IPv6 rebooted – web & smtp server

14 03 2012

Now that I had a new IPv6 allocation from tunnelbroker.net – it was time to get the server re-addressed & reachable from the outside world.

Apache was already configured to listen on all IPv4 & IPv6 addresses so all I needed to do was change the address, test connectivity & restart apache

sudo ip addr add 2001:470:489e::100/64 dev eth0
sudo route –inet6 add default gateway 2001:470:489e::1
ping6 2001:470:489e::1

Dont forget to update your nameserver

sudo vi /etc/resolv.conf
ping6 ipv6.google.com

Restart apache & postfix services

sudo /etc/init.d/apache2 stop
sudo /etc/init.d/apache2 start
sudo /etc/init.d/postfix stop
sudo /etc/init.d/postfix start

Update your DNS record with the new address & test connection.
You can either test from another IPv6 connected host (like a VPS)

ash@vertex:~$ dig aaaa public.blackundertone.com +short
2001:470:489e::100
ash@vertex:~$ curl public.blackundertone.com

Or use one of the many publicly available test servers – like http://ipv6-test.com/validate.php

Its as simple as that. Now my server was once again reachable via IPv6 – all this effort to get back to where I was.

Next time – I cover the DNS forward & reverse fun as well as why I needed to transfer my domain from namecheap.com free DNS hosting to the free DNS hosting provided by Hurricane Electric @ dns.he.net





ubuntu 11.04 natty screensaver hang issue

31 05 2011

Since upgrading to Ubuntu 11.04 I have been plagued by the dreaded locking screensaver / login / desktop issue after a period of time when the screensaver or blank screen is on. The symptoms of this are the screensaver appears to freeze without giving you the login box to enter your password, you can still move the mouse, you can still switch to a text console session.

This bug appears to be tracking it: https://bugs.launchpad.net/ubuntu/+source/gnome-screensaver/+bug/762918

A combination of killing gnome-screensaver & disabling VBlank in Compiz seems to have done the trick for me.

Putting this up here for anyone else who may be seeing this issue, hope it helps.

I switch to a console session using Ctrl+Alt+F1 & kill the gnome-screensaver

sudo killall gnome-screensaver

Switch back to X using Crtl+Alt+F7 & see if this fixed it & you can login again.

If not, you may also need to kill Compiz (I did)

sudo killall -w -s KILL compiz

Once back in gnome – you need to install the CompixConfig Settings Manager

sudo apt-get install compizconfig-settings-manager

Launch the compizconfig-settings-manager (Launcher, type compiz & click on the App) – then disable (Uncheck) the OpenGL option to “Sync to VBlank” under General / OpenGL

Doing this seems (fingers crossed, your mileage may vary) the problem.





100mb blank file

27 09 2010

I recently had the need to do some network testing, and came across a quick one liner to generate a blank 100mb file, thought someone else may find use for it too.

dd if=/dev/zero of=bigfile bs=1024 count=102400

This creates a file full of null characters (ASCII NUL, 0x00)
http://en.wikipedia.org/wiki//dev/null

dd if=/dev/random of=bigfile bs=1024 count=102400

This creates a file full of random characters
http://en.wikipedia.org/wiki//dev/random





hakin9 magazine

14 06 2010

Im glad to see this is now available online. Its been hard to get in Australia & at $15 or $20 a pop it adds up. Jump here & download the issues – some great articles to be had for n00b to l33t
hakin9.org magazine





a blog is born

8 06 2010

Well, here goes another one. Hopefully this blog will be kept more up to date than my last ones. As indicated in the about page (if you haven’t read it, go there so you know what to expect) – this is a place for all my thoughts, tips, tricks & general overflow for my brain on all things security.

Feel free to follow, comment or forget all about it 😀