26/09/2014
Cisco WS-C2950G-48-EI
Once upon a time, this is a very start story of a CCNA exam preparation. Too early to tell them all but I am keen to take it apart – the ultimate destroyer would agree with me.
I do love Electronic Engineering, given that I had involved in quite a few of programming and Mechatronic projects. I am planning to study CCNA with attending ICND 1 and ICND 2 exams, which are the requirements to be qualified as an IT Engineer so I grabbed this Cisco switch.
Overall, C2950G gets a impressive built quality as well as the price. I wish I could get C3550 which is a L3 switch. Unfortunately, the seller on eBay informed me they were oversold the product but let me ‘upgrade’ to a lower level of the model for free(Yes, C2950 is not as good as 3550 but this one comes with more expensive EI version, stands for Enhanced Image) and I wanna give it a go.
I have got this switch for couple of days but I was quite busy so I made a decision to write this report on Saturday.
Now let’s have a look at the Cisco C2950 Switch with Enhanced Image firmware.
The C2950 is not as big as the 2821 router, with only half size of the router.
If we remove the screw on the back side and the rack, we can easily remove the top panel.
There are 2 large Broadcom chip with a Cisco logo on it. I cannot find much of the information (only says “24-PORT GBE SWITCH WITH 4-PORT GBE/2.5GBE HGL PORTS” on a few of websites) on the Internet so it most likely the special model manufactured for Cisco, and it is called BCM5628. I used a USB port to make a comparison with its size.
The PSU looks fairly simple but it must be reliable and durable. All of the capacitors were built in a very good quality. There is only one fan, kind of turbo fan, for the system and it’s powerful and noisy (especially during the few seconds on boot).
The model number of the RAM is K4S643232F-TC60. It is a 512K x 32bit x 4 Banks Synchronous DRAM LVTTL with the maximum frequency of 166MHz. It’s out of fashion these days but this switch could be dated back to 2003. It’s still useful for CCNA students, just like me 🙂
To my surprise, this switch uses a MAX3232 chip, the variation model of classical MAX232 (widely used for TTL to RS232 circuits, and I am very familiar with it. I could even find some ultrasonic distance sensing modules using MAX232 as a boost voltage source @~10V). It could be operated under 3.3V for a 3232 chip from my own experiences. My console cables have been arrived as well in another mail.
The last screenshot is about the console interface, and I am using putty with the COM1 port on the motherboard. I am planning to make a Raspberry Pi based Access Server by using USB to RS232 cable for remote access.
15/10/2014
Website Anti-bruceforce + Fightback to Hackers 网站安全加固,还击黑客穷举行为
By dch1 in Just Notes, Web Log No Comments
自从Linode前一个主机由于稳定性不佳导致整体迁移之后,这几天主机负载始终不正常,CPU图忽上忽下并且网站有异常流量,这就不得不让我关注网站是否除了情况(被注入?被攻击?还是搜索引擎收录?)。
主机没有装备控制面板,所以没办法,只好动手翻日志,看到了以下的内容:
原来是……近几天有人不断穷举我网站的密码啊,什么时候网站有此等知名度了,成为了某些人的眼中钉?
既然穷举,那我就装个插件吧,插件名叫做“Login Lockdown”,支持目前的Wordpress 4.0最新版本。谁知刚装完还没来得及测试,就发现了一个蠢蠢欲动的攻击者(PS:你运气真不好,今天被我盯上了,后文会说)。
这个IP地址显示是在泰国,我一般会随意看下这个IP是不是运行有其他服务,因为如果攻击者是租用的主机,那很可能该IP还运行有其他服务。我很意外的发现:
啥时候泰国也用上光纤了,这和我家里的登陆界面差不多啊(不过为什么内部管理界面可以直接访问到?)
可用用户名一般是user/user,确实可以登陆但权限不足!但admin/admin之类的组合不能用,看来是改了密码。
网上搜索一下,国内有相关资料显示admin账户的密码有可能会被篡改,所以我只好按照网上的方法查找密码。
我们先telnet一下,居然可以用!然后输入网站上给的一组用户名密码:root/Zte521,然后按照网站上的说明输入:
网站返回以下信息:
Oh Yeah! 果然返回了明文用户名和密码,一共系统就两组账户,一个admin/5624j0243,一个user/user。
剩下的不用多说了,直捣虎穴。
还是中文的,不用谷歌翻译了……剩下的不用我多说了。
总结 – Summary Time:
1. 互联网安全时刻要重视,如果自己的安全防护都做不好,何来攻击别人?
2. 保证网站的安全运行是IT从业人员的职责(升华够快,转眼怎么就成从业人员了……),Wordpress虽然是知名CMS系统,但安全防护也要做好,尤其是要定时升级,定期备份,定期监测系统信息。建议安装一些验证码登陆控件或者登录保护控件。