diff --git a/udp2raw-openvpn-config-guide.md b/udp2raw-openvpn-config-guide.md
index 14df2d5..86d294a 100644
--- a/udp2raw-openvpn-config-guide.md
+++ b/udp2raw-openvpn-config-guide.md
@@ -103,4 +103,7 @@ Check this article,its same for udp2raw+OpenVPN :
 https://github.com/wangyu-/UDPspeeder/wiki/UDPspeeder-openvpn-config-guide
 
 #### Note
-If you want to transparently redirect traffic by VPN, it's very important to add a route exception (on client side) so that the VPN won't hijack udp2raw's traffic. Since your VPN traffic goes throught udp2raw, if your VPN hijacks udp2raw's traffic then there will be a traffic loop and your udp2raw will lost connection.
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+If you want to transparently redirect traffic by VPN, it's very important to add a route exception (on client side) so that the VPN won't hijack udp2raw's traffic. Since your VPN traffic goes throught udp2raw, if your VPN hijacks udp2raw's traffic then there will be a traffic loop and your udp2raw will lost connection.
+
+#### Note2 
+for the reason of a smaller MTU see https://github.com/wangyu-/udp2raw/wiki/about-mtu
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