Category: Computers

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Stop Comment spams with IP Blacklist Cloud

Comment spams is the bane of any website operator that rely on real human interaction. Stopping comment spams by hand is a tedious process especially when comment spam attacks are sophisticated and are launched from Botnet. There are several techniques that can be employed to fight comment spams including behavioral analysis and also IP analysis.

In maintaining WordPress and Joomla sites, I myself has analyzed several web logfiles and Cloudflare logs to learn that most comment spam originated from certain ip blocks and countries. Therefore, I decided to completely deny access from those affected ip block through firewall (which keep the comment spam low and saves web server resources!)

ipblc_server

However, recently I found a new service IP Blacklist Cloud which list the top most blacklisted ip address through collaborative effort. Normally I find blacklisting by ip address is tedious and probably harmful to legitimate visitors, however after conforming the ip addresses that I found inside my spam logs, I decided the list is legitimate and decided to firewall-block some of the worst offenders in the list.

IP Blacklist Cloud free WordPress plugins, which I personally does not use due to my policy of keeping my installation lean with minimal (to no plugins!), however I see that there’s no harm giving a shot!

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How to check if your website supports SPDY 3.1

Although Google has announce to drop SPDY support by early February 2016 in favor of HTTP/2, SPDY remains the best HTTP protocol extension to maximize compression and reduce webpage load latency.

The current and final SPDY implementation supported by Mozilla Firefox and Google Chrome is SPDY/3.1.

In order to check if your webserver supports SPDY 3.1, just simply:

  1. Go to your website, eg: https://blog.mypapit.net/
  2. Using Chrome, type – “chrome://net-internals/#spdy” at the addressbar
  3. You should see your website name and spdy/3.1 protocol listed, refer to Screenshot below

spdy

Additionally, you could go to spdycheck.org to check if your web server supports SPDY.

Have fun!

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Tips for Securing SSH in Linux Box (Securing SSH Series)

Secured Shell or SSH is a great way to enable a secure login for your UNIX / Linux Box. However there are precaution that you should take in order to properly secure SSH daemon from being scanned or attacked by script kiddies or automated bots.

This week I’m going to write a series of article on securing SSH on Ubuntu Linux Box (VPS) and I’m going to link to this post from time to time.

  1. Disable Root login, enable SSH login for a handful of users only
  2. Install and configure Fail2Ban
  3. Limit access with Firewall Rules (limit by ip block, or ip address)
  4. Limit connection rate to SSH port
  5. Disable keyboard interactive login, Use public-key login
  6. Security Security through obscurity: Hiding SSH version
  7. Security Security through obscurity: Change default SSH ports

Hope this will help in securing your Linux Box / Linux VPS

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Top 5 things I do with my Ubuntu Linux

I haven’t had much time since I migrated my blog to a new VPS server. However, here is a little treat for all my readers out there. The top 5 things I do with my Ubuntu Linux:

  1. Surfing the internet
    Pretty obvious – I usually surf the internet using my Ubuntu Linux on my Desktop computer. I’ve a dual-monitor setup computer with Intel Core i5 CPU (12GB RAM), It is not a gaming pc, but I do occasionally play DOSBox games as well as Need For Speed: World from another operating system. The seamless Unity integration with the web intrigues me though, wished I had touchscreen monitor
  2. Developing Android Application
    The qemu-based Android device emulator runs nicely on Ubuntu, with no sign of lagging presents in other operating systems. Plus with 12GB of RAM, I can say that I could study and do mobile application with relative comfort. For Android 4.x development, I prefer to use the x86 images, because put less contraint on the CPU for skipping ARM-related code translation.
  3. Torrents
    Usually this is being done in parallel with other works. My current favorite bittorent client is Deluge. For some reason, I find Azureus/Vuze too cumbersome and I haven’t got around to use Transmission. I used to study bittorrent protocol in my spare time, but has since abandoned it when I realise that I’ve not much time to spend on side-projects anymore.
  4. Writing Manual
    I’m now in the process of writing a Lab Manual for those who just begining to learn about Mobile Computing. Although I wouldn’t call myself as an expert, I think every little bit of knowledge-sharing helps. I’ll promise I’ll share my progress with all of you sometimes at the end of the year. Though, I usually prepare my academic papers using Latex (IEEE templates), I choose to write my manual in LibreOffice, for reasons that I’m more familiar with WYSIWYG word-processor, plus, the publisher would prefer to receive the written manuscript in OpenDocument or Microsoft OpenXML file.
  5. Internet Radio
    Though I rarely if ever listen to MP3 in portable devices, I do listen to internet radio station from Rhythmbox. There are sizeable collection of preset Internet Radio station in Rhythmbox according to genre and age-group. I prefer to listen to trance or easy-listening radio stations.

There you go, the top 5 things that I usually do with my Ubuntu Linux. Nothing fancy, just that I prefer to use Ubuntu for reasons of application development. I’m a terminal-emulator typed guy. I prefer to switch/change the environmental settings using terminal emulator, something I find very easy to do in Ubuntu (or any GNU/Linux distribution for that matter).

Until next time…