diff --git a/hosts/xlab-gateway/networking.nix b/hosts/xlab-gateway/networking.nix
index 043056b..f1c6ee1 100644
--- a/hosts/xlab-gateway/networking.nix
+++ b/hosts/xlab-gateway/networking.nix
@@ -55,7 +55,10 @@
         table inet mangle {
           chain postrouting {
             type filter hook postrouting priority filter; policy accept;
-            oifname "wg-*" tcp flags syn tcp option maxseg size set 1380
+            # oifname "wg-*" tcp flags syn tcp option maxseg size set 1380
+            # 完美替代 "clamp mss to pmtu"
+            # 它会自动计算：如果是 IPv4 流量设为 1380，IPv6 流量设为 1360
+            tcp flags syn tcp option maxseg size set rt mtu
           }
         }
       '';