Add lazy P2P demand tracking and need_p2p override (#2003)

- add lazy_p2p so nodes only start background P2P for peers that actually have recent business traffic
- add need_p2p so specific peers can still request eager background P2P even when other nodes enable lazy mode
- cover the new behavior with focused connector/peer-manager tests plus three-node integration tests that verify relay-to-direct route transition

easytier-web/frontend-lib/src/components/Config.vue

@@ -93,10 +93,12 @@ const bool_flags: BoolFlag[] = [
   { field: 'disable_quic_input', help: 'disable_quic_input_help' },
   { field: 'disable_p2p', help: 'disable_p2p_help' },
   { field: 'p2p_only', help: 'p2p_only_help' },
+  { field: 'lazy_p2p', help: 'lazy_p2p_help' },
   { field: 'bind_device', help: 'bind_device_help' },
   { field: 'no_tun', help: 'no_tun_help' },
   { field: 'enable_exit_node', help: 'enable_exit_node_help' },
   { field: 'relay_all_peer_rpc', help: 'relay_all_peer_rpc_help' },
+  { field: 'need_p2p', help: 'need_p2p_help' },
   { field: 'multi_thread', help: 'multi_thread_help' },
   { field: 'proxy_forward_by_system', help: 'proxy_forward_by_system_help' },
   { field: 'disable_encryption', help: 'disable_encryption_help' },

easytier-web/frontend-lib/src/locales/cn.yaml

@@ -113,6 +113,9 @@ disable_p2p_help: 禁用 P2P 模式，所有流量通过手动指定的服务器
 p2p_only: 仅 P2P
 p2p_only_help: 仅与已经建立P2P连接的对等节点通信，不通过其他节点中转。
 
+lazy_p2p: 延迟 P2P
+lazy_p2p_help: 仅在实际流量需要某个对等节点时才尝试建立 P2P。开启 need-p2p 的节点仍会被主动连接。
+
 bind_device: 仅使用物理网卡
 bind_device_help: 仅使用物理网卡，避免 EasyTier 通过其他虚拟网建立连接。
 
@@ -127,6 +130,9 @@ relay_all_peer_rpc_help: |
   允许转发所有对等节点的RPC数据包，即使对等节点不在转发网络白名单中。
   这可以帮助白名单外网络中的对等节点建立P2P连接。
 
+need_p2p: 需要 P2P
+need_p2p_help: 即使其他节点启用了 lazy p2p，也要求它们主动与当前节点建立 P2P 连接。
+
 multi_thread: 启用多线程
 multi_thread_help: 使用多线程运行时
 

easytier-web/frontend-lib/src/locales/en.yaml

@@ -112,6 +112,9 @@ disable_p2p_help: Disable P2P mode; route all traffic through a manually specifi
 p2p_only: P2P Only
 p2p_only_help: Only communicate with peers that have already established P2P connections, do not relay through other nodes.
 
+lazy_p2p: Lazy P2P
+lazy_p2p_help: Only try to establish P2P when traffic actually targets a peer. Peers with need-p2p enabled are still connected proactively.
+
 bind_device: Bind to Physical Device Only
 bind_device_help: Use only the physical network interface to prevent EasyTier from connecting via virtual networks.
 
@@ -126,6 +129,9 @@ relay_all_peer_rpc_help: |
   Relay all peer rpc packets, even if the peer is not in the relay network whitelist.
   This can help peers not in relay network whitelist to establish p2p connection.
 
+need_p2p: Need P2P
+need_p2p_help: Ask other peers to proactively establish P2P connections to this node even when they enable lazy P2P.
+
 multi_thread: Multi Thread
 multi_thread_help: Use multi-thread runtime
 

easytier-web/frontend-lib/src/types/network.ts

@@ -53,10 +53,12 @@ export interface NetworkConfig {
   disable_quic_input?: boolean
   disable_p2p?: boolean
   p2p_only?: boolean
+  lazy_p2p?: boolean
   bind_device?: boolean
   no_tun?: boolean
   enable_exit_node?: boolean
   relay_all_peer_rpc?: boolean
+  need_p2p?: boolean
   multi_thread?: boolean
   proxy_forward_by_system?: boolean
   disable_encryption?: boolean
@@ -125,10 +127,12 @@ export function DEFAULT_NETWORK_CONFIG(): NetworkConfig {
     disable_quic_input: false,
     disable_p2p: false,
     p2p_only: false,
+    lazy_p2p: false,
     bind_device: true,
     no_tun: false,
     enable_exit_node: false,
     relay_all_peer_rpc: false,
+    need_p2p: false,
     multi_thread: true,
     proxy_forward_by_system: false,
     disable_encryption: false,

easytier/locales/app.yml

@@ -157,6 +157,12 @@ core_clap:
   p2p_only:
     en: "only communicate with peers that already establish p2p connection"
     zh-CN: "仅与已经建立P2P连接的对等节点通信"
+  lazy_p2p:
+    en: "only try to establish p2p when traffic actually needs the peer; peers marked as need-p2p are still connected proactively"
+    zh-CN: "仅在实际流量需要某个对等节点时才尝试建立P2P；被标记为 need-p2p 的节点仍会主动建立连接"
+  need_p2p:
+    en: "announce that other peers should proactively establish p2p connections to this node even when they enable lazy-p2p"
+    zh-CN: "声明即使其他节点启用了 lazy-p2p，也应主动与当前节点建立P2P连接"
   disable_tcp_hole_punching:
     en: "disable tcp hole punching"
     zh-CN: "禁用TCP打洞功能"

easytier/src/common/config.rs

@@ -40,6 +40,7 @@ pub fn gen_default_flags() -> Flags {
         relay_network_whitelist: "*".to_string(),
         disable_p2p: false,
         p2p_only: false,
+        lazy_p2p: false,
         relay_all_peer_rpc: false,
         disable_tcp_hole_punching: false,
         disable_udp_hole_punching: false,
@@ -63,6 +64,7 @@ pub fn gen_default_flags() -> Flags {
         tld_dns_zone: DEFAULT_ET_DNS_ZONE.to_string(),
 
         quic_listen_port: u32::MAX,
+        need_p2p: false,
     }
 }
 

easytier/src/common/global_ctx.rs

@@ -202,10 +202,7 @@ pub struct GlobalCtx {
 
     running_listeners: Mutex<Vec<url::Url>>,
 
-    enable_exit_node: bool,
-    proxy_forward_by_system: bool,
-    no_tun: bool,
-    p2p_only: bool,
+    flags: ArcSwap<Flags>,
 
     feature_flags: AtomicCell<PeerFeatureFlag>,
 
@@ -237,6 +234,17 @@ impl std::fmt::Debug for GlobalCtx {
 pub type ArcGlobalCtx = std::sync::Arc<GlobalCtx>;
 
 impl GlobalCtx {
+    fn derive_feature_flags(flags: &Flags, current: Option<PeerFeatureFlag>) -> PeerFeatureFlag {
+        let mut feature_flags = current.unwrap_or_default();
+        feature_flags.kcp_input = !flags.disable_kcp_input;
+        feature_flags.no_relay_kcp = flags.disable_relay_kcp;
+        feature_flags.support_conn_list_sync = true;
+        feature_flags.quic_input = !flags.disable_quic_input;
+        feature_flags.no_relay_quic = flags.disable_relay_quic;
+        feature_flags.need_p2p = flags.need_p2p;
+        feature_flags
+    }
+
     pub fn new(config_fs: impl ConfigLoader + 'static) -> Self {
         let id = config_fs.get_id();
         let network = config_fs.get_network_identity();
@@ -261,19 +269,9 @@ impl GlobalCtx {
 
         let stun_info_collector = Arc::new(stun_info_collector);
 
-        let enable_exit_node = config_fs.get_flags().enable_exit_node || cfg!(target_env = "ohos");
-        let proxy_forward_by_system = config_fs.get_flags().proxy_forward_by_system;
-        let no_tun = config_fs.get_flags().no_tun;
-        let p2p_only = config_fs.get_flags().p2p_only;
+        let flags = config_fs.get_flags();
 
-        let feature_flags = PeerFeatureFlag {
-            kcp_input: !config_fs.get_flags().disable_kcp_input,
-            no_relay_kcp: config_fs.get_flags().disable_relay_kcp,
-            support_conn_list_sync: true, // Enable selective peer list sync by default
-            quic_input: !config_fs.get_flags().disable_quic_input,
-            no_relay_quic: config_fs.get_flags().disable_relay_quic,
-            ..Default::default()
-        };
+        let feature_flags = Self::derive_feature_flags(&flags, None);
 
         let credential_storage_path = config_fs.get_credential_file();
         let credential_manager = Arc::new(CredentialManager::new(credential_storage_path));
@@ -301,10 +299,7 @@ impl GlobalCtx {
 
             running_listeners: Mutex::new(Vec::new()),
 
-            enable_exit_node,
-            proxy_forward_by_system,
-            no_tun,
-            p2p_only,
+            flags: ArcSwap::new(Arc::new(flags)),
 
             feature_flags: AtomicCell::new(feature_flags),
 
@@ -455,11 +450,20 @@ impl GlobalCtx {
     }
 
     pub fn get_flags(&self) -> Flags {
-        self.config.get_flags()
+        self.flags.load().as_ref().clone()
     }
 
     pub fn set_flags(&self, flags: Flags) {
-        self.config.set_flags(flags);
+        self.config.set_flags(flags.clone());
+        self.feature_flags.store(Self::derive_feature_flags(
+            &flags,
+            Some(self.feature_flags.load()),
+        ));
+        self.flags.store(Arc::new(flags));
+    }
+
+    pub fn flags_arc(&self) -> Arc<Flags> {
+        self.flags.load_full()
     }
 
     pub fn get_128_key(&self) -> [u8; 16] {
@@ -503,15 +507,15 @@ impl GlobalCtx {
     }
 
     pub fn enable_exit_node(&self) -> bool {
-        self.enable_exit_node
+        self.flags.load().enable_exit_node || cfg!(target_env = "ohos")
     }
 
     pub fn proxy_forward_by_system(&self) -> bool {
-        self.proxy_forward_by_system
+        self.flags.load().proxy_forward_by_system
     }
 
     pub fn no_tun(&self) -> bool {
-        self.no_tun
+        self.flags.load().no_tun
     }
 
     pub fn get_feature_flags(&self) -> PeerFeatureFlag {
@@ -611,12 +615,13 @@ impl GlobalCtx {
     }
 
     pub fn p2p_only(&self) -> bool {
-        self.p2p_only
+        self.flags.load().p2p_only
     }
 
     pub fn latency_first(&self) -> bool {
         // NOTICE: p2p only is conflict with latency first
-        self.config.get_flags().latency_first && !self.p2p_only
+        let flags = self.flags.load();
+        flags.latency_first && !flags.p2p_only
     }
 
     fn is_port_in_running_listeners(&self, port: u16, is_udp: bool) -> bool {
@@ -730,6 +735,35 @@ pub mod tests {
         ));
     }
 
+    #[tokio::test]
+    async fn set_flags_keeps_derived_feature_flags_in_sync() {
+        let config = TomlConfigLoader::default();
+        let global_ctx = GlobalCtx::new(config);
+
+        let mut feature_flags = global_ctx.get_feature_flags();
+        feature_flags.avoid_relay_data = true;
+        feature_flags.is_public_server = true;
+        global_ctx.set_feature_flags(feature_flags);
+
+        let mut flags = global_ctx.get_flags();
+        flags.disable_kcp_input = true;
+        flags.disable_relay_kcp = true;
+        flags.disable_quic_input = true;
+        flags.disable_relay_quic = true;
+        flags.need_p2p = true;
+        global_ctx.set_flags(flags);
+
+        let feature_flags = global_ctx.get_feature_flags();
+        assert!(!feature_flags.kcp_input);
+        assert!(feature_flags.no_relay_kcp);
+        assert!(!feature_flags.quic_input);
+        assert!(feature_flags.no_relay_quic);
+        assert!(feature_flags.need_p2p);
+        assert!(feature_flags.support_conn_list_sync);
+        assert!(feature_flags.avoid_relay_data);
+        assert!(feature_flags.is_public_server);
+    }
+
     pub fn get_mock_global_ctx_with_network(
         network_identy: Option<NetworkIdentity>,
     ) -> ArcGlobalCtx {

easytier/src/connector/direct.rs

@@ -8,7 +8,7 @@ use std::{
         atomic::{AtomicBool, Ordering},
         Arc,
     },
-    time::Duration,
+    time::{Duration, Instant},
 };
 
 use crate::{
@@ -40,7 +40,10 @@ use rand::Rng;
 use tokio::{net::UdpSocket, task::JoinSet, time::timeout};
 use url::Host;
 
-use super::{create_connector_by_url, udp_hole_punch};
+use super::{
+    create_connector_by_url, should_background_p2p_with_peer, should_try_p2p_with_peer,
+    udp_hole_punch,
+};
 
 pub const DIRECT_CONNECTOR_SERVICE_ID: u32 = 1;
 pub const DIRECT_CONNECTOR_BLACKLIST_TIMEOUT_SEC: u64 = 300;
@@ -58,14 +61,22 @@ impl PeerManagerForDirectConnector for PeerManager {
     async fn list_peers(&self) -> Vec<PeerId> {
         let mut ret = vec![];
         let allow_public_server = use_global_var!(DIRECT_CONNECT_TO_PUBLIC_SERVER);
+        let lazy_p2p = self.get_global_ctx().get_flags().lazy_p2p;
+        let now = Instant::now();
 
         let routes = self.list_routes().await;
-        for r in routes.iter().filter(|r| {
-            r.feature_flag
-                .map(|r| allow_public_server || !r.is_public_server)
-                .unwrap_or(true)
-        }) {
-            ret.push(r.peer_id);
+        for route in routes.iter() {
+            let static_allowed = should_background_p2p_with_peer(
+                route.feature_flag.as_ref(),
+                allow_public_server,
+                lazy_p2p,
+            );
+            let dynamic_allowed =
+                should_try_p2p_with_peer(route.feature_flag.as_ref(), allow_public_server)
+                    && self.has_recent_traffic(route.peer_id, now);
+            if static_allowed || dynamic_allowed {
+                ret.push(route.peer_id);
+            }
         }
 
         ret
@@ -625,7 +636,11 @@ impl DirectConnectorManager {
             global_ctx.clone(),
             peer_manager.clone(),
         ));
-        let client = PeerTaskManager::new(DirectConnectorLauncher(data.clone()), peer_manager);
+        let client = PeerTaskManager::new_with_external_signal(
+            DirectConnectorLauncher(data.clone()),
+            peer_manager.clone(),
+            Some(peer_manager.p2p_demand_notify()),
+        );
         Self {
             global_ctx,
             data,
@@ -696,7 +711,7 @@ mod tests {
 
         let mut f = p_a.get_global_ctx().get_flags();
         f.bind_device = false;
-        p_a.get_global_ctx().config.set_flags(f);
+        p_a.get_global_ctx().set_flags(f);
 
         p_c.get_global_ctx()
             .config
@@ -765,7 +780,7 @@ mod tests {
         }
         let mut f = p_c.get_global_ctx().config.get_flags();
         f.enable_ipv6 = ipv6;
-        p_c.get_global_ctx().config.set_flags(f);
+        p_c.get_global_ctx().set_flags(f);
         let mut lis_c = ListenerManager::new(p_c.get_global_ctx(), p_c.clone());
         lis_c.prepare_listeners().await.unwrap();
 

easytier/src/connector/http_connector.rs

@@ -334,7 +334,7 @@ mod tests {
 
         let mut flags = global_ctx.config.get_flags();
         flags.bind_device = false;
-        global_ctx.config.set_flags(flags);
+        global_ctx.set_flags(flags);
         let mut connector = HttpTunnelConnector::new(test_url.clone(), global_ctx.clone());
 
         let mut listener = TcpTunnelListener::new("tcp://0.0.0.0:25888".parse().unwrap());

easytier/src/connector/mod.rs

@@ -15,6 +15,7 @@ use crate::tunnel::unix::UnixSocketTunnelConnector;
 use crate::tunnel::wireguard::{WgConfig, WgTunnelConnector};
 use crate::{
     common::{error::Error, global_ctx::ArcGlobalCtx, idn, network::IPCollector},
+    proto::common::PeerFeatureFlag,
     tunnel::{
         check_scheme_and_get_socket_addr, ring::RingTunnelConnector, tcp::TcpTunnelConnector,
         udp::UdpTunnelConnector, IpVersion, TunnelConnector,
@@ -29,6 +30,24 @@ pub mod udp_hole_punch;
 pub mod dns_connector;
 pub mod http_connector;
 
+pub(crate) fn should_try_p2p_with_peer(
+    feature_flag: Option<&PeerFeatureFlag>,
+    allow_public_server: bool,
+) -> bool {
+    feature_flag
+        .map(|flag| allow_public_server || !flag.is_public_server)
+        .unwrap_or(true)
+}
+
+pub(crate) fn should_background_p2p_with_peer(
+    feature_flag: Option<&PeerFeatureFlag>,
+    allow_public_server: bool,
+    lazy_p2p: bool,
+) -> bool {
+    should_try_p2p_with_peer(feature_flag, allow_public_server)
+        && (!lazy_p2p || feature_flag.map(|flag| flag.need_p2p).unwrap_or(false))
+}
+
 async fn set_bind_addr_for_peer_connector(
     connector: &mut (impl TunnelConnector + ?Sized),
     is_ipv4: bool,
@@ -197,3 +216,59 @@ pub async fn create_connector_by_url(
 
     Ok(connector)
 }
+
+#[cfg(test)]
+mod tests {
+    use crate::proto::common::PeerFeatureFlag;
+
+    use super::{should_background_p2p_with_peer, should_try_p2p_with_peer};
+
+    #[test]
+    fn lazy_background_p2p_requires_need_p2p() {
+        let no_need_p2p = PeerFeatureFlag {
+            need_p2p: false,
+            ..Default::default()
+        };
+        let need_p2p = PeerFeatureFlag {
+            need_p2p: true,
+            ..Default::default()
+        };
+
+        assert!(should_background_p2p_with_peer(
+            Some(&no_need_p2p),
+            false,
+            false
+        ));
+        assert!(!should_background_p2p_with_peer(
+            Some(&no_need_p2p),
+            false,
+            true
+        ));
+        assert!(should_background_p2p_with_peer(
+            Some(&need_p2p),
+            false,
+            true
+        ));
+    }
+
+    #[test]
+    fn p2p_policy_respects_public_server_setting() {
+        let public_server = PeerFeatureFlag {
+            is_public_server: true,
+            ..Default::default()
+        };
+
+        assert!(!should_try_p2p_with_peer(Some(&public_server), false));
+        assert!(should_try_p2p_with_peer(Some(&public_server), true));
+        assert!(!should_background_p2p_with_peer(
+            Some(&public_server),
+            false,
+            false
+        ));
+        assert!(should_background_p2p_with_peer(
+            Some(&public_server),
+            true,
+            false
+        ));
+    }
+}

easytier/src/connector/tcp_hole_punch.rs

@@ -1,7 +1,7 @@
 use std::{
     net::{IpAddr, Ipv4Addr, Ipv6Addr, SocketAddr},
     sync::Arc,
-    time::Duration,
+    time::{Duration, Instant},
 };
 
 use anyhow::{Context, Error};
@@ -29,6 +29,8 @@ use crate::{
     },
 };
 
+use crate::connector::{should_background_p2p_with_peer, should_try_p2p_with_peer};
+
 pub const BLACKLIST_TIMEOUT_SEC: u64 = 3600;
 
 fn handle_rpc_result<T>(
@@ -418,6 +420,7 @@ impl PeerTaskLauncher for TcpHolePunchPeerTaskLauncher {
     #[tracing::instrument(skip(self, data))]
     async fn collect_peers_need_task(&self, data: &Self::Data) -> Vec<Self::CollectPeerItem> {
         let global_ctx = data.peer_mgr.get_global_ctx();
+        let lazy_p2p = global_ctx.get_flags().lazy_p2p;
         let my_tcp_nat_type = NatType::try_from(
             global_ctx
                 .get_stun_info_collector()
@@ -434,16 +437,17 @@ impl PeerTaskLauncher for TcpHolePunchPeerTaskLauncher {
         }
 
         let my_peer_id = data.peer_mgr.my_peer_id();
+        let now = Instant::now();
 
         data.blacklist.cleanup();
 
         let mut peers_to_connect = Vec::new();
         for route in data.peer_mgr.list_routes().await.iter() {
-            if route
-                .feature_flag
-                .map(|x| x.is_public_server)
-                .unwrap_or(false)
-            {
+            let static_allowed =
+                should_background_p2p_with_peer(route.feature_flag.as_ref(), false, lazy_p2p);
+            let dynamic_allowed = should_try_p2p_with_peer(route.feature_flag.as_ref(), false)
+                && data.peer_mgr.has_recent_traffic(route.peer_id, now);
+            if !static_allowed && !dynamic_allowed {
                 continue;
             }
 
@@ -520,7 +524,11 @@ impl TcpHolePunchConnector {
     pub fn new(peer_mgr: Arc<PeerManager>) -> Self {
         Self {
             server: TcpHolePunchServer::new(peer_mgr.clone()),
-            client: PeerTaskManager::new(TcpHolePunchPeerTaskLauncher {}, peer_mgr.clone()),
+            client: PeerTaskManager::new_with_external_signal(
+                TcpHolePunchPeerTaskLauncher {},
+                peer_mgr.clone(),
+                Some(peer_mgr.p2p_demand_notify()),
+            ),
             peer_mgr,
         }
     }
@@ -570,12 +578,15 @@ mod tests {
         connector::tcp_hole_punch::TcpHolePunchConnector,
         peers::{
             peer_manager::PeerManager,
+            peer_task::PeerTaskLauncher,
             tests::{connect_peer_manager, create_mock_peer_manager, wait_route_appear},
         },
         proto::common::{NatType, StunInfo},
         tunnel::common::tests::wait_for_condition,
     };
 
+    use super::TcpHolePunchPeerTaskLauncher;
+
     struct MockStunInfoCollector {
         udp_nat_type: NatType,
         tcp_nat_type: NatType,
@@ -619,6 +630,17 @@ mod tests {
             .replace_stun_info_collector(collector);
     }
 
+    async fn collect_lazy_punch_peers(peer_mgr: Arc<PeerManager>) -> Vec<u32> {
+        let launcher = TcpHolePunchPeerTaskLauncher {};
+        let data = launcher.new_data(peer_mgr);
+        launcher
+            .collect_peers_need_task(&data)
+            .await
+            .into_iter()
+            .map(|task| task.dst_peer_id)
+            .collect()
+    }
+
     #[tokio::test]
     async fn tcp_hole_punch_connects() {
         let p_a = create_mock_peer_manager().await;
@@ -701,4 +723,33 @@ mod tests {
             .map(|c| c.is_empty())
             .unwrap_or(true));
     }
+
+    #[tokio::test]
+    async fn lazy_p2p_collects_tcp_hole_punch_tasks_only_after_recent_traffic() {
+        let p_a = create_mock_peer_manager().await;
+        let p_b = create_mock_peer_manager().await;
+        let p_c = create_mock_peer_manager().await;
+
+        replace_stun_info_collector(p_a.clone(), NatType::PortRestricted);
+        replace_stun_info_collector(p_b.clone(), NatType::PortRestricted);
+        replace_stun_info_collector(p_c.clone(), NatType::PortRestricted);
+
+        let mut flags = p_a.get_global_ctx().get_flags();
+        flags.lazy_p2p = true;
+        p_a.get_global_ctx().set_flags(flags);
+
+        connect_peer_manager(p_a.clone(), p_b.clone()).await;
+        connect_peer_manager(p_b.clone(), p_c.clone()).await;
+        wait_route_appear(p_a.clone(), p_c.clone()).await.unwrap();
+
+        assert!(!collect_lazy_punch_peers(p_a.clone())
+            .await
+            .contains(&p_c.my_peer_id()));
+
+        p_a.mark_recent_traffic(p_c.my_peer_id());
+
+        assert!(collect_lazy_punch_peers(p_a.clone())
+            .await
+            .contains(&p_c.my_peer_id()));
+    }
 }

easytier/src/connector/udp_hole_punch/mod.rs

@@ -1,6 +1,6 @@
 use std::{
     sync::{atomic::AtomicBool, Arc},
-    time::Duration,
+    time::{Duration, Instant},
 };
 
 use anyhow::{Context, Error};
@@ -32,6 +32,8 @@ use crate::{
     tunnel::Tunnel,
 };
 
+use crate::connector::{should_background_p2p_with_peer, should_try_p2p_with_peer};
+
 pub(crate) mod both_easy_sym;
 pub(crate) mod common;
 pub(crate) mod cone;
@@ -426,6 +428,8 @@ impl PeerTaskLauncher for UdpHolePunchPeerTaskLauncher {
         }
 
         let my_peer_id = data.peer_mgr.my_peer_id();
+        let lazy_p2p = data.peer_mgr.get_global_ctx().get_flags().lazy_p2p;
+        let now = Instant::now();
 
         data.blacklist.cleanup();
 
@@ -434,11 +438,11 @@ impl PeerTaskLauncher for UdpHolePunchPeerTaskLauncher {
         // 2. peers is full cone (any restricted type);
         // 3. peers not in blacklist;
         for route in data.peer_mgr.list_routes().await.iter() {
-            if route
-                .feature_flag
-                .map(|x| x.is_public_server)
-                .unwrap_or(false)
-            {
+            let static_allowed =
+                should_background_p2p_with_peer(route.feature_flag.as_ref(), false, lazy_p2p);
+            let dynamic_allowed = should_try_p2p_with_peer(route.feature_flag.as_ref(), false)
+                && data.peer_mgr.has_recent_traffic(route.peer_id, now);
+            if !static_allowed && !dynamic_allowed {
                 continue;
             }
 
@@ -531,7 +535,11 @@ impl UdpHolePunchConnector {
     pub fn new(peer_mgr: Arc<PeerManager>) -> Self {
         Self {
             server: UdpHolePunchServer::new(peer_mgr.clone()),
-            client: PeerTaskManager::new(UdpHolePunchPeerTaskLauncher {}, peer_mgr.clone()),
+            client: PeerTaskManager::new_with_external_signal(
+                UdpHolePunchPeerTaskLauncher {},
+                peer_mgr.clone(),
+                Some(peer_mgr.p2p_demand_notify()),
+            ),
             peer_mgr,
         }
     }
@@ -580,12 +588,13 @@ pub mod tests {
     use crate::common::stun::MockStunInfoCollector;
     use crate::peers::{
         peer_manager::PeerManager,
+        peer_task::PeerTaskLauncher,
         tests::{connect_peer_manager, create_mock_peer_manager, wait_route_appear},
     };
     use crate::proto::common::NatType;
     use crate::tunnel::common::tests::wait_for_condition;
 
-    use super::{UdpHolePunchConnector, RUN_TESTING};
+    use super::{UdpHolePunchConnector, UdpHolePunchPeerTaskLauncher, RUN_TESTING};
 
     pub fn replace_stun_info_collector(peer_mgr: Arc<PeerManager>, udp_nat_type: NatType) {
         let collector = Box::new(MockStunInfoCollector { udp_nat_type });
@@ -602,6 +611,17 @@ pub mod tests {
         p_a
     }
 
+    async fn collect_lazy_punch_peers(peer_mgr: Arc<PeerManager>) -> Vec<u32> {
+        let launcher = UdpHolePunchPeerTaskLauncher {};
+        let data = launcher.new_data(peer_mgr);
+        launcher
+            .collect_peers_need_task(&data)
+            .await
+            .into_iter()
+            .map(|task| task.dst_peer_id)
+            .collect()
+    }
+
     #[rstest::rstest]
     #[tokio::test]
     pub async fn test_hole_punching_blacklist(
@@ -634,4 +654,29 @@ pub mod tests {
         )
         .await;
     }
+
+    #[tokio::test]
+    async fn lazy_p2p_collects_udp_hole_punch_tasks_only_after_recent_traffic() {
+        let p_a = create_mock_peer_manager_with_mock_stun(NatType::PortRestricted).await;
+        let p_b = create_mock_peer_manager_with_mock_stun(NatType::PortRestricted).await;
+        let p_c = create_mock_peer_manager_with_mock_stun(NatType::PortRestricted).await;
+
+        let mut flags = p_a.get_global_ctx().get_flags();
+        flags.lazy_p2p = true;
+        p_a.get_global_ctx().set_flags(flags);
+
+        connect_peer_manager(p_a.clone(), p_b.clone()).await;
+        connect_peer_manager(p_b.clone(), p_c.clone()).await;
+        wait_route_appear(p_a.clone(), p_c.clone()).await.unwrap();
+
+        assert!(!collect_lazy_punch_peers(p_a.clone())
+            .await
+            .contains(&p_c.my_peer_id()));
+
+        p_a.mark_recent_traffic(p_c.my_peer_id());
+
+        assert!(collect_lazy_punch_peers(p_a.clone())
+            .await
+            .contains(&p_c.my_peer_id()));
+    }
 }

easytier/src/core.rs

@@ -404,6 +404,15 @@ struct NetworkOptions {
     )]
     p2p_only: Option<bool>,
 
+    #[arg(
+        long,
+        env = "ET_LAZY_P2P",
+        help = t!("core_clap.lazy_p2p").to_string(),
+        num_args = 0..=1,
+        default_missing_value = "true"
+    )]
+    lazy_p2p: Option<bool>,
+
     #[arg(
         long,
         env = "ET_DISABLE_P2P",
@@ -449,6 +458,15 @@ struct NetworkOptions {
     )]
     relay_all_peer_rpc: Option<bool>,
 
+    #[arg(
+        long,
+        env = "ET_NEED_P2P",
+        help = t!("core_clap.need_p2p").to_string(),
+        num_args = 0..=1,
+        default_missing_value = "true"
+    )]
+    need_p2p: Option<bool>,
+
     #[cfg(feature = "socks5")]
     #[arg(
         long,
@@ -1012,6 +1030,7 @@ impl NetworkOptions {
         }
         f.disable_p2p = self.disable_p2p.unwrap_or(f.disable_p2p);
         f.p2p_only = self.p2p_only.unwrap_or(f.p2p_only);
+        f.lazy_p2p = self.lazy_p2p.unwrap_or(f.lazy_p2p);
         f.disable_tcp_hole_punching = self
             .disable_tcp_hole_punching
             .unwrap_or(f.disable_tcp_hole_punching);
@@ -1019,6 +1038,7 @@ impl NetworkOptions {
             .disable_udp_hole_punching
             .unwrap_or(f.disable_udp_hole_punching);
         f.relay_all_peer_rpc = self.relay_all_peer_rpc.unwrap_or(f.relay_all_peer_rpc);
+        f.need_p2p = self.need_p2p.unwrap_or(f.need_p2p);
         f.multi_thread = self.multi_thread.unwrap_or(f.multi_thread);
         if let Some(compression) = &self.compression {
             f.data_compress_algo = match compression.as_str() {

easytier/src/instance/dns_server/tests.rs

@@ -45,7 +45,7 @@ pub async fn prepare_env_with_tld_dns_zone(
         if let Some(zone) = tld_dns_zone {
             flags.tld_dns_zone = zone.to_string();
         }
-        ctx.config.set_flags(flags);
+        ctx.set_flags(flags);
     }
 
     let (s, r) = create_packet_recv_chan();

easytier/src/instance/instance.rs

@@ -593,9 +593,12 @@ impl Instance {
         let mut direct_conn_manager =
             DirectConnectorManager::new(global_ctx.clone(), peer_manager.clone());
         direct_conn_manager.run();
+        let direct_conn_manager = Arc::new(direct_conn_manager);
 
-        let udp_hole_puncher = UdpHolePunchConnector::new(peer_manager.clone());
-        let tcp_hole_puncher = TcpHolePunchConnector::new(peer_manager.clone());
+        let udp_hole_puncher =
+            Arc::new(Mutex::new(UdpHolePunchConnector::new(peer_manager.clone())));
+        let tcp_hole_puncher =
+            Arc::new(Mutex::new(TcpHolePunchConnector::new(peer_manager.clone())));
 
         let peer_center = Arc::new(PeerCenterInstance::new(peer_manager.clone()));
 
@@ -618,9 +621,9 @@ impl Instance {
             peer_manager,
             listener_manager,
             conn_manager,
-            direct_conn_manager: Arc::new(direct_conn_manager),
-            udp_hole_puncher: Arc::new(Mutex::new(udp_hole_puncher)),
-            tcp_hole_puncher: Arc::new(Mutex::new(tcp_hole_puncher)),
+            direct_conn_manager,
+            udp_hole_puncher,
+            tcp_hole_puncher,
 
             ip_proxy: None,
             #[cfg(feature = "kcp")]

easytier/src/launcher.rs

@@ -762,6 +762,10 @@ impl NetworkConfig {
             flags.p2p_only = p2p_only;
         }
 
+        if let Some(lazy_p2p) = self.lazy_p2p {
+            flags.lazy_p2p = lazy_p2p;
+        }
+
         if let Some(bind_device) = self.bind_device {
             flags.bind_device = bind_device;
         }
@@ -778,6 +782,10 @@ impl NetworkConfig {
             flags.relay_all_peer_rpc = relay_all_peer_rpc;
         }
 
+        if let Some(need_p2p) = self.need_p2p {
+            flags.need_p2p = need_p2p;
+        }
+
         if let Some(multi_thread) = self.multi_thread {
             flags.multi_thread = multi_thread;
         }
@@ -956,10 +964,12 @@ impl NetworkConfig {
         result.disable_quic_input = Some(flags.disable_quic_input);
         result.disable_p2p = Some(flags.disable_p2p);
         result.p2p_only = Some(flags.p2p_only);
+        result.lazy_p2p = Some(flags.lazy_p2p);
         result.bind_device = Some(flags.bind_device);
         result.no_tun = Some(flags.no_tun);
         result.enable_exit_node = Some(flags.enable_exit_node);
         result.relay_all_peer_rpc = Some(flags.relay_all_peer_rpc);
+        result.need_p2p = Some(flags.need_p2p);
         result.multi_thread = Some(flags.multi_thread);
         result.proxy_forward_by_system = Some(flags.proxy_forward_by_system);
         result.disable_encryption = Some(!flags.enable_encryption);
@@ -1214,10 +1224,12 @@ mod tests {
                 flags.disable_quic_input = rng.gen_bool(0.3);
                 flags.disable_p2p = rng.gen_bool(0.2);
                 flags.p2p_only = rng.gen_bool(0.2);
+                flags.lazy_p2p = rng.gen_bool(0.3);
                 flags.bind_device = rng.gen_bool(0.3);
                 flags.no_tun = rng.gen_bool(0.1);
                 flags.enable_exit_node = rng.gen_bool(0.4);
                 flags.relay_all_peer_rpc = rng.gen_bool(0.5);
+                flags.need_p2p = rng.gen_bool(0.3);
                 flags.multi_thread = rng.gen_bool(0.7);
                 flags.proxy_forward_by_system = rng.gen_bool(0.3);
                 flags.enable_encryption = rng.gen_bool(0.8);

easytier/src/peers/foreign_network_manager.rs

@@ -1182,7 +1182,7 @@ pub mod tests {
         tracing::debug!("pm_center: {:?}", pm_center.my_peer_id());
         let mut flag = pm_center.get_global_ctx().get_flags();
         flag.relay_network_whitelist = ["net1".to_string(), "net2*".to_string()].join(" ");
-        pm_center.get_global_ctx().config.set_flags(flag);
+        pm_center.get_global_ctx().set_flags(flag);
 
         let pma_net1 = create_mock_peer_manager_for_foreign_network(name.as_str()).await;
 
@@ -1209,7 +1209,7 @@ pub mod tests {
         let mut flag = pm_center.get_global_ctx().get_flags();
         flag.relay_network_whitelist = "".to_string();
         flag.relay_all_peer_rpc = true;
-        pm_center.get_global_ctx().config.set_flags(flag);
+        pm_center.get_global_ctx().set_flags(flag);
         tracing::debug!("pm_center: {:?}", pm_center.my_peer_id());
 
         let pma_net1 = create_mock_peer_manager_for_foreign_network("net1").await;

easytier/src/peers/peer_manager.rs

@@ -2,7 +2,7 @@ use std::{
     fmt::Debug,
     net::{IpAddr, Ipv4Addr, Ipv6Addr},
     sync::{atomic::AtomicBool, Arc, Weak},
-    time::{Instant, SystemTime},
+    time::{Duration, Instant, SystemTime},
 };
 
 use anyhow::Context;
@@ -63,6 +63,7 @@ use super::{
     peer_map::PeerMap,
     peer_ospf_route::PeerRoute,
     peer_rpc::PeerRpcManager,
+    peer_task::ExternalTaskSignal,
     relay_peer_map::RelayPeerMap,
     route_trait::{ArcRoute, Route},
     BoxNicPacketFilter, BoxPeerPacketFilter, PacketRecvChan, PacketRecvChanReceiver,
@@ -161,6 +162,8 @@ pub struct PeerManager {
     exit_nodes: RwLock<Vec<IpAddr>>,
 
     reserved_my_peer_id_map: DashMap<String, PeerId>,
+    recent_have_traffic: Arc<DashMap<PeerId, Instant>>,
+    p2p_demand_notify: Arc<ExternalTaskSignal>,
 
     allow_loopback_tunnel: AtomicBool,
 
@@ -181,6 +184,39 @@ impl Debug for PeerManager {
 }
 
 impl PeerManager {
+    // Keep lazy-p2p demand alive across the 5s task rescan interval and a full on-demand
+    // connect attempt, without retaining extra per-task state in the hot path.
+    const RECENT_HAVE_TRAFFIC_TTL: Duration = Duration::from_secs(30);
+
+    fn should_mark_recent_traffic_for_fanout(total_dst_peers: usize) -> bool {
+        total_dst_peers <= 1
+    }
+
+    fn gc_recent_traffic_entries<F>(
+        recent_have_traffic: &DashMap<PeerId, Instant>,
+        now: Instant,
+        mut has_directly_connected_conn: F,
+    ) where
+        F: FnMut(PeerId) -> bool,
+    {
+        let mut to_remove = Vec::new();
+        for entry in recent_have_traffic.iter() {
+            let peer_id = *entry.key();
+            let expired =
+                now.saturating_duration_since(*entry.value()) > Self::RECENT_HAVE_TRAFFIC_TTL;
+            if expired || has_directly_connected_conn(peer_id) {
+                to_remove.push(peer_id);
+            }
+        }
+
+        if !to_remove.is_empty() {
+            for peer_id in to_remove {
+                recent_have_traffic.remove(&peer_id);
+            }
+            shrink_dashmap(recent_have_traffic, None);
+        }
+    }
+
     pub fn new(
         route_algo: RouteAlgoType,
         global_ctx: ArcGlobalCtx,
@@ -334,6 +370,8 @@ impl PeerManager {
             exit_nodes: RwLock::new(exit_nodes),
 
             reserved_my_peer_id_map: DashMap::new(),
+            recent_have_traffic: Arc::new(DashMap::new()),
+            p2p_demand_notify: Arc::new(ExternalTaskSignal::new()),
 
             allow_loopback_tunnel: AtomicBool::new(true),
 
@@ -349,6 +387,57 @@ impl PeerManager {
             .store(allow_loopback_tunnel, std::sync::atomic::Ordering::Relaxed);
     }
 
+    pub fn mark_recent_traffic(&self, dst_peer_id: PeerId) {
+        if dst_peer_id == self.my_peer_id {
+            return;
+        }
+
+        let flags = self.global_ctx.flags_arc();
+        if flags.disable_p2p || !flags.lazy_p2p || self.has_directly_connected_conn(dst_peer_id) {
+            return;
+        }
+
+        let now = Instant::now();
+        if let Some(mut last_seen) = self.recent_have_traffic.get_mut(&dst_peer_id) {
+            let should_notify =
+                now.saturating_duration_since(*last_seen) > Self::RECENT_HAVE_TRAFFIC_TTL;
+            *last_seen = now;
+            if !should_notify {
+                return;
+            }
+        } else {
+            self.recent_have_traffic.insert(dst_peer_id, now);
+        }
+        self.p2p_demand_notify.notify();
+    }
+
+    pub fn has_recent_traffic(&self, peer_id: PeerId, now: Instant) -> bool {
+        if self.has_directly_connected_conn(peer_id) {
+            return false;
+        }
+
+        self.recent_have_traffic
+            .get(&peer_id)
+            .map(|last_seen| {
+                now.saturating_duration_since(*last_seen) <= Self::RECENT_HAVE_TRAFFIC_TTL
+            })
+            .unwrap_or(false)
+    }
+
+    pub fn clear_recent_traffic(&self, peer_id: PeerId) {
+        self.recent_have_traffic.remove(&peer_id);
+    }
+
+    pub fn p2p_demand_notify(&self) -> Arc<ExternalTaskSignal> {
+        self.p2p_demand_notify.clone()
+    }
+
+    fn gc_recent_traffic(&self) {
+        Self::gc_recent_traffic_entries(&self.recent_have_traffic, Instant::now(), |peer_id| {
+            self.has_directly_connected_conn(peer_id)
+        });
+    }
+
     fn build_foreign_network_manager_accessor(
         peer_map: &Arc<PeerMap>,
     ) -> Box<dyn GlobalForeignNetworkAccessor> {
@@ -405,7 +494,9 @@ impl PeerManager {
                 "network identity not match".to_string(),
             ));
         }
+        let peer_id = peer_conn.get_peer_id();
         self.peers.add_new_peer_conn(peer_conn).await?;
+        self.clear_recent_traffic(peer_id);
         Ok(())
     }
 
@@ -1152,6 +1243,7 @@ impl PeerManager {
         mut msg: ZCPacket,
         dst_peer_id: PeerId,
     ) -> Result<(), Error> {
+        self.mark_recent_traffic(dst_peer_id);
         self.check_p2p_only_before_send(dst_peer_id)?;
 
         self.self_tx_counters
@@ -1229,19 +1321,32 @@ impl PeerManager {
         }
     }
 
-    pub async fn get_msg_dst_peer_ipv4(&self, ipv4_addr: &Ipv4Addr) -> (Vec<PeerId>, bool) {
-        let mut is_exit_node = false;
-        let mut dst_peers = vec![];
+    fn is_all_peers_broadcast_ipv4(&self, ipv4_addr: &Ipv4Addr) -> bool {
         let network_length = self
             .global_ctx
             .get_ipv4()
             .map(|x| x.network_length())
             .unwrap_or(24);
         let ipv4_inet = cidr::Ipv4Inet::new(*ipv4_addr, network_length).unwrap();
-        if ipv4_addr.is_broadcast()
+        ipv4_addr.is_broadcast()
             || ipv4_addr.is_multicast()
             || *ipv4_addr == ipv4_inet.last_address()
-        {
+    }
+
+    fn is_all_peers_broadcast_ipv6(&self, ipv6_addr: &Ipv6Addr) -> bool {
+        let network_length = self
+            .global_ctx
+            .get_ipv6()
+            .map(|x| x.network_length())
+            .unwrap_or(64);
+        let ipv6_inet = cidr::Ipv6Inet::new(*ipv6_addr, network_length).unwrap();
+        ipv6_addr.is_multicast() || *ipv6_addr == ipv6_inet.last_address()
+    }
+
+    pub async fn get_msg_dst_peer_ipv4(&self, ipv4_addr: &Ipv4Addr) -> (Vec<PeerId>, bool) {
+        let mut is_exit_node = false;
+        let mut dst_peers = vec![];
+        if self.is_all_peers_broadcast_ipv4(ipv4_addr) {
             dst_peers.extend(self.peers.list_routes().await.iter().filter_map(|x| {
                 if *x.key() != self.my_peer_id {
                     Some(*x.key())
@@ -1284,13 +1389,7 @@ impl PeerManager {
     pub async fn get_msg_dst_peer_ipv6(&self, ipv6_addr: &Ipv6Addr) -> (Vec<PeerId>, bool) {
         let mut is_exit_node = false;
         let mut dst_peers = vec![];
-        let network_length = self
-            .global_ctx
-            .get_ipv6()
-            .map(|x| x.network_length())
-            .unwrap_or(64);
-        let ipv6_inet = cidr::Ipv6Inet::new(*ipv6_addr, network_length).unwrap();
-        if ipv6_addr.is_multicast() || *ipv6_addr == ipv6_inet.last_address() {
+        if self.is_all_peers_broadcast_ipv6(ipv6_addr) {
             dst_peers.extend(self.peers.list_routes().await.iter().map(|x| *x.key()));
         } else if let Some(peer_id) = self.peers.get_peer_id_by_ipv6(ipv6_addr).await {
             dst_peers.push(peer_id);
@@ -1350,6 +1449,7 @@ impl PeerManager {
         }
         let cur_to_peer_id = msg.peer_manager_header().unwrap().to_peer_id.into();
         if cur_to_peer_id != 0 {
+            self.mark_recent_traffic(cur_to_peer_id);
             return Self::send_msg_internal(
                 &self.peers,
                 &self.foreign_network_client,
@@ -1395,7 +1495,12 @@ impl PeerManager {
         let mut errs: Vec<Error> = vec![];
         let mut msg = Some(msg);
         let total_dst_peers = dst_peers.len();
+        let should_mark_recent_traffic =
+            Self::should_mark_recent_traffic_for_fanout(total_dst_peers);
         for (i, peer_id) in dst_peers.iter().enumerate() {
+            if should_mark_recent_traffic {
+                self.mark_recent_traffic(*peer_id);
+            }
             if let Err(e) = self.check_p2p_only_before_send(*peer_id) {
                 errs.push(e);
                 continue;
@@ -1467,6 +1572,28 @@ impl PeerManager {
         });
     }
 
+    async fn run_recent_traffic_gc_routine(&self) {
+        let recent_have_traffic = self.recent_have_traffic.clone();
+        let peers = self.peers.clone();
+        let foreign_network_client = self.foreign_network_client.clone();
+        self.tasks.lock().await.spawn(async move {
+            loop {
+                PeerManager::gc_recent_traffic_entries(
+                    recent_have_traffic.as_ref(),
+                    Instant::now(),
+                    |peer_id| {
+                        if let Some(peer) = peers.get_peer_by_id(peer_id) {
+                            peer.has_directly_connected_conn()
+                        } else {
+                            foreign_network_client.get_peer_map().has_peer(peer_id)
+                        }
+                    },
+                );
+                tokio::time::sleep(std::time::Duration::from_secs(30)).await;
+            }
+        });
+    }
+
     async fn run_peer_session_gc_routine(&self) {
         let peer_session_store = self.peer_session_store.clone();
         self.tasks.lock().await.spawn(async move {
@@ -1499,6 +1626,7 @@ impl PeerManager {
         self.start_peer_recv().await;
         self.run_clean_peer_without_conn_routine().await;
         self.run_relay_session_gc_routine().await;
+        self.run_recent_traffic_gc_routine().await;
         self.run_peer_session_gc_routine().await;
 
         self.run_foriegn_network().await;
@@ -1729,7 +1857,11 @@ impl PeerManager {
 #[cfg(test)]
 mod tests {
 
-    use std::{fmt::Debug, sync::Arc, time::Duration};
+    use std::{
+        fmt::Debug,
+        sync::Arc,
+        time::{Duration, Instant},
+    };
 
     use crate::{
         common::{
@@ -1766,6 +1898,135 @@ mod tests {
 
     use super::PeerManager;
 
+    async fn create_lazy_peer_manager() -> Arc<PeerManager> {
+        let peer_mgr = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
+        let mut flags = peer_mgr.get_global_ctx().get_flags();
+        flags.lazy_p2p = true;
+        peer_mgr.get_global_ctx().set_flags(flags);
+        peer_mgr
+    }
+
+    #[test]
+    fn recent_traffic_fanout_policy_only_marks_single_peer() {
+        assert!(PeerManager::should_mark_recent_traffic_for_fanout(0));
+        assert!(PeerManager::should_mark_recent_traffic_for_fanout(1));
+        assert!(!PeerManager::should_mark_recent_traffic_for_fanout(2));
+    }
+
+    #[test]
+    fn gc_recent_traffic_removes_expired_and_connected_entries() {
+        let stale_peer = 1;
+        let direct_peer = 2;
+        let active_peer = 3;
+        let recent_have_traffic = dashmap::DashMap::new();
+
+        recent_have_traffic.insert(
+            stale_peer,
+            Instant::now() - PeerManager::RECENT_HAVE_TRAFFIC_TTL - Duration::from_millis(1),
+        );
+        recent_have_traffic.insert(direct_peer, Instant::now());
+        recent_have_traffic.insert(active_peer, Instant::now());
+
+        let future_peer = 4;
+
+        recent_have_traffic.insert(future_peer, Instant::now() + Duration::from_secs(1));
+
+        PeerManager::gc_recent_traffic_entries(&recent_have_traffic, Instant::now(), |peer_id| {
+            peer_id == direct_peer
+        });
+
+        assert!(!recent_have_traffic.contains_key(&stale_peer));
+        assert!(!recent_have_traffic.contains_key(&direct_peer));
+        assert!(recent_have_traffic.contains_key(&active_peer));
+        assert!(recent_have_traffic.contains_key(&future_peer));
+    }
+
+    #[tokio::test]
+    async fn recent_traffic_skips_direct_peers_and_clears_after_direct_connect() {
+        let peer_mgr_a = create_lazy_peer_manager().await;
+        let peer_mgr_b = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
+        let peer_b_id = peer_mgr_b.my_peer_id();
+
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+        assert!(peer_mgr_a.has_recent_traffic(peer_b_id, Instant::now()));
+
+        let (a_ring, b_ring) = create_ring_tunnel_pair();
+        let (client_ret, server_ret) = tokio::join!(
+            peer_mgr_a.add_client_tunnel(a_ring, true),
+            peer_mgr_b.add_tunnel_as_server(b_ring, true)
+        );
+        client_ret.unwrap();
+        server_ret.unwrap();
+
+        wait_for_condition(
+            || {
+                let peer_mgr_a = peer_mgr_a.clone();
+                async move { peer_mgr_a.has_directly_connected_conn(peer_b_id) }
+            },
+            Duration::from_secs(5),
+        )
+        .await;
+
+        wait_for_condition(
+            || {
+                let peer_mgr_a = peer_mgr_a.clone();
+                async move { !peer_mgr_a.has_recent_traffic(peer_b_id, Instant::now()) }
+            },
+            Duration::from_secs(5),
+        )
+        .await;
+
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+        assert!(
+            !peer_mgr_a.has_recent_traffic(peer_b_id, Instant::now()),
+            "directly connected peers should not be tracked as lazy-p2p demand"
+        );
+    }
+
+    #[tokio::test]
+    async fn recent_traffic_notifies_only_when_demand_becomes_active() {
+        let peer_mgr_a = create_lazy_peer_manager().await;
+        let peer_mgr_b = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
+        let peer_b_id = peer_mgr_b.my_peer_id();
+        let signal = peer_mgr_a.p2p_demand_notify();
+
+        let initial_version = signal.version();
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+        assert_eq!(signal.version(), initial_version + 1);
+
+        let first_seen = *peer_mgr_a.recent_have_traffic.get(&peer_b_id).unwrap();
+        tokio::time::sleep(Duration::from_millis(5)).await;
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+        assert_eq!(
+            signal.version(),
+            initial_version + 1,
+            "fresh demand should not wake all p2p workers again"
+        );
+        let refreshed_seen = *peer_mgr_a.recent_have_traffic.get(&peer_b_id).unwrap();
+        assert!(refreshed_seen > first_seen);
+
+        if let Some(mut last_seen) = peer_mgr_a.recent_have_traffic.get_mut(&peer_b_id) {
+            *last_seen =
+                Instant::now() - PeerManager::RECENT_HAVE_TRAFFIC_TTL - Duration::from_millis(1);
+        }
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+        assert_eq!(signal.version(), initial_version + 2);
+    }
+
+    #[tokio::test]
+    async fn recent_traffic_tolerates_future_timestamps() {
+        let peer_mgr_a = create_lazy_peer_manager().await;
+        let peer_mgr_b = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
+        let peer_b_id = peer_mgr_b.my_peer_id();
+
+        peer_mgr_a
+            .recent_have_traffic
+            .insert(peer_b_id, Instant::now() + Duration::from_secs(1));
+
+        assert!(peer_mgr_a.has_recent_traffic(peer_b_id, Instant::now()));
+        peer_mgr_a.mark_recent_traffic(peer_b_id);
+    }
+
     #[tokio::test]
     async fn drop_peer_manager() {
         let peer_mgr_a = create_mock_peer_manager_with_mock_stun(NatType::Unknown).await;
@@ -2175,7 +2436,7 @@ mod tests {
         let create_mgr = |enable_encryption| async move {
             let (s, _r) = create_packet_recv_chan();
             let mock_global_ctx = get_mock_global_ctx();
-            mock_global_ctx.config.set_flags(Flags {
+            mock_global_ctx.set_flags(Flags {
                 enable_encryption,
                 data_compress_algo: CompressionAlgoPb::Zstd.into(),
                 ..Default::default()

easytier/src/peers/peer_task.rs

@@ -1,5 +1,9 @@
-use std::result::Result;
-use std::sync::{Arc, Mutex};
+use std::{
+    result::Result,
+    sync::{atomic::Ordering, Arc, Mutex},
+};
+
+use atomic_shim::AtomicU64;
 
 use async_trait::async_trait;
 use dashmap::DashMap;
@@ -12,6 +16,39 @@ use anyhow::Error;
 
 use super::peer_manager::PeerManager;
 
+pub struct ExternalTaskSignal {
+    version: AtomicU64,
+    notify: Notify,
+}
+
+impl Default for ExternalTaskSignal {
+    fn default() -> Self {
+        Self::new()
+    }
+}
+
+impl ExternalTaskSignal {
+    pub fn new() -> Self {
+        Self {
+            version: AtomicU64::new(0),
+            notify: Notify::new(),
+        }
+    }
+
+    pub fn notify(&self) {
+        self.version.fetch_add(1, Ordering::Relaxed);
+        self.notify.notify_waiters();
+    }
+
+    pub fn version(&self) -> u64 {
+        self.version.load(Ordering::Relaxed)
+    }
+
+    pub fn notified(&self) -> impl std::future::Future<Output = ()> + '_ {
+        self.notify.notified()
+    }
+}
+
 #[async_trait]
 pub trait PeerTaskLauncher: Send + Sync + Clone + 'static {
     type Data;
@@ -35,9 +72,9 @@ pub trait PeerTaskLauncher: Send + Sync + Clone + 'static {
 
 pub struct PeerTaskManager<Launcher: PeerTaskLauncher> {
     launcher: Launcher,
-    peer_mgr: Arc<PeerManager>,
     main_loop_task: Mutex<Option<ScopedTask<()>>>,
     run_signal: Arc<Notify>,
+    external_signal: Option<Arc<ExternalTaskSignal>>,
     data: Launcher::Data,
 }
 
@@ -49,12 +86,20 @@ where
     L: PeerTaskLauncher<Data = D, CollectPeerItem = C, TaskRet = T> + 'static,
 {
     pub fn new(launcher: L, peer_mgr: Arc<PeerManager>) -> Self {
+        Self::new_with_external_signal(launcher, peer_mgr, None)
+    }
+
+    pub fn new_with_external_signal(
+        launcher: L,
+        peer_mgr: Arc<PeerManager>,
+        external_signal: Option<Arc<ExternalTaskSignal>>,
+    ) -> Self {
         let data = launcher.new_data(peer_mgr.clone());
         Self {
             launcher,
-            peer_mgr,
             main_loop_task: Mutex::new(None),
             run_signal: Arc::new(Notify::new()),
+            external_signal,
             data,
         }
     }
@@ -64,13 +109,20 @@ where
             self.launcher.clone(),
             self.data.clone(),
             self.run_signal.clone(),
+            self.external_signal.clone(),
         ))
         .into();
         self.main_loop_task.lock().unwrap().replace(task);
     }
 
-    async fn main_loop(launcher: L, data: D, signal: Arc<Notify>) {
+    async fn main_loop(
+        launcher: L,
+        data: D,
+        signal: Arc<Notify>,
+        external_signal: Option<Arc<ExternalTaskSignal>>,
+    ) {
         let peer_task_map = Arc::new(DashMap::<C, ScopedTask<Result<T, Error>>>::new());
+        let mut external_signal_version = external_signal.as_ref().map(|signal| signal.version());
 
         loop {
             let peers_to_connect = launcher.collect_peers_need_task(&data).await;
@@ -113,11 +165,31 @@ where
                 launcher.all_task_done(&data).await;
             }
 
-            select! {
-                _ = tokio::time::sleep(std::time::Duration::from_millis(
-                    launcher.loop_interval_ms(),
-                )) => {},
-                _ = signal.notified() => {}
+            if let Some(external_signal) = external_signal.as_ref() {
+                let notified = external_signal.notified();
+                tokio::pin!(notified);
+                let cur_version = external_signal.version();
+                if external_signal_version != Some(cur_version) {
+                    external_signal_version = Some(cur_version);
+                    continue;
+                }
+
+                select! {
+                    _ = tokio::time::sleep(std::time::Duration::from_millis(
+                        launcher.loop_interval_ms(),
+                    )) => {},
+                    _ = signal.notified() => {},
+                    _ = &mut notified => {
+                        external_signal_version = Some(external_signal.version());
+                    }
+                }
+            } else {
+                select! {
+                    _ = tokio::time::sleep(std::time::Duration::from_millis(
+                        launcher.loop_interval_ms(),
+                    )) => {},
+                    _ = signal.notified() => {}
+                }
             }
         }
     }

easytier/src/proto/api_manage.proto

@@ -85,6 +85,8 @@ message NetworkConfig {
   common.SecureModeConfig secure_mode = 55;
   reserved 56;
   optional string credential_file = 57;
+  optional bool lazy_p2p = 58;
+  optional bool need_p2p = 59;
 }
 
 message PortForwardConfig {

easytier/src/proto/common.proto

@@ -70,6 +70,9 @@ message FlagsInConfig {
   bool p2p_only = 32;
 
   bool disable_tcp_hole_punching = 34;
+
+  bool lazy_p2p = 37;
+  bool need_p2p = 38;
 }
 
 message RpcDescriptor {
@@ -217,6 +220,7 @@ message PeerFeatureFlag {
   bool quic_input = 6;
   bool no_relay_quic = 7;
   bool is_credential_peer = 8;
+  bool need_p2p = 9;
 }
 
 enum SocketType {

easytier/src/tests/three_node.rs

@@ -48,17 +48,20 @@ pub fn prepare_linux_namespaces() {
     del_netns("net_b");
     del_netns("net_c");
     del_netns("net_d");
+    del_netns("net_e");
 
     create_netns("net_a", "10.1.1.1/24", "fd11::1/64");
     create_netns("net_b", "10.1.1.2/24", "fd11::2/64");
     create_netns("net_c", "10.1.2.3/24", "fd12::3/64");
     create_netns("net_d", "10.1.2.4/24", "fd12::4/64");
+    create_netns("net_e", "10.1.1.3/24", "fd11::3/64");
 
     prepare_bridge("br_a");
     prepare_bridge("br_b");
 
     add_ns_to_bridge("br_a", "net_a");
     add_ns_to_bridge("br_a", "net_b");
+    add_ns_to_bridge("br_a", "net_e");
     add_ns_to_bridge("br_b", "net_c");
     add_ns_to_bridge("br_b", "net_d");
 }
@@ -89,10 +92,13 @@ pub async fn init_three_node(proto: &str) -> Vec<Instance> {
     init_three_node_ex(proto, |cfg| cfg, false).await
 }
 
-pub async fn init_three_node_ex<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
+async fn init_three_node_ex_with_inst3<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
     proto: &str,
     cfg_cb: F,
     use_public_server: bool,
+    inst3_ns: &str,
+    inst3_ipv4: &str,
+    inst3_ipv6: &str,
 ) -> Vec<Instance> {
     prepare_linux_namespaces();
 
@@ -110,9 +116,9 @@ pub async fn init_three_node_ex<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
     )));
     let mut inst3 = Instance::new(cfg_cb(get_inst_config(
         "inst3",
-        Some("net_c"),
-        "10.144.144.3",
-        "fd00::3/64",
+        Some(inst3_ns),
+        inst3_ipv4,
+        inst3_ipv6,
     )));
 
     inst1.run().await.unwrap();
@@ -211,6 +217,29 @@ pub async fn init_three_node_ex<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
     vec![inst1, inst2, inst3]
 }
 
+pub async fn init_three_node_ex<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
+    proto: &str,
+    cfg_cb: F,
+    use_public_server: bool,
+) -> Vec<Instance> {
+    init_three_node_ex_with_inst3(
+        proto,
+        cfg_cb,
+        use_public_server,
+        "net_c",
+        "10.144.144.3",
+        "fd00::3/64",
+    )
+    .await
+}
+
+async fn init_lazy_p2p_three_node_ex<F: Fn(TomlConfigLoader) -> TomlConfigLoader>(
+    proto: &str,
+    cfg_cb: F,
+) -> Vec<Instance> {
+    init_three_node_ex_with_inst3(proto, cfg_cb, false, "net_e", "10.144.144.3", "fd00::3/64").await
+}
+
 pub async fn drop_insts(insts: Vec<Instance>) {
     let mut set = JoinSet::new();
     for mut inst in insts {
@@ -2079,6 +2108,24 @@ where
     }
 }
 
+async fn wait_route_cost(inst: &Instance, peer_id: u32, cost: i32, timeout: Duration) {
+    let peer_manager = inst.get_peer_manager();
+    wait_for_condition(
+        move || {
+            let peer_manager = peer_manager.clone();
+            async move {
+                peer_manager
+                    .list_routes()
+                    .await
+                    .iter()
+                    .any(|route| route.peer_id == peer_id && route.cost == cost)
+            }
+        },
+        timeout,
+    )
+    .await;
+}
+
 #[rstest::rstest]
 #[tokio::test]
 #[serial_test::serial]
@@ -2400,6 +2447,124 @@ pub async fn acl_group_base_test(
     drop_insts(insts).await;
 }
 
+#[tokio::test]
+#[serial_test::serial]
+pub async fn lazy_p2p_builds_direct_connection_on_demand() {
+    let insts = init_lazy_p2p_three_node_ex("udp", |cfg| {
+        if cfg.get_inst_name() == "inst1" {
+            let mut flags = cfg.get_flags();
+            flags.lazy_p2p = true;
+            cfg.set_flags(flags);
+        }
+        cfg
+    })
+    .await;
+
+    let inst3_peer_id = insts[2].peer_id();
+    assert!(
+        !insts[0]
+            .get_peer_manager()
+            .get_peer_map()
+            .has_peer(inst3_peer_id),
+        "inst1 should not proactively connect to inst3 when lazy_p2p is enabled"
+    );
+    wait_route_cost(&insts[0], inst3_peer_id, 2, Duration::from_secs(5)).await;
+
+    assert!(
+        ping_test("net_a", "10.144.144.3", None).await,
+        "initial relay traffic should still succeed"
+    );
+
+    wait_for_condition(
+        || async {
+            insts[0]
+                .get_peer_manager()
+                .get_peer_map()
+                .has_peer(inst3_peer_id)
+        },
+        Duration::from_secs(10),
+    )
+    .await;
+    wait_route_cost(&insts[0], inst3_peer_id, 1, Duration::from_secs(10)).await;
+
+    drop_insts(insts).await;
+}
+
+#[tokio::test]
+#[serial_test::serial]
+pub async fn need_p2p_overrides_lazy_p2p() {
+    let insts = init_lazy_p2p_three_node_ex("udp", |cfg| {
+        let mut flags = cfg.get_flags();
+        if cfg.get_inst_name() == "inst1" {
+            flags.lazy_p2p = true;
+        }
+        if cfg.get_inst_name() == "inst3" {
+            flags.need_p2p = true;
+        }
+        cfg.set_flags(flags);
+        cfg
+    })
+    .await;
+
+    let inst3_peer_id = insts[2].peer_id();
+    wait_route_cost(&insts[0], inst3_peer_id, 2, Duration::from_secs(5)).await;
+    wait_for_condition(
+        || async {
+            insts[0]
+                .get_peer_manager()
+                .get_peer_map()
+                .has_peer(inst3_peer_id)
+        },
+        Duration::from_secs(10),
+    )
+    .await;
+    wait_route_cost(&insts[0], inst3_peer_id, 1, Duration::from_secs(10)).await;
+
+    drop_insts(insts).await;
+}
+
+#[tokio::test]
+#[serial_test::serial]
+pub async fn lazy_p2p_warms_up_before_p2p_only_send() {
+    let insts = init_lazy_p2p_three_node_ex("udp", |cfg| {
+        if cfg.get_inst_name() == "inst1" {
+            let mut flags = cfg.get_flags();
+            flags.lazy_p2p = true;
+            flags.p2p_only = true;
+            cfg.set_flags(flags);
+        }
+        cfg
+    })
+    .await;
+
+    let inst3_peer_id = insts[2].peer_id();
+    wait_route_cost(&insts[0], inst3_peer_id, 2, Duration::from_secs(5)).await;
+    assert!(
+        !ping_test("net_a", "10.144.144.3", None).await,
+        "the first send should still fail under p2p_only before direct connectivity exists"
+    );
+
+    wait_for_condition(
+        || async {
+            insts[0]
+                .get_peer_manager()
+                .get_peer_map()
+                .has_peer(inst3_peer_id)
+        },
+        Duration::from_secs(10),
+    )
+    .await;
+    wait_route_cost(&insts[0], inst3_peer_id, 1, Duration::from_secs(10)).await;
+
+    wait_for_condition(
+        || async { ping_test("net_a", "10.144.144.3", None).await },
+        Duration::from_secs(6),
+    )
+    .await;
+
+    drop_insts(insts).await;
+}
+
 #[rstest::rstest]
 #[tokio::test]
 #[serial_test::serial]