diff --git a/easytier/proto/cli.proto b/easytier/proto/cli.proto
index 971002b..03bdba2 100644
--- a/easytier/proto/cli.proto
+++ b/easytier/proto/cli.proto
@@ -2,174 +2,171 @@ syntax = "proto3";
 package cli;
 
 message Status {
-    int32 code = 1;
-    string message = 2;
+  int32 code = 1;
+  string message = 2;
 }
 
 message PeerConnStats {
-    uint64 rx_bytes = 1;
-    uint64 tx_bytes = 2;
+  uint64 rx_bytes = 1;
+  uint64 tx_bytes = 2;
 
-    uint64 rx_packets = 3;
-    uint64 tx_packets = 4;
+  uint64 rx_packets = 3;
+  uint64 tx_packets = 4;
 
-    uint64 latency_us = 5;
+  uint64 latency_us = 5;
 }
 
 message TunnelInfo {
-    string tunnel_type = 1;
-    string local_addr = 2;
-    string remote_addr = 3;
+  string tunnel_type = 1;
+  string local_addr = 2;
+  string remote_addr = 3;
 }
 
 message PeerConnInfo {
-    string conn_id = 1;
-    uint32 my_peer_id = 2;
-    uint32 peer_id = 3;
-    repeated string features = 4;
-    TunnelInfo tunnel = 5;
-    PeerConnStats stats = 6;
-    float loss_rate = 7;
+  string conn_id = 1;
+  uint32 my_peer_id = 2;
+  uint32 peer_id = 3;
+  repeated string features = 4;
+  TunnelInfo tunnel = 5;
+  PeerConnStats stats = 6;
+  float loss_rate = 7;
 }
 
 message PeerInfo {
-    uint32 peer_id = 1;
-    repeated PeerConnInfo conns = 2;
+  uint32 peer_id = 1;
+  repeated PeerConnInfo conns = 2;
 }
 
 message ListPeerRequest {}
 
-message ListPeerResponse {
-    repeated PeerInfo peer_infos = 1;
-}
+message ListPeerResponse { repeated PeerInfo peer_infos = 1; }
 
 enum NatType {
-    // has NAT; but own a single public IP, port is not changed
-    Unknown = 0;
-    OpenInternet = 1;
-    NoPAT = 2;
-    FullCone = 3;
-    Restricted = 4;
-    PortRestricted = 5;
-    Symmetric = 6;
-    SymUdpFirewall = 7;
+  // has NAT; but own a single public IP, port is not changed
+  Unknown = 0;
+  OpenInternet = 1;
+  NoPAT = 2;
+  FullCone = 3;
+  Restricted = 4;
+  PortRestricted = 5;
+  Symmetric = 6;
+  SymUdpFirewall = 7;
 }
 
 message StunInfo {
-    NatType udp_nat_type = 1;
-    NatType tcp_nat_type = 2;
-    int64 last_update_time = 3;
-    repeated string public_ip = 4;
-    uint32 min_port = 5;
-    uint32 max_port = 6;
+  NatType udp_nat_type = 1;
+  NatType tcp_nat_type = 2;
+  int64 last_update_time = 3;
+  repeated string public_ip = 4;
+  uint32 min_port = 5;
+  uint32 max_port = 6;
 }
 
 message Route {
-    uint32 peer_id = 1;
-    string ipv4_addr = 2;
-    uint32 next_hop_peer_id = 3;
-    int32 cost = 4;
-    repeated string proxy_cidrs = 5;
-    string hostname = 6;
-    StunInfo stun_info = 7;
-    string inst_id = 8;
+  uint32 peer_id = 1;
+  string ipv4_addr = 2;
+  uint32 next_hop_peer_id = 3;
+  int32 cost = 4;
+  repeated string proxy_cidrs = 5;
+  string hostname = 6;
+  StunInfo stun_info = 7;
+  string inst_id = 8;
 }
 
 message ListRouteRequest {}
 
-message ListRouteResponse {
-    repeated Route routes = 1;
-}
+message ListRouteResponse { repeated Route routes = 1; }
+
+message DumpRouteRequest {}
+
+message DumpRouteResponse { string result = 1; }
 
 service PeerManageRpc {
-   rpc ListPeer (ListPeerRequest) returns (ListPeerResponse);
-   rpc ListRoute (ListRouteRequest) returns (ListRouteResponse);
+  rpc ListPeer(ListPeerRequest) returns (ListPeerResponse);
+  rpc ListRoute(ListRouteRequest) returns (ListRouteResponse);
+  rpc DumpRoute(DumpRouteRequest) returns (DumpRouteResponse);
 }
 
 enum ConnectorStatus {
-    CONNECTED = 0;
-    DISCONNECTED = 1;
-    CONNECTING = 2;
+  CONNECTED = 0;
+  DISCONNECTED = 1;
+  CONNECTING = 2;
 }
 
 message Connector {
-    string url = 1;
-    ConnectorStatus status = 2;
+  string url = 1;
+  ConnectorStatus status = 2;
 }
 
 message ListConnectorRequest {}
 
-message ListConnectorResponse {
-    repeated Connector connectors = 1;
-}
+message ListConnectorResponse { repeated Connector connectors = 1; }
 
 enum ConnectorManageAction {
-    ADD = 0;
-    REMOVE = 1;
+  ADD = 0;
+  REMOVE = 1;
 }
 
 message ManageConnectorRequest {
-    ConnectorManageAction action = 1;
-    string url = 2;
+  ConnectorManageAction action = 1;
+  string url = 2;
 }
 
-message ManageConnectorResponse { }
+message ManageConnectorResponse {}
 
 service ConnectorManageRpc {
-    rpc ListConnector (ListConnectorRequest) returns (ListConnectorResponse);
-    rpc ManageConnector (ManageConnectorRequest) returns (ManageConnectorResponse);
+  rpc ListConnector(ListConnectorRequest) returns (ListConnectorResponse);
+  rpc ManageConnector(ManageConnectorRequest) returns (ManageConnectorResponse);
 }
 
-message DirectConnectedPeerInfo {
-    int32 latency_ms = 1;
-}
+message DirectConnectedPeerInfo { int32 latency_ms = 1; }
 
 message PeerInfoForGlobalMap {
-    map<uint32, DirectConnectedPeerInfo> direct_peers = 1;
+  map<uint32, DirectConnectedPeerInfo> direct_peers = 1;
 }
 
 message GetGlobalPeerMapRequest {}
 
 message GetGlobalPeerMapResponse {
-    map<uint32, PeerInfoForGlobalMap> global_peer_map = 1;
+  map<uint32, PeerInfoForGlobalMap> global_peer_map = 1;
 }
 
 service PeerCenterRpc {
-    rpc GetGlobalPeerMap (GetGlobalPeerMapRequest) returns (GetGlobalPeerMapResponse);
+  rpc GetGlobalPeerMap(GetGlobalPeerMapRequest)
+      returns (GetGlobalPeerMapResponse);
 }
 
 message VpnPortalInfo {
-    string vpn_type = 1;
-    string client_config = 2;
-    repeated string connected_clients = 3;
+  string vpn_type = 1;
+  string client_config = 2;
+  repeated string connected_clients = 3;
 }
 
 message GetVpnPortalInfoRequest {}
-message GetVpnPortalInfoResponse {
-    VpnPortalInfo vpn_portal_info = 1;
-}
+message GetVpnPortalInfoResponse { VpnPortalInfo vpn_portal_info = 1; }
 
 service VpnPortalRpc {
-    rpc GetVpnPortalInfo (GetVpnPortalInfoRequest) returns (GetVpnPortalInfoResponse);
+  rpc GetVpnPortalInfo(GetVpnPortalInfoRequest)
+      returns (GetVpnPortalInfoResponse);
 }
 
 message HandshakeRequest {
-    uint32 magic = 1;
-    uint32 my_peer_id = 2;
-    uint32 version = 3;
-    repeated string features = 4;
-    string network_name = 5;
-    bytes network_secret_digrest = 6;
+  uint32 magic = 1;
+  uint32 my_peer_id = 2;
+  uint32 version = 3;
+  repeated string features = 4;
+  string network_name = 5;
+  bytes network_secret_digrest = 6;
 }
 
 message TaRpcPacket {
-    uint32 from_peer = 1;
-    uint32 to_peer = 2;
-    uint32 service_id = 3;
-    uint32 transact_id = 4;
-    bool is_req = 5;
-    bytes content = 6;
+  uint32 from_peer = 1;
+  uint32 to_peer = 2;
+  uint32 service_id = 3;
+  uint32 transact_id = 4;
+  bool is_req = 5;
+  bytes content = 6;
 
-    uint32 total_pieces = 7;
-    uint32 piece_idx = 8;
+  uint32 total_pieces = 7;
+  uint32 piece_idx = 8;
 }
diff --git a/easytier/src/easytier-cli.rs b/easytier/src/easytier-cli.rs
index f9f8365..bfcf96c 100644
--- a/easytier/src/easytier-cli.rs
+++ b/easytier/src/easytier-cli.rs
@@ -42,7 +42,7 @@ enum SubCommand {
     Peer(PeerArgs),
     Connector(ConnectorArgs),
     Stun,
-    Route,
+    Route(RouteArgs),
     PeerCenter,
     VpnPortal,
 }
@@ -72,6 +72,18 @@ enum PeerSubCommand {
     List(PeerListArgs),
 }
 
+#[derive(Args, Debug)]
+struct RouteArgs {
+    #[command(subcommand)]
+    sub_command: Option<RouteSubCommand>,
+}
+
+#[derive(Subcommand, Debug)]
+enum RouteSubCommand {
+    List,
+    Dump,
+}
+
 #[derive(Args, Debug)]
 struct ConnectorArgs {
     #[arg(short, long)]
@@ -204,6 +216,14 @@ impl CommandHandler {
         Ok(())
     }
 
+    async fn handle_route_dump(&self) -> Result<(), Error> {
+        let mut client = self.get_peer_manager_client().await?;
+        let request = tonic::Request::new(DumpRouteRequest::default());
+        let response = client.dump_route(request).await?;
+        println!("response: {}", response.into_inner().result);
+        Ok(())
+    }
+
     async fn handle_route_list(&self) -> Result<(), Error> {
         #[derive(tabled::Tabled)]
         struct RouteTableItem {
@@ -307,9 +327,10 @@ async fn main() -> Result<(), Error> {
                 handler.handle_connector_list().await?;
             }
         },
-        SubCommand::Route => {
-            handler.handle_route_list().await?;
-        }
+        SubCommand::Route(route_args) => match route_args.sub_command {
+            Some(RouteSubCommand::List) | None => handler.handle_route_list().await?,
+            Some(RouteSubCommand::Dump) => handler.handle_route_dump().await?,
+        },
         SubCommand::Stun => {
             timeout(Duration::from_secs(5), async move {
                 let collector = StunInfoCollector::new_with_default_servers();
diff --git a/easytier/src/peers/peer_manager.rs b/easytier/src/peers/peer_manager.rs
index 1a198b4..f10fba6 100644
--- a/easytier/src/peers/peer_manager.rs
+++ b/easytier/src/peers/peer_manager.rs
@@ -535,6 +535,10 @@ impl PeerManager {
         self.get_route().list_routes().await
     }
 
+    pub async fn dump_route(&self) -> String {
+        self.get_route().dump().await
+    }
+
     async fn run_nic_packet_process_pipeline(&self, data: &mut ZCPacket) {
         for pipeline in self.nic_packet_process_pipeline.read().await.iter().rev() {
             pipeline.try_process_packet_from_nic(data).await;
diff --git a/easytier/src/peers/peer_ospf_route.rs b/easytier/src/peers/peer_ospf_route.rs
index 7bde102..4222caf 100644
--- a/easytier/src/peers/peer_ospf_route.rs
+++ b/easytier/src/peers/peer_ospf_route.rs
@@ -700,9 +700,13 @@ impl Debug for PeerRouteServiceImpl {
     fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
         f.debug_struct("PeerRouteServiceImpl")
             .field("my_peer_id", &self.my_peer_id)
+            .field("sessions", &self.sessions)
+            .field("route_table", &self.route_table)
+            .field("route_table_with_cost", &self.route_table_with_cost)
+            .field("synced_route_info", &self.synced_route_info)
             .field(
-                "sessions",
-                &self.sessions.iter().map(|x| *x.key()).collect::<Vec<_>>(),
+                "cached_local_conn_map",
+                &self.cached_local_conn_map.lock().unwrap(),
             )
             .finish()
     }
@@ -842,9 +846,7 @@ impl PeerRouteServiceImpl {
 
         let all_peer_ids = &conn_bitmap.peer_ids;
         for (peer_idx, (peer_id, _)) in all_peer_ids.iter().enumerate() {
-            let Some(connected) = self.synced_route_info.conn_map.get(peer_id) else {
-                continue;
-            };
+            let connected = self.synced_route_info.conn_map.get(peer_id).unwrap();
 
             for (idx, (other_peer_id, _)) in all_peer_ids.iter().enumerate() {
                 if connected.0.contains(other_peer_id) {
@@ -942,7 +944,7 @@ impl PeerRouteServiceImpl {
         let my_peer_id = self.my_peer_id;
 
         let (peer_infos, conn_bitmap) = self.build_sync_request(&session);
-        tracing::trace!("my_id {:?}, pper_id: {:?}, peer_infos: {:?}, conn_bitmap: {:?}, synced_route_info: {:?} session: {:?}",
+        tracing::info!("my_id {:?}, pper_id: {:?}, peer_infos: {:?}, conn_bitmap: {:?}, synced_route_info: {:?} session: {:?}",
                        my_peer_id, dst_peer_id, peer_infos, conn_bitmap, self.synced_route_info, session);
 
         if peer_infos.is_none()
@@ -952,6 +954,10 @@ impl PeerRouteServiceImpl {
             return true;
         }
 
+        session
+            .need_sync_initiator_info
+            .store(false, Ordering::Relaxed);
+
         let ret = peer_rpc
             .do_client_rpc_scoped(SERVICE_ID, dst_peer_id, |c| async {
                 let client = RouteServiceClient::new(tarpc::client::Config::default(), c).spawn();
@@ -978,10 +984,6 @@ impl PeerRouteServiceImpl {
                     .dst_is_initiator
                     .store(ret.is_initiator, Ordering::Relaxed);
 
-                session
-                    .need_sync_initiator_info
-                    .store(false, Ordering::Relaxed);
-
                 session.update_dst_session_id(ret.session_id);
 
                 if let Some(peer_infos) = &peer_infos {
@@ -1014,6 +1016,22 @@ struct RouteSessionManager {
     sync_now_broadcast: tokio::sync::broadcast::Sender<()>,
 }
 
+impl Debug for RouteSessionManager {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("RouteSessionManager")
+            .field(
+                "session_tasks",
+                &self
+                    .session_tasks
+                    .iter()
+                    .map(|x| *x.key())
+                    .collect::<Vec<_>>(),
+            )
+            .field("dump_sessions", &self.dump_sessions())
+            .finish()
+    }
+}
+
 #[tarpc::server]
 impl RouteService for RouteSessionManager {
     async fn sync_route_info(
@@ -1052,7 +1070,7 @@ impl RouteService for RouteSessionManager {
 
         service_impl.update_route_table_and_cached_local_conn_bitmap();
 
-        tracing::debug!(
+        tracing::info!(
             "sync_route_info: from_peer_id: {:?}, is_initiator: {:?}, peer_infos: {:?}, conn_bitmap: {:?}, synced_route_info: {:?} session: {:?}, new_route_table: {:?}",
             from_peer_id, is_initiator, peer_infos, conn_bitmap, service_impl.synced_route_info, session, service_impl.route_table);
 
@@ -1297,6 +1315,16 @@ pub struct PeerRoute {
     tasks: std::sync::Mutex<JoinSet<()>>,
 }
 
+impl Debug for PeerRoute {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        f.debug_struct("PeerRoute")
+            .field("my_peer_id", &self.my_peer_id)
+            .field("service_impl", &self.service_impl)
+            .field("session_mgr", &self.session_mgr)
+            .finish()
+    }
+}
+
 impl PeerRoute {
     pub fn new(
         my_peer_id: PeerId,
@@ -1322,6 +1350,8 @@ impl PeerRoute {
         loop {
             tokio::time::sleep(Duration::from_secs(60)).await;
             service_impl.clear_expired_peer();
+            // TODO: use debug log level for this.
+            tracing::info!(?service_impl, "clear_expired_peer");
         }
     }
 
@@ -1449,6 +1479,10 @@ impl Route for PeerRoute {
         *self.service_impl.cost_calculator.lock().unwrap() = Some(_cost_fn);
         self.service_impl.update_route_table();
     }
+
+    async fn dump(&self) -> String {
+        format!("{:#?}", self)
+    }
 }
 
 impl PeerPacketFilter for Arc<PeerRoute> {}
diff --git a/easytier/src/peers/route_trait.rs b/easytier/src/peers/route_trait.rs
index ad64df3..aec6cad 100644
--- a/easytier/src/peers/route_trait.rs
+++ b/easytier/src/peers/route_trait.rs
@@ -78,6 +78,10 @@ pub trait Route {
     }
 
     async fn set_route_cost_fn(&self, _cost_fn: RouteCostCalculator) {}
+
+    async fn dump(&self) -> String {
+        "this route implementation does not support dump".to_string()
+    }
 }
 
 pub type ArcRoute = Arc<Box<dyn Route + Send + Sync>>;
diff --git a/easytier/src/peers/rpc_service.rs b/easytier/src/peers/rpc_service.rs
index 2f76384..2323e34 100644
--- a/easytier/src/peers/rpc_service.rs
+++ b/easytier/src/peers/rpc_service.rs
@@ -1,9 +1,8 @@
 use std::sync::Arc;
 
 use crate::rpc::{
-    cli::PeerInfo,
-    peer_manage_rpc_server::PeerManageRpc,
-    {ListPeerRequest, ListPeerResponse, ListRouteRequest, ListRouteResponse},
+    cli::PeerInfo, peer_manage_rpc_server::PeerManageRpc, DumpRouteRequest, DumpRouteResponse,
+    ListPeerRequest, ListPeerResponse, ListRouteRequest, ListRouteResponse,
 };
 use tonic::{Request, Response, Status};
 
@@ -60,4 +59,13 @@ impl PeerManageRpc for PeerManagerRpcService {
         reply.routes = self.peer_manager.list_routes().await;
         Ok(Response::new(reply))
     }
+
+    async fn dump_route(
+        &self,
+        _request: Request<DumpRouteRequest>, // Accept request of type HelloRequest
+    ) -> Result<Response<DumpRouteResponse>, Status> {
+        let mut reply = DumpRouteResponse::default();
+        reply.result = self.peer_manager.dump_route().await;
+        Ok(Response::new(reply))
+    }
 }