Packet Tracer 5.3是一款非常不错的Cisco(思科)网络设备模拟器，利用Packet Tracer 5.3练习思科IOS操作命令很不错的。对于想考思科初级认证(如CCNA)的朋友们来说，Packet Tracer 5.3是非常不错的选择。
支持VPN等部分安全试验！
支持3层交换 开始支持CCNP的BGP
可模拟思科路由器、交换机等设备CCNA阶段的全部实验
Cisco Networking Academy is pleased to announce the release of Cisco Packet Tracer version 5.3, a minor release that includes the following new protocol support and enhanced functionality:
更多新特性：
* Improved Linksys models, added WEP wireless security algorithm, Cable and DSL enhancements
* Call Manager Express (VOIP support)
* FTP server and routers/switches – server and client
* Email system (SMTP and POP3) – server and client
* Border Gateway Protocol (BGP) – limited implementation that allows for a more realistic representation of the Internet for scenarios
* Generic IP end devices – to create more versatility in device creation
* Activity Wizard Initial Tree enhancements – more scenario variations
The new protocol support and activity wizard enhancements in version 5.3 will enable instructors to teach concepts in CCNA Discovery, CCNA Exploration, and CCNP courses more effectively, including the following:
CCNA Discovery
* Networking for Home and Small Businesses: Improved Linksys models and wireless security protocols and algorithms, generic IP end devices
* Working at a Small-to-Medium Business or ISP: Better DNS, improved DHCP, wireless security, new FTP, SMTP, POP3
* Introducing Routing and Switching in the Enterprise: Improved multi-area OSPF, EIGRP, BGP
* Designing and Supporting Computer Networks: New VOIP, Call Manager Express
CCNA Exploration
* Network Fundamentals: Improved HTTP, DNS, DHCP; new FTP, SMTP, POP3
* Routing Protocols and Concepts: Improved multi-area OSPF, EIGRP, new BGP
* LAN Switching and Wireless: Improved Linksys models, wireless security algorithms, 802.11
* Accessing the WAN: New PPPoE, enhanced IPSec, Cable and DSL enhancements
CCNP
* Improved multiarea OSPF, EIGRP, new BGP
We recommend upgrading to the new version to take advantage of the many improvements included in this release. To learn more about how Packet Tracer can be used in each Networking Academy course, please view this new Packet Tracer 5.3 Curricula Support chart.
Packet Tracer 5.3 is currently available for download from the Packet Tracer resource pageon Academy Connection. To access this page, log in to Academy Connection and click the Cisco Packet Tracer graphic on the left of the page, select Software Downloads, then select the appropriate download package for your needs. The previous version of Packet Tracer, version 5.2.1.8, will continue to be available for download.
Packet Tracer 5.3 supports activities authored in Packet Tracer 5.0, 5.1, and 5.2.x. All activities included in IT Essentials: PC Hardware and Software, CCNA Discovery, CCNA Exploration, and CCNA Security are also fully compatible with Packet Tracer 5.3. Please note that activities authored or saved with Packet Tracer 5.3 can only be used with the version 5.3 software.
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下载地址:
无帮助文件的安装文件（较小）本人 下的就是这个！
https://www.sugarsync.com/pf/D874641_275821_29271
下载地址2：
有帮助文件的安装文件（较大）
https://www.sugarsync.com/pf/D874641_275821_29279
下载地址3：
http://hotfile.com/dl/40547663/974d1a5/PacketTracer53_setup.rar.html
其他下载地址：
http://hotfile.com/dl/40549184/2644bf6/PacketTracer53_(fedora)i386_installer-rpm.rar.html
http://hotfile.com/dl/40549555/ccb91cb/PacketTracer53_i386_installer-deb.rar.html
添加115网盘下载地址：http://u.115.com/file/f976fc36fc
