Disable IPv6 support in Ubuntu/Linux.

As many people know, Ubuntu supports IPv6 by default.
It's nice but sometimes you don't have chance to use IPv6 in your network environment.
And maybe, sometimes it brings few more complexity for your system administration tasks.

For example, if you set [i]listen_ip=[/i] in a services daemon's config file and hope it can listen to all of the IPv4 IPs of your network interfaces, you might not get what you want.

New Blog of BlueT.

This is the new Blog of BlueT.
The name GeekyLog is combined with the words Geek, Log, Blog, and Logic.
This blog is currently mainly for myself, to log some informations about me and my life experiences.

Currently I have 5 categories: Life, Ubuntu, CompuTech, [email protected], and Perl.
Most of all articales in this blog are licensed in CC-By-SA.
Any comments are welcome. And please help on spreading my GeekyLog and BlueT.org Studio to the world.

HOWTO: PPTP: Ubuntu Client connect to Windows VPN Server

The company I work for just starting to use Windows ISA Server (or whatever) in some places.
And also, they use the Windows server to be a VPN server.
As Micro$oft doesn't officially support OpenVPN, and we don't consider IPsec to be used for end users, they decide to use the fu*king insecure PPTP, which I would definitely never wanna try.
That's where my Nightmare starts.

After some tries, I can use the VPN on my Android phones, and it seems works fine on iPhone, too.

[Note] perlbrew + cpanm + perl 5.12.0

本文轉載自 使用 perlbrew 來安裝 perl-5.12.0 跟 cpanm 的筆記 - FourDollars Blog

perlbrew 的好處就是可以使用一般使用者的權限來安裝 perl 跟其模組,不用擔心會破壞到原本系統的穩定性。

首先去抓 gugod 在 GitHub 上的 perlbrew 接者開始安裝 perl-5.12.0

git clone git://github.com/gugod/App-perlbrew.git
cd App-perlbrew
./perlbrew install
./perlbrew init
source ~/perl5/perlbrew/etc/bashrc
perlbrew install perl-5.12.0
perlbrew switch perl-5.12.0

然後去抓 miyagawa 在 GitHub 上的 cpanm 回來安裝

Web Log Visualization

$ logstalgia --output-ppm-stream - -s 10 -f --start-position 0.01 --stop-position 0.2 severity_v2_access.log.filter-118.160.72 --output-framerate 30 | ffmpeg -y -b 256K -r 30 -f image2pipe -vcodec ppm -i - -vcodec libx264 coscup2010-register_0.01-0.2_speed10_45min-filter_118.160.72.mp4


It's ±€231 for my price.

www.ubuntu-tw.org reaches 1M hits per day, again.

[email protected] 正體中文站 討論區+wiki 又重回每日點擊百萬數了。
伺服器不穩定了好一陣子,現在終於重回當年盛況,每日點擊數超過一百萬! XD

KVM - build ubuntu guest, bridge network and iptables port forwarding

Once you install and setup KVM, configure kvm itself and system network bridge interface correctly on your Ubuntu server,
you can now starting to build a guest OS / disk image, run it, and use iptables to forward connections to those new VPSes.

Build guest:

HTTP_PROXY="Proxy_IP:Port" sudo ubuntu-vm-builder kvm hardy \
--dest 'DEST_DIR'\
--hostname 'GUEST_HOSTNAME'\
--arch 'i386'\
--mem '256'\
--rootsize '4096'\
--swapsize '1024'\
--kernel-flavour 'virtual'\
--domain 'bluet.org'\
--mirror 'http://ftp.twaren.net/ubuntu'\

How to flush / clean DNS cache in Linux

Sometimes your system caches too much on DNS query / records.

DNS caching helps alot on reducing time and bandwidth when your application needs DNS informations,
but just like anything else in the world; it's not a good thing when it does too over.

Let's see how to flush DNS cache in your system.

In Ubuntu:

$ sudo /etc/init.d/dns-clean restart
For Others:
Flush nscd DNS cache:

$ sudo /etc/init.d/nscd restart
$ sudo service nscd restart
$ sudo service nscd reload
$ sudo nscd -i hosts
Flush dnsmasq dns cache

$ sudo /etc/init.d/dnsmasq restart

HITcon 2009 WasGame 解題分享

這次很開心跟 Dark, H4K, TW1943 一起組隊玩 wargame.
當初預定拿 200 分的目標有達到, 雖然沒拿第一名不過重點是培養了團隊默契, 感覺真的很棒.
回想起四五年前和 devil2k 一起 team hacking 德國佬網站的日子, 到現在已經很久沒有這種感覺了.
謝謝你, 2963. 啊不是, 我是說, 謝謝你們, Zuso Security 的朋友們.

其實應該可以再拿 80 分的... 因為
guestbook 在最後十分鐘 admin 沒進來, 所以沒拿到 session.
有兩題 windows 題在時間結束後十分鐘內解出來

此次 windows 題都是 Dark 跟 H4K 解的, 我只能分享 Unix 跟 Misc.

此次大多用 Perl, Firefox + Firebug + LiveHttpHeaders, telnel, strings, VirtualBox + XP 等工具解題

Unix1: 看 source code 後, 把參數準備好餵進去就行了. 在 PATH_INFO 卡一陣, 後來 h4k 找到了.

Unix2: 用黑刀 dezend 在 winxp 解出 source code, 再讀一讀就出來了.


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