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26/09/2014
Cisco WS-C2950G-48-EI
By dch1 in Just Notes, Life No Comments Tags: CCNA, Cisco, ICND1, ICND2
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.
27/09/2014
Shellshock Bash Vulnerability Identified in VPS
By dch1 in Web Log No Comments
I was informed by DigitalOcean that the Shellshock, with “破壳” named in Chinese, were identified in most of the Unix-alike systems. Well, it had raised my concerns when I read an article from Chinese sources yesterday so I’ve already patched the system and it is safe for 2 of my major VPS.
Vulnerability Identification: when I logged into the VPS shell, I used the command below:
If the VPS shell returned two lines of information, it means that system is vulnerable for this security issue.
Applying Patches: it is really easy for applying security patches for this security issue, just run:
and you are DONE!
Double check if we have a worry-free bash program: