From 970a0e9dab04835bcad41876abb1326c535ea735 Mon Sep 17 00:00:00 2001
From: Peng Hailin <unisko@gmail.com>
Date: Wed, 31 Aug 2016 09:01:59 +0800
Subject: [PATCH] update

---
 SUMMARY.md | 1 +
 1 file changed, 1 insertion(+)

diff --git a/SUMMARY.md b/SUMMARY.md
index 7c4817b..ff8b906 100644
--- a/SUMMARY.md
+++ b/SUMMARY.md
@@ -4,4 +4,5 @@
 * [第一章, 网络、线缆、OSI及TCP模型](d01-Networks-Cables-OSI-and-TCP-Models.md)
 * [第二章, CSMA/CD, 交换和虚拟局域网](d02-CSMA-CD-Switching-and-VLANs.md)
 * [第三章, 中继、DTP 及 VLAN 间路由](d03-Trunking-DTP-and-Inter-VLAN-Routing.md)
+* [第四章, 路由器和交换机安全](d04-Router-and-Switch-Security.md)