diff --git a/easytier/src/common/global_ctx.rs b/easytier/src/common/global_ctx.rs
index 5e9ed3c4..69c4f17b 100644
--- a/easytier/src/common/global_ctx.rs
+++ b/easytier/src/common/global_ctx.rs
@@ -1,5 +1,5 @@
use std::{
- collections::{HashMap, hash_map::DefaultHasher},
+ collections::{BTreeSet, HashMap, hash_map::DefaultHasher},
hash::Hasher,
net::{IpAddr, SocketAddr},
sync::{Arc, Mutex},
@@ -203,6 +203,7 @@ pub struct GlobalCtx {
cached_ipv4: AtomicCell