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       <nav id="sidebar" class="sidebar" aria-label="Table of contents">
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-          <ol class="chapter"><li class="chapter-item expanded affix "><a href="../index.html" class="active">60 天通过 CCNA 考试</a></li><li class="chapter-item expanded "><a href="d01-Networks-Cables-OSI-and-TCP-Models.html"><strong aria-hidden="true">1.</strong> 第1天, 网络、线缆、OSI及TCP模型</a></li><li class="chapter-item expanded "><a href="d02-CSMA-CD-Switching-and-VLANs.html"><strong aria-hidden="true">2.</strong> 第2天, CSMA/CD, 交换和虚拟局域网</a></li><li class="chapter-item expanded "><a href="d03-Trunking-DTP-and-Inter-VLAN-Routing.html"><strong aria-hidden="true">3.</strong> 第3天, 中继、DTP 及 VLAN 间路由</a></li><li class="chapter-item expanded "><a href="d04-Router-and-Switch-Security.html"><strong aria-hidden="true">4.</strong> 第4天, 路由器和交换机安全</a></li><li class="chapter-item expanded "><a href="d05-IP-Addressing.html"><strong aria-hidden="true">5.</strong> 第5天, IP 地址分配</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">进阶</li><li class="chapter-item expanded "><a href="d06-NAT.html"><strong aria-hidden="true">6.</strong> 第6天, 网络地址转换</a></li><li class="chapter-item expanded "><a href="d07-IPv6.html"><strong aria-hidden="true">7.</strong> 第7天, 互联网协议版本6</a></li><li class="chapter-item expanded "><a href="d08-Integrating-IPv4-and-IPv6-Network-Environments.html"><strong aria-hidden="true">8.</strong> 第8天, IPv4与IPv6共存的网络环境</a></li><li class="chapter-item expanded "><a href="d09-ACL.html"><strong aria-hidden="true">9.</strong> 第9天, 访问控制清单</a></li><li class="chapter-item expanded "><a href="d10-Routing-Concepts.html"><strong aria-hidden="true">10.</strong> 第10天, 路由的一些概念</a></li><li class="chapter-item expanded "><a href="d11-Static-Routing.html"><strong aria-hidden="true">11.</strong> 第11天, 静态路由</a></li><li class="chapter-item expanded "><a href="d12-OSPF-Basics.html"><strong aria-hidden="true">12.</strong> 第12天, OSPF基础知识</a></li><li class="chapter-item expanded "><a href="d13-OSPFv3.html"><strong aria-hidden="true">13.</strong> 第13天, OSPF版本3</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">实操</li><li class="chapter-item expanded "><a href="d14-DHCP-and-DNS.html"><strong aria-hidden="true">14.</strong> 第14天, DHCP及DNS</a></li><li class="chapter-item expanded "><a href="d15-Layer_1-and-Layer_2-Troubleshooting.html"><strong aria-hidden="true">15.</strong> 第15天, 一二层排错</a></li><li class="chapter-item expanded "><a href="d31-Spanning-Tree-Protocol.html"><strong aria-hidden="true">16.</strong> 第31天, 生成树协议</a></li><li class="chapter-item expanded "><a href="d32-Rapid-Spanning-Tree-Protocol.html"><strong aria-hidden="true">17.</strong> 第32天, 快速生成树协议</a></li><li class="chapter-item expanded "><a href="d33-EtherChannels-and-Link-Aggregation-Protocols.html"><strong aria-hidden="true">18.</strong> 第33天, 以太网通道及链路聚合协议</a></li><li class="chapter-item expanded "><a href="d34-First-Hop-Redundancy-Protocols.html"><strong aria-hidden="true">19.</strong> 第34天, 第一跳冗余协议</a></li><li class="chapter-item expanded "><a href="d35-booting-and-IOS.html"><strong aria-hidden="true">20.</strong> 第35天, 启动与IOS</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">EIGRP</li><li class="chapter-item expanded "><a href="d36-EIGRP.html"><strong aria-hidden="true">21.</strong> 第36天, EIGRP</a></li><li class="chapter-item expanded "><a href="d37-Rroubleshooting-EIGRP.html"><strong aria-hidden="true">22.</strong> 第37天，EIGRP故障排除</a></li><li class="chapter-item expanded "><a href="d38-EIGRP-For-IPv6.html"><strong aria-hidden="true">23.</strong> 第38天，IPv6下的EIGRP</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">OSPF</li><li class="chapter-item expanded "><a href="d39-OSPF.html"><strong aria-hidden="true">24.</strong> 第39天，开放最短路径优先协议</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">SNMP 与 NetFlow</li><li class="chapter-item expanded "><a href="d40-Syslog-SNMP-and-Netflow.html"><strong aria-hidden="true">25.</strong> 第40天，系统日志、简单网络管理协议与NetFlow软件</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">广域网 WAN</li><li class="chapter-item expanded "><a href="d41-Wide-Area-Networking.html"><strong aria-hidden="true">26.</strong> 第41天，广域组网</a></li><li class="chapter-item expanded "><a href="d42-Frame-Relay-and-PPP.html"><strong aria-hidden="true">27.</strong> 第42天，帧中继与点对点协议</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">附录</li><li class="chapter-item expanded "><a href="port-mirroring.html"><strong aria-hidden="true">28.</strong> 附录一：华为交换机端口镜像</a></li><li class="chapter-item expanded "><a href="IPv6_address_space.html"><strong aria-hidden="true">29.</strong> 附录二：IPv6地址空间</a></li><li class="chapter-item expanded "><a href="GNS3_tutorial.html"><strong aria-hidden="true">30.</strong> 附录三：GNS3简介</a></li></ol>
+          <ol class="chapter"><li class="chapter-item expanded affix "><a href="../index.html" class="active">60 天通过 CCNA 考试</a></li><li class="chapter-item expanded "><a href="d01-Networks-Cables-OSI-and-TCP-Models.html"><strong aria-hidden="true">1.</strong> 网络、线缆、OSI及TCP模型</a></li><li class="chapter-item expanded "><a href="d02-CSMA-CD-Switching-and-VLANs.html"><strong aria-hidden="true">2.</strong> CSMA/CD, 交换和虚拟局域网</a></li><li class="chapter-item expanded "><a href="d03-Trunking-DTP-and-Inter-VLAN-Routing.html"><strong aria-hidden="true">3.</strong> 中继、DTP 及 VLAN 间路由</a></li><li class="chapter-item expanded "><a href="d04-Router-and-Switch-Security.html"><strong aria-hidden="true">4.</strong> 路由器和交换机安全</a></li><li class="chapter-item expanded "><a href="d05-IP-Addressing.html"><strong aria-hidden="true">5.</strong> IP 地址分配</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">进阶</li><li class="chapter-item expanded "><a href="d06-NAT.html"><strong aria-hidden="true">6.</strong> 网络地址转换</a></li><li class="chapter-item expanded "><a href="d07-IPv6.html"><strong aria-hidden="true">7.</strong> 互联网协议版本6</a></li><li class="chapter-item expanded "><a href="d08-Integrating-IPv4-and-IPv6-Network-Environments.html"><strong aria-hidden="true">8.</strong> IPv4与IPv6共存的网络环境</a></li><li class="chapter-item expanded "><a href="d09-ACL.html"><strong aria-hidden="true">9.</strong> 访问控制清单</a></li><li class="chapter-item expanded "><a href="d10-Routing-Concepts.html"><strong aria-hidden="true">10.</strong> 路由的一些概念</a></li><li class="chapter-item expanded "><a href="d11-Static-Routing.html"><strong aria-hidden="true">11.</strong> 静态路由</a></li><li class="chapter-item expanded "><a href="d12-OSPF-Basics.html"><strong aria-hidden="true">12.</strong> OSPF基础知识</a></li><li class="chapter-item expanded "><a href="d13-OSPFv3.html"><strong aria-hidden="true">13.</strong> OSPF版本3</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">实操</li><li class="chapter-item expanded "><a href="d14-DHCP-and-DNS.html"><strong aria-hidden="true">14.</strong> DHCP及DNS</a></li><li class="chapter-item expanded "><a href="d15-Layer_1-and-Layer_2-Troubleshooting.html"><strong aria-hidden="true">15.</strong> 一二层排错</a></li><li class="chapter-item expanded "><a href="d31-Spanning-Tree-Protocol.html"><strong aria-hidden="true">16.</strong> 生成树协议</a></li><li class="chapter-item expanded "><a href="d32-Rapid-Spanning-Tree-Protocol.html"><strong aria-hidden="true">17.</strong> 快速生成树协议</a></li><li class="chapter-item expanded "><a href="d33-EtherChannels-and-Link-Aggregation-Protocols.html"><strong aria-hidden="true">18.</strong> 以太网通道及链路聚合协议</a></li><li class="chapter-item expanded "><a href="d34-First-Hop-Redundancy-Protocols.html"><strong aria-hidden="true">19.</strong> 第一跳冗余协议</a></li><li class="chapter-item expanded "><a href="d35-booting-and-IOS.html"><strong aria-hidden="true">20.</strong> 启动与IOS</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">EIGRP</li><li class="chapter-item expanded "><a href="d36-EIGRP.html"><strong aria-hidden="true">21.</strong> EIGRP</a></li><li class="chapter-item expanded "><a href="d37-Rroubleshooting-EIGRP.html"><strong aria-hidden="true">22.</strong> EIGRP故障排除</a></li><li class="chapter-item expanded "><a href="d38-EIGRP-For-IPv6.html"><strong aria-hidden="true">23.</strong> IPv6下的EIGRP</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">OSPF</li><li class="chapter-item expanded "><a href="d39-OSPF.html"><strong aria-hidden="true">24.</strong> 开放最短路径优先协议</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">SNMP 与 NetFlow</li><li class="chapter-item expanded "><a href="d40-Syslog-SNMP-and-Netflow.html"><strong aria-hidden="true">25.</strong> 系统日志、简单网络管理协议与NetFlow软件</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">广域网 WAN</li><li class="chapter-item expanded "><a href="d41-Wide-Area-Networking.html"><strong aria-hidden="true">26.</strong> 广域组网</a></li><li class="chapter-item expanded "><a href="d42-Frame-Relay-and-PPP.html"><strong aria-hidden="true">27.</strong> 帧中继与点对点协议</a></li><li class="spacer"></li><li class="chapter-item expanded affix "><li class="part-title">附录</li><li class="chapter-item expanded "><a href="port-mirroring.html"><strong aria-hidden="true">28.</strong> 附录一：华为交换机端口镜像</a></li><li class="chapter-item expanded "><a href="IPv6_address_space.html"><strong aria-hidden="true">29.</strong> 附录二：IPv6地址空间</a></li><li class="chapter-item expanded "><a href="GNS3_tutorial.html"><strong aria-hidden="true">30.</strong> 附录三：GNS3简介</a></li></ol>
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 <hr />
 <p><strong>推荐模拟器</strong></p>
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-    <img src="images/GNS3_logo.png" />
+    <img src="images/GNS3_logo.png" alt="GNS3 logo" />
 </p>
 <p align="center">
     <a href="https://www.gns3.com/software/download">GNS3 下载(Linux, Windows, MacOS)</a>, <a href="GNS3_tutorial.html">GNS3入门教程</a>
diff --git a/src/SUMMARY.md b/src/SUMMARY.md
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+++ b/src/SUMMARY.md
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 # CCNA60 天
 
 [60 天通过 CCNA 考试](../README.md)
-- [第1天, 网络、线缆、OSI及TCP模型](d01-Networks-Cables-OSI-and-TCP-Models.md)
-- [第2天, CSMA/CD, 交换和虚拟局域网](d02-CSMA-CD-Switching-and-VLANs.md)
-- [第3天, 中继、DTP 及 VLAN 间路由](d03-Trunking-DTP-and-Inter-VLAN-Routing.md)
-- [第4天, 路由器和交换机安全](d04-Router-and-Switch-Security.md)
-- [第5天, IP 地址分配](d05-IP-Addressing.md)
+- [网络、线缆、OSI及TCP模型](d01-Networks-Cables-OSI-and-TCP-Models.md)
+- [CSMA/CD, 交换和虚拟局域网](d02-CSMA-CD-Switching-and-VLANs.md)
+- [中继、DTP 及 VLAN 间路由](d03-Trunking-DTP-and-Inter-VLAN-Routing.md)
+- [路由器和交换机安全](d04-Router-and-Switch-Security.md)
+- [IP 地址分配](d05-IP-Addressing.md)
 
 ---
 
 # 进阶
 
 
-- [第6天, 网络地址转换](d06-NAT.md)
-- [第7天, 互联网协议版本6](d07-IPv6.md)
-- [第8天, IPv4与IPv6共存的网络环境](d08-Integrating-IPv4-and-IPv6-Network-Environments.md)
-- [第9天, 访问控制清单](d09-ACL.md)
-- [第10天, 路由的一些概念](d10-Routing-Concepts.md)
-- [第11天, 静态路由](d11-Static-Routing.md)
-- [第12天, OSPF基础知识](d12-OSPF-Basics.md)
-- [第13天, OSPF版本3](d13-OSPFv3.md)
+- [网络地址转换](d06-NAT.md)
+- [互联网协议版本6](d07-IPv6.md)
+- [IPv4与IPv6共存的网络环境](d08-Integrating-IPv4-and-IPv6-Network-Environments.md)
+- [访问控制清单](d09-ACL.md)
+- [路由的一些概念](d10-Routing-Concepts.md)
+- [静态路由](d11-Static-Routing.md)
+- [OSPF基础知识](d12-OSPF-Basics.md)
+- [OSPF版本3](d13-OSPFv3.md)
 
 ---
 
 # 实操
 
 
-- [第14天, DHCP及DNS](d14-DHCP-and-DNS.md)
-- [第15天, 一二层排错](d15-Layer_1-and-Layer_2-Troubleshooting.md)
-- [第31天, 生成树协议](d31-Spanning-Tree-Protocol.md)
-- [第32天, 快速生成树协议](d32-Rapid-Spanning-Tree-Protocol.md)
-- [第33天, 以太网通道及链路聚合协议](d33-EtherChannels-and-Link-Aggregation-Protocols.md)
-- [第34天, 第一跳冗余协议](d34-First-Hop-Redundancy-Protocols.md)
-- [第35天, 启动与IOS](d35-booting-and-IOS.md)
+- [DHCP及DNS](d14-DHCP-and-DNS.md)
+- [一二层排错](d15-Layer_1-and-Layer_2-Troubleshooting.md)
+- [生成树协议](d31-Spanning-Tree-Protocol.md)
+- [快速生成树协议](d32-Rapid-Spanning-Tree-Protocol.md)
+- [以太网通道及链路聚合协议](d33-EtherChannels-and-Link-Aggregation-Protocols.md)
+- [第一跳冗余协议](d34-First-Hop-Redundancy-Protocols.md)
+- [启动与IOS](d35-booting-and-IOS.md)
 
 ---
 
 # EIGRP
 
 
-- [第36天, EIGRP](d36-EIGRP.md)
-- [第37天，EIGRP故障排除](d37-Rroubleshooting-EIGRP.md)
-- [第38天，IPv6下的EIGRP](d38-EIGRP-For-IPv6.md)
+- [EIGRP](d36-EIGRP.md)
+- [EIGRP故障排除](d37-Rroubleshooting-EIGRP.md)
+- [IPv6下的EIGRP](d38-EIGRP-For-IPv6.md)
 
 ---
 
 # OSPF
 
 
-- [第39天，开放最短路径优先协议](d39-OSPF.md)
+- [开放最短路径优先协议](d39-OSPF.md)
 
 ---
 
 # SNMP 与 NetFlow
-- [第40天，系统日志、简单网络管理协议与NetFlow软件](d40-Syslog-SNMP-and-Netflow.md)
+- [系统日志、简单网络管理协议与NetFlow软件](d40-Syslog-SNMP-and-Netflow.md)
 
 ---
 
 # 广域网 WAN
 
 
-- [第41天，广域组网](d41-Wide-Area-Networking.md)
-- [第42天，帧中继与点对点协议](d42-Frame-Relay-and-PPP.md)
+- [广域组网](d41-Wide-Area-Networking.md)
+- [帧中继与点对点协议](d42-Frame-Relay-and-PPP.md)
 
 ---