?)
 }
diff --git a/crates/librqbit/src/peer_connection.rs b/crates/librqbit/src/peer_connection.rs
index 04a1be4..e39b3bf 100644
--- a/crates/librqbit/src/peer_connection.rs
+++ b/crates/librqbit/src/peer_connection.rs
@@ -200,7 +200,7 @@ impl<H: PeerConnectionHandler> PeerConnection<H> {
             .context("error reading handshake")?;
         let h_supports_extended = h.supports_extended();
         trace!(
-            peer_id=?h.peer_id,
+            peer_id=?Id20::new(h.peer_id),
             decoded_id=?try_decode_peer_id(Id20::new(h.peer_id)),
             "connected",
         );
@@ -247,6 +247,7 @@ impl<H: PeerConnectionHandler> PeerConnection<H> {
 
         if supports_extended {
             let mut my_extended = ExtendedHandshake::new();
+            my_extended.v = Some(ByteBuf(crate::client_name_and_version().as_bytes()));
             self.handler
                 .update_my_extended_handshake(&mut my_extended)?;
             let my_extended = Message::Extended(ExtendedMessage::Handshake(my_extended));
diff --git a/crates/librqbit_core/src/peer_id.rs b/crates/librqbit_core/src/peer_id.rs
index 3bf96ae..6f2ce60 100644
--- a/crates/librqbit_core/src/peer_id.rs
+++ b/crates/librqbit_core/src/peer_id.rs
@@ -5,6 +5,9 @@ pub enum AzureusStyleKind {
     Deluge,
     LibTorrent,
     Transmission,
+    QBittorrent,
+    UTorrent,
+    RQBit,
     Other([char; 2]),
 }
 
@@ -20,6 +23,9 @@ impl AzureusStyleKind {
             b"DE" => AzureusStyleKind::Deluge,
             b"lt" | b"LT" => AzureusStyleKind::LibTorrent,
             b"TR" => AzureusStyleKind::Transmission,
+            b"qB" => AzureusStyleKind::QBittorrent,
+            b"UT" => AzureusStyleKind::UTorrent,
+            b"rQ" => AzureusStyleKind::RQBit,
             _ => AzureusStyleKind::Other([b1 as char, b2 as char]),
         }
     }
@@ -53,7 +59,7 @@ pub fn generate_peer_id() -> Id20 {
     let u = uuid::Uuid::new_v4();
     peer_id[4..20].copy_from_slice(&u.as_bytes()[..]);
 
-    peer_id[..8].copy_from_slice(b"-rQ0001-");
+    peer_id[..8].copy_from_slice(b"-rQ7000-");
 
     Id20::new(peer_id)
 }
diff --git a/crates/peer_binary_protocol/src/extended/ut_pex.rs b/crates/peer_binary_protocol/src/extended/ut_pex.rs
index 73698f2..8e1b0a8 100644
--- a/crates/peer_binary_protocol/src/extended/ut_pex.rs
+++ b/crates/peer_binary_protocol/src/extended/ut_pex.rs
@@ -3,7 +3,6 @@ use std::net::{IpAddr, SocketAddr};
 use byteorder::{ByteOrder, BE};
 use bytes::Bytes;
 use clone_to_owned::CloneToOwned;
-use itertools::{EitherOrBoth, Itertools};
 use serde::{Deserialize, Serialize};
 
 pub struct PexPeerInfo {
@@ -23,16 +22,20 @@ impl core::fmt::Debug for PexPeerInfo {
 
 #[derive(Serialize, Default, Deserialize)]
 pub struct UtPex<B> {
-    added: B,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    added: Option<B>,
     #[serde(rename = "added.f")]
     #[serde(skip_serializing_if = "Option::is_none")]
     added_f: Option<B>,
-    added6: B,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    added6: Option<B>,
     #[serde(rename = "added6.f")]
     #[serde(skip_serializing_if = "Option::is_none")]
     added6_f: Option<B>,
-    dropped: B,
-    dropped6: B,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    dropped: Option<B>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    dropped6: Option<B>,
 }
 
 impl<B> core::fmt::Debug for UtPex<B>
@@ -79,28 +82,31 @@ where
 {
     fn added_peers_inner<'a>(
         &'a self,
-        buf: &'a B,
+        buf: &'a Option<B>,
         flags: &'a Option<B>,
         ip_len: usize,
     ) -> impl Iterator<Item = PexPeerInfo> + Clone + 'a {
-        let addrs = buf.as_ref().chunks_exact(ip_len + 2).map(move |c| {
-            let ip = match ip_len {
-                4 => IpAddr::from(TryInto::<[u8; 4]>::try_into(&c[..4]).unwrap()),
-                16 => IpAddr::from(TryInto::<[u8; 16]>::try_into(&c[..16]).unwrap()),
-                _ => unreachable!(),
-            };
-            let port = BE::read_u16(&c[ip_len..]);
-            SocketAddr::new(ip, port)
-        });
-        let flags = flags
+        const PORT_LEN: usize = 2;
+        const DEFAULT_FLAGS: u8 = 0;
+        let addrs = buf
             .as_ref()
-            .map(|b| b.as_ref().iter().copied())
             .into_iter()
-            .flatten();
-        addrs.zip_longest(flags).filter_map(|eob| match eob {
-            EitherOrBoth::Both(addr, flags) => Some(PexPeerInfo { flags, addr }),
-            EitherOrBoth::Left(addr) => Some(PexPeerInfo { flags: 0, addr }),
-            EitherOrBoth::Right(_) => None,
+            .flat_map(move |it| it.as_ref().chunks_exact(ip_len + PORT_LEN))
+            .map(move |c| {
+                let ip = match ip_len {
+                    4 => IpAddr::from(TryInto::<[u8; 4]>::try_into(&c[..4]).unwrap()),
+                    16 => IpAddr::from(TryInto::<[u8; 16]>::try_into(&c[..16]).unwrap()),
+                    _ => unreachable!(),
+                };
+                let port = BE::read_u16(&c[ip_len..]);
+                SocketAddr::new(ip, port)
+            });
+        addrs.enumerate().map(move |(id, addr)| PexPeerInfo {
+            addr,
+            flags: flags
+                .as_ref()
+                .and_then(|f| f.as_ref().get(id).copied())
+                .unwrap_or(DEFAULT_FLAGS),
         })
     }